BIO 1 - websites.rcc.eduwebsites.rcc.edu/tayyar/files/2019/12/White-1186-5-F19_Watermarked.pdf2 EXERCISE 1 The Scientific Method 1 2. Always carry your microscope with two hands. One

BIO 1Laboratory Manual

Microscope Number:

Department of Life Sciences Riverside City College

Fall 2019

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iiiBIO 1 Laboratory Manual

Table of Contents

1 The Scientific Method. . . . . . . . . . . . . . . . . . . . . . . . . 1

2 The Metric System and Basic Microscopy . . . . . . . . . . . . 11

3 Biological Molecules . . . . . . . . . . . . . . . . . . . . . . . . 27

4 Introduction to Cells, Molecular Movement, and Membrane Transport . . . . . . . . . . . . . . . . . . . . . . 41

5 Respiration and Photosynthesis . . . . . . . . . . . . . . . . . . 53

6 Cell Cycle, DNA Synthesis, Mitosis and Meiosis . . . . . . . . . 63

7 Introduction to Mendelian Genetics . . . . . . . . . . . . . . . . 75

Lab Practical 1 Review Sheet. . . . . . . . . . . . . . . . . . . . 93

8 Gene Expression and DNA Technology . . . . . . . . . . . . . . 95

9 Evolution and Natural Selection . . . . . . . . . . . . . . . . . .111

10 Kingdoms Bacteria, Protista, and Fungi . . . . . . . . . . . . . .119

11 Kingdom Plantae . . . . . . . . . . . . . . . . . . . . . . . . . .143

12 Kingdom Animalia. . . . . . . . . . . . . . . . . . . . . . . . . .155

13 Ecology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179

14 Conservation Biology . . . . . . . . . . . . . . . . . . . . . . . .189

Lab Practical 2 Final Review Sheet . . . . . . . . . . . . . . . .193


iv BIO 1 Laboratory Manual NOT FOR DISTRIBUTION - FOR INSTRUCTOR USE ONLY

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EXERCISE 1The Scientific Method

The purpose of this lab is to practice being a scientist. In this lab, you will learn how scientists approach research, and learn to develop your own research skills. This will include evaluating criteria for a good question, evaluating hypotheses, and how to design an experiment.

The scientific method is the approach that scientists use to conduct research. There are several steps in the scientific method. The first step is to make an observation about your surround-ings. These observations will form the foundation of the research, so careful observation is nec-essary. The second step is to ask a question about your observation. It is more difficult than you might think to ask a scientific question. The question needs to be narrow in scope and testable. The third step is to develop a hypothesis, an educated guess that is a possible answer to your question. The hypothesis needs to be testable and falsifiable. This means that you must be able to conduct scientific experiments to test whether your hypothesis is valid. Once you have de-veloped your hypothesis, you must design an experiment that allows you to test that hypoth-esis. While we do not have the time in this course to delve very far into experimental design, it is important to identify your independent variable (the parameter of your experiment that you, as the experimenter, will adjust) and your control (the parameter of your experiment that will be used to compare to the treatments). These items will be critical for determining the design of your experiment. Once your data are gathered, you will need to do statistical analysis to compare the results of your treatments to see if they are valid. At this point, you can determine if you will accept your hypothesis or reject it.

ACTIVITY 1

Laboratory SafetyScientific laboratories are exciting places with lots of activity and lots of people. This creates an environment that can become dangerous if we are not aware of our surroundings. It is impor-tant in a science lab to always be alert and aware of what is happening around you because an emergency can arise at any moment. There are several safety measures that will help to keep you safe in the laboratory environment, but they must be followed each and every time you are in the lab.

1. Always wear long pants and closed-toed shoes. This is very important for avoiding chemi-cal exposure to your skin and for protecting your feet from broken glass. We will be work-ing with both chemicals and glassware in the lab, so these are very real risks. To be safest, it is best to be covered up. Bare skin is much more vulnerable than covered skin, so reduc-ing bare skin is best to improve safety. Beyond wearing these lab-appropriate items, you should be aware that we will be using various stains in the lab. We use them to help us visu-alize parts of cells, but they can permanently stain your clothes or skin if they contact you.


2 EXERCISE 1 The Scientific Method

1 2. Always carry your microscope with two hands. One hand goes into the slot on the neck of the scope and the other hand goes under the scope. Do not lift the microscope using the stage or any other part of the scope. Our microscopes are precision equipment and must be treated very carefully. Also, be aware that the microscopes have small feet on the bottom. Be careful not to knock them off when sliding the scope back onto the shelf in the micro-scope cabinets. You will be introduced to the microscope in Exercise 4.

3. Because of the nature of the research being conducted in our building, if the fire alarm goes off you need to evacuate immediately. Follow the signs in the lab that direct you to the ap-propriate evacuation route. Remember, you may not smell smoke. Not all emergencies that require evacuation in a science building involve fire. Get out of the building immediately and move to the designated rendezvous location for your class. If the alarm goes off, it does not mean you are dismissed from class, so do not leave campus.

4. Please do not touch broken glass and do not put it in the regular trashcan. If you discover broken glass or accidentally break something glass, please alert your lab instructor and have them dispose of the glass safely. It needs to be put into the glass disposal area to avoid injuring someone in the regular trash.

5. Be sure you have read and understood the directions for each experiment before attending lab. You should read the lab exercise ahead of your scheduled lab time. Not following the instructions can result in failed experiments, which can result in losing points on assigned data summaries. Furthermore, not following instructions can put you or your study organ-ism at risk, both of which are unacceptable circumstances.

6. Because of the types of experiments we do and the types of dangers present in the room, it is important to know the types of safety equipment in the lab. There is a fire extinguisher in case of fire, an eyewash in case you get chemicals in your eyes, and there is a chemical shower in case you get chemicals on your skin. All of these types of safety equipment are located near the exit to the classroom. You want to familiarize yourself with their location in case of an emergency. Of course, this equipment is only for use in emergencies and should never be used for any other reason.

7. Your lab instructor may ask you to take a picture of how the lab is set up when you first enter the room. It is important to understand that you are responsible for cleanup (at your lab bench, at the sinks, and anywhere else in the room). One way to be sure to get the room cleaned up correctly is to refer back to your photo of how the room was set up when you came in. Allowing phones to be out in the room is up to your lab instructor, so do not dis-obey their instructions. However, if they allow it, taking a picture can be very helpful at the end of lab.

As scientists, we often work in groups. Research is a collaborative effort that requires input from many other people. As such, we will often work in teams in lab. Do not confuse teamwork with group assignments. For each homework assignment it will be expected that you do your own work and turn in your own assignment. While you will work in groups during lab and discuss your outcomes, it is not appropriate to turn in someone else’s work as your own. When scientists work together on a research project, everyone’s name is included on the paper. Be sure you are doing your own work and not using answers obtained from your group members. When your name is on the paper, you need to be sure you have genuinely done the work.

Additionally, it is expected that all work will be done at a college level. You should be using correct grammar, spelling, and punctuation and writing in complete sentences. Failure to do so can result in lost points.


3EXERCISE 1 The Scientific Method

ACTIVITY 2

Experimental Design

Designing a Testable QuestionHow do you define the problem you wish to investigate? Every investigation begins with a question that the scientist wants to answer. Questions are answered by scientific observations, information gathered through previous research, or both.

Can all questions be answered scientifically? Absolutely not.

Working in pairs, or small groups, decide which of the following questions can be answered by the scientific method. Be able to explain your reasoning!

• Are serial killers evil by nature?

• What is the cause of Mad Cow Disease?

• Why is grass green?

• What is the best recipe for chocolate chip cookies?

• Did extraterrestrials construct the Grand Canyon?

What do you think determines whether a question can be answered scientifically?

Developing a HypothesisOnce a question has been formed, the next step is to construct an appropriate hypothesis. Hypotheses are nothing more than early explanations that attempt to answer the question you’ve posed. A good hypothesis provides a rationale/justification along with the explanation. Remember, there is no rule governing the length of a hypothesis!

Not all hypotheses are created equal! In fact, some hypotheses are of no scientific value at all since they are not testable.

Again, working in pairs or small groups, decide which of the following would be useful as a scientific hypothesis. Be able to explain your reasoning!

• Plants absorb water through their leaves as well as through their roots.

• Mice require calcium for developing strong bones.

• Dogs are happy when you give them steak.

• All dogs go to heaven.

• Syphilis can be transmitted by toilet seats.

A scientific hypothesis must be both:



1 Dependent and Independent VariablesAn independent variable is what the investigator deliberately changes (e.g., concentration, tem-perature, pH).

A dependent variable is what is measured by the investigator in order to learn the effect of changing the independent variable.

Keep in mind that constant variables must be controlled and standardized. All variables (with the exception of the variable being tested) must be kept constant! Think of constant variables as factors that should be standardized for an experiment.

What are some variables that should be standardized for the following experiments?

The effect of fertilizer on the yield of tomatoes.

The effect of a drug on lowering blood pressure in a group of humans.

ControlsAll experiments require at least one control (and often more than one) in order to eliminate the effect of a variable or else to determine the standard value. A control must be identical to the experimental treatment except for the one variable being tested. In this way, a control is used to “zero-out” the effects of other factors.

ACTIVITY 3Everybody is a scientist! What distinguishes science from other disciplines is that science uses a methodical and repeatable process that generates objective evidence about the world around us. In this activity you will learn about the scientific method and how to apply the method to learn about nature.

Your lab instructor will demonstrate the steps of the scientific method. In the box below, make a flowchart that indicates the steps in the scientific method.



You and your lab partner will think of something interesting you have observed on campus or at home. Once you have decided on a specific observation, write it below. Have your lab instructor approve your question and hypothesis.

Observation

Question

Hypothesis

ACTIVITY 4

The Scientific Method in Action

Designing and Performing an ExperimentWhat makes a “Class Champion” thumb-wrestler? In this activity, we will explore whether the size of the palm of the hand between the base of the pinky finger and the base of the thumb has an effect on the overall chances of winning a thumb-wrestling match.

You will develop a hypothesis and then test this hypothesis by conducting a thumb-wrestling tournament to determine an overall “Class Champion.”

Choose a partner and perform the following measurement in centimeters (as shown in the drawing below) using the metric tape on your lab bench. Then have your partner perform the same measurement on you.

Record your measurement here

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Please develop a hypothesis regarding the possible outcome of this experiment.

Hypothesis:



1 Rules of Thumb Wrestling:Two players grasp hands; they touch thumbs to the opposite sides of the other person’s hand three times, then come out wrestling. The object is to hold the other person’s thumb down for a count of three using only your thumb. You must win 2 out of 3 “games” to win your match. Every student plays every other student.

Analysis and ConclusionWhat have we learned from this experiment? To understand what the results of our experi-ment are, we have to compare the results of the entire class.

Did those individuals with larger measurement win more of their matches?

Do the results support or falsify your hypothesis, or is the data inconclusive?

What is the independent variable in this experiment?

What is the dependent variable in this experiment?

List the constant variables in this experiment.



Table 1. Record of wins and losses in thumb wrestling matches.

Opponent Game Wins Game LossesI Won the

Match (Y/N)

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

ACTIVITY 5

Dissecting MicroscopeDissecting scopes are used to investigate the surface of samples. Rather than pass light through a sample as the compound microscopes do, dissecting scopes shine light on the surface of the sample. This will allow you to see unique characteristics of the surface of plants, animals, or other samples. The dissecting scopes used in this lab contain an internal light source, so they only need to be plugged in and turned on in order to work. To use the dissecting scope, just place your sample under the lens. Looking through the eyepiece, adjust the focus until the sample is clearly visible to you. Because you are looking at the surface of a sample, you may have to alter the focus depending on the topography of the sample.

To practice with the dissecting scope, you should look around campus for samples (or you may be provided with specimens). Look for leaves that are bumpy, hairy, or textured. Look for insects that move slowly or have expired. Look for flowers, stems, roots, or rocks. Look for anything that has an interesting surface: your hand, coins, keys, and others. You will not be disappointed when you view that surface under the dissecting scope.



1

Stage plate

Zoom controlknob

Focusingknob

Stand

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Eye piece

Diopteradjustmentknob

Body clampingknob

Microscope body(contains lens)

ON/OFFswitch

Brightnesscontrol dial



Worksheet Name Section

Date

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1The Scientific Method

This worksheet is to be completed while reading Exercise 1 and is due when you next have lab. You are expected to do your own work. You do not have to type your answers, but please write legibly.

1. List the first three steps of the scientific method in order.

a.

b.

c.

2. Which of the questions below can be answered scientifically? (Circle the letter of all correct answers.)

a. How far can a kangaroo rat jump?

b. Do skunks dislike squirrels?

c. How much water is necessary to keep grass green?

d. Are people who don’t like spicy food physically weak or just weak in character?

3. A good hypothesis includes which of the following? (Circle the letter of all correct an-swers.)

a. Testable elements

b. Data analysis

c. Explanation

d. Calculation

4. Which variable is the one that is adjusted by the experimenter? (Circle the letter of all cor-rect answers.)

a. Dependent variable

b. Independent variable

c. Constant variable



1 5. Of the following, which are required for personal safety in lab? (Circle the letter of all cor-rect answers.)

a. Long pants or a long skirt that covers the ankles

b. Goggles

c. Hat or hood

d. Closed-toed shoes

e. Snake gaiters

f. Waterproof boots

g. Lab coat

6. What do you do if the fire alarm goes off but you don’t smell smoke? (Circle the letter of all correct answers.)

a. Stay where you are. Some chuckle-head probably pulled the alarm to avoid a quiz.

b. Get out of the building and move to the designated rendezvous location.

c. Wait for directions from your lab instructor or other faculty or staff.

d. Go home immediately.

7. True or False? Because students will often work in teams during lab, it is appropriate for a student to copy homework answers from their team members.

8. The morning before a Biology 1 midterm, half of the students in a class were given plain water for breakfast while the other half were given an energy drink. The average exam scores of the two groups were compared to see if the type of drink has an effect on the students’ grades.

a. What is the dependent variable in this study?

b. What is the independent variable in this study?


11

EXERCISE 2The Metric System and Basic Microscopy

The purpose of this lab is to learn about the metric system and basic microscopy. You will learn the metric system, including how to take measurements using metric units. Additionally, you will learn about microscopes and microscope care and maintenance. You will be asked to mea-sure various objects, including cells, in the metric system. This lab may require you to walk around campus, so please dress accordingly for the weather.

ACTIVITY 1

Scientific NotationIn an effort to avoid confusion and to maintain the highest levels of accuracy, scientists utilize scientific notation when reporting large or small values. This method prevents readers from having to count decimal places or zeros. Numbers represented in scientific notation have one digit before the decimal point. All remaining significant digits follow the decimal point. This number is multiplied by the appropriate factor of 10 to represent the original number. If the original number is smaller than 1, the exponent on the factor of 10 will be negative. If the origi-nal number is larger than 1, the exponent on the factor of 10 will be positive.

For example, to represent the number 20045 in scientific notation:

• Insert the decimal point after the first non-zero whole number digit of the original number: 2.0045

• Determine the exponent on the power of 10 that is appropriate by counting the number of spaces the decimal point has moved. In this case the decimal point has moved 4 spaces. The exponent is positive because the original number is much larger than 1.

• Represent the number in the following form: 2.0045 # 104

To represent the number 0.03984 in scientific notation:

• Insert the decimal point after the first non-zero whole number digit of the original number: 3.984

• Determine the exponent on the power of 10 that is appropriate by counting the number of spaces the decimal point has moved: in this case the decimal point has moved 2 spaces. The exponent is negative because the original number is smaller than 1.

• Represent the number in the following form: 3.984 # 10−2


12 EXERCISE 2 The Metric System and Basic Microscopy

2 Exponents: 1 = 100 1.00 = 100

10 = 101 0.10 = 10−1

100 = 102 0.01 = 10−2

1,000 = 103 0.001 = 10−3

10,000 = 104 0.0001 = 10−4

100,000 = 105 0.00001 = 10−5

1,000 # 1,000 = 103 # 103 = 106 or 1,000,000

1,000,000 ' 1,000 = 106 ' 103 = 103 or 1,000

1/1,000 # 1/1,000 = 10−3 # 10−3 = 10−6 or 1/1,000,000 or 0.000001

Try This!Write the following numbers in scientific notation:

324567 =

0.004567 =

23456000 =

ACTIVITY 2

The Metric System and Metric ConversionsAlthough the metric system is used in nearly all other countries in the world, the United States continues to use English units such as the pound for mass, the mile for distance, and the gal-lon for volume. In the sciences, the metric system is used for all measurements including dis-tances, volumes, masses, and temperature. In this lab, you will become familiar with the metric system and converting from one metric measure to another.

The Units of the Metric SystemThe metric system is based on basic units. For length the base unit is the meter, for volume the base unit is the liter, and for mass the base unit is the gram. For example, if we used the base unit of length in the metric system, a trip from Riverside to downtown Los Angeles would be roughly 80,000 meters. Wow! That is a large number. Is there a way to simplify this number? The metric system has many prefixes to help simplify very large or very small values. By add-ing a prefix before the word “meter,” we can alter the outward appearance of the value. The most common prefixes that will be used in this course are kilo-, deci-, centi-, and milli-.


13EXERCISE 2 The Metric System and Basic Microscopy

deci

centi

milli

micro

large

small

Kilo

If you move from the base unit up toward the prefix kilo- and place “kilo” in front of the word meter, you are describing a distance that is composed of many meters: a kilometer. If you move towards the prefix micro, you are describing a measurement that is much smaller than a meter: a micrometer. How are these prefixes related to each other?

K Base d c m nμ

To understand how the prefixes are related to each other, let’s try an example. In the box marked “Base Unit” insert the word meter.

First, let’s look at values smaller than the meter. In every meter, there are 10 decimeters. In one decimeter, there are 10 centimeters. In one centimeter there are 10 millimeters. In one millime-ter, there are 1,000 micrometers. See how the prefix is added to the base unit “meter”? What would we do if we were measuring in grams?

K Base d c m nμ

Now, let’s look at the values larger than the meter. In order to have one kilometer, we would need 1,000 meters!

Common Metric PrefixesUNIT EXAMPLE

(k) kilo = thousand—1 kilometer has 1,000 meters

(d) deci = 1/10 of the base unit—1 meter has 10 decimeters

(c) centi = 1/100 of the base unit—1 meter has 100 centimeters

(m) milli = 1/1,000 of the base unit—1 meter has 1,000 millimeters

(μ) micro = 1/1,000,000 of the base unit—1 meter has 1,000,000 micrometers

(n) nano = 1/1,000,000,000 of the base unit—1 meter has 1,000,000,000 nanometers

Try This!

1.68 m = cm

0.057 kg = g

250 ml = μl



2 ACTIVITY 3Determination of LengthBeing able to use a metric ruler is very important in scientific study. All measurements of length will be made using metric units, but the type of unit used will vary depending on the object being measured. In this lab, we will use centimeters and millimeters most commonly. To familiarize ourselves with these units, we will practice using blocks. Obtain two blocks and measure the longest length of the block. Record your measurements in the table below.

Length of Block

Determination of MassThe mass of an object is another consideration for scientific studies. In biology, often the mass of a small object such as a seed or insect wing is needed. Precise measurement requires some-thing more accurate than the bathroom scale! In the scientific laboratory a balance is used for precise measurements. For this laboratory project, significant accuracy can be obtained using the electronic balance. Accuracy for this balance is to 0.01 g. Instructions for the use of the bal-ance will be given in the laboratory.

Using the electronic balance, weigh two blocks. Record the mass for each block in the table below.

Mass of Block

Determining Volume of LiquidsDuring many procedures, scientists and technicians often must accurately transfer a given amount of solution. In the laboratory, a graduated cylinder is used. A graduated cylinder is a glass or plastic cylinder with graduations for measuring liquids.

Using the graduated cylinder, you will notice that liquids cling to the sides, creating a U-shaped appearance to the top of the fluid column. This U-shaped meniscus results from the cohesive and adhesive properties of liquids, particularly those containing water, and the glass or plastic of the container. To read the volume of liquid in a graduated cylinder, the value is taken at the bottom of the meniscus.

3

2

To measure liquids in a graduated cylinder, read the lowest liquid level (the bottom of the meniscus).



Beakers and graduated cylinders are used in the laboratory to measure small amounts of liq-uid. When measuring a liquid in a graduated cylinder remember to look at the meniscus when determining the volume of the liquid.

Next, you will use the graduated cylinders at your lab station to measure the following liquid volumes: 3 ml, 5.5 ml, and 7.8 ml. Practice first with the blue liquid provided at your lab sta-tion. Once you feel confident with the blue liquid, try tap water.

Now try using a larger graduated cylinder. Try measuring the following liquid volumes: 23 ml, 18 ml, 38 ml, and 42 ml. Notice that the graduations on different sizes of graduated cylinders represent different volumes of liquid. In some cases each graduation is a milliliter, in other cases it may only be 1/10th of a milliliter, or it may even be 5 milliliters. Be sure you are mea-suring correctly!

Next, place an arrow at the 4.8 ml mark on the syringe shown below.

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Temperature MeasurementsIn the sciences, a thermometer is used to measure the temperature of liquids. Although we may be used to looking at temperature in Fahrenheit, scientists use Celsius for temperature measurements.

Using the thermometer provided, measure the temperature of the following in Celsius:

Temperature in Celsius

Room Temperature

Tap Water

Ice Water

Surface of Your Skin

ACTIVITY 4

Basic MicroscopySince the human eye is unable to distinguish objects smaller than 0.1 mm, observation of cells is dependent upon the use of the microscope. The role of the microscope is to provide both magnification of an object as well as resolution, which is the ability to distinguish between two adjacent objects. It is this quality of resolution which provides contrast and the ability to distinguish detail in materials being observed.

Several types of microscopes are used in biological observation and differ on the basis of the type of energy source and lens system. One microscope that you will use in today’s laboratory and in subsequent labs is the light microscope: the most commonly used in biological observa-tion. Because the light used to illuminate specimens is focused through two sets of glass lenses, this microscope is commonly called the compound light microscope. The compound light mi-croscope is limited to 1,000#–2,000# magnifications and a resolving power of 0.2 micrometers.



2 The electron microscope uses a beam of electrons as the energy source. Resolution with an electron microscope provides 0.002 to 0.005 micrometers and magnifications up to 500,000#. In transmission electron microscopy, electrons are focused by electromagnetic coils. Electrons travel through the specimen at different rates giving a high resolution, one-dimensional pic-ture of the cell. In scanning electron microscopy, electrons bounce off the surface of the speci-men giving a three-dimensional image of the cell surface.

These are scanning electron microscope images of the surface of a common soil insect com-monly known as the springtail because the insect uses the tail to “spring” from place to place. These particular insects are barely visible with the naked eye. The image below is the tail with several scale-like structures and the image to the right is a scale in detail. The magnification of these images is located below the pictures.

15,000# 25,000#

Contrast the scanning electron images with images from the transmission electron microscope. You can do this by visiting http://www.cellsalive.com

Components of the Light MicroscopeIn order to fully benefit from the tools the compound light microscope provides, it is important to know the names of microscope components and how they work. First, it is important to know how to carry and set up the microscope. Always carry the microscope with two hands: one hand holding the microscope by the arm and one hand supporting the underside of the scope. Once you set the scope on your lab bench, plug the scope into the electrical outlet, and flip the switch to turn on the light source. The light source shines from the bottom of the scope upwards toward the stage of the microscope. The stage is a platform where microscope slides are placed for viewing. Slides are held in place with clips so that they will not move during viewing. The light travels towards the stage through the iris diaphragm, which has a small lever that allows you to regulate the amount of light traveling through your specimen to get the best contrast of light and dark. The image of the specimen passes through the objective lens attached to the revolving nosepiece. The image can be brought into sharper focus using first the coarse adjustment and then the fine adjustment. Finally the image of the object passes through the ocular lens, which has a magnification of 10#. The microscopes in Biology 1 have two ocular lenses, so they are called binocular scopes.

It is important to make sure that the lenses stay clean. Avoid touching the lenses. If the lens requires cleaning, make sure to ask your instructor to show you how to clean the lens with lens paper only. Other materials scratch the delicate lenses.



Below is a diagram of a compound light microscope similar to the one you will use in Biology 1.

Oculars

Revolvingnosepiece

Objectivelenses

Scanning power (4X)

High power (40X)

Low power (10X)

Platformstage

Light

Base

Y axis

X axisMechanicalstage

Fine focus

Fineadjustment

Condenseraperture diaphragm

Coarseadjustment

Arm

ON/OFFswitch

Brightnesscontrol dial

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Focusing the Light MicroscopeAs discussed, the microscopes you use will have three objective lenses: a 4# scanning lens, a 10# low power lens, and a 40# high power lens. The objective lens magnifies the specimen by the number on the lens; for example, the scanning lens magnifies objects four times. Always begin to observe your slide with the 4# lens. If the object is out of focus, use the coarse adjust-ment to bring the object into focus. The coarse adjustment moves the stage either closer or farther from the objective lens to bring objects into focus. Because the stage moves so quickly, never use the coarse adjustment at 40#! (You may damage the objective lens.) If you want to bring the image into sharp focus, use the fine adjustment. Using the fine adjustment is almost always necessary at 40#.

Once the object is in focus and you desire a higher magnification for more detail, rotate the nosepiece so the 10# objective is over the object. Again, use the coarse adjustment and fine ad-justment to bring the object into sharp focus. You may also find that at a higher magnification, more light is needed to illuminate the object. Finally, to see the most detail, rotate the nosepiece so the 40# objective is over the object. Use only the fine adjustment to bring the image into sharp focus.

When using the microscope, it is important to always keep in mind the magnification of the image. Magnification is determined by multiplying the magnification of the objective lens by the magnification of the ocular lens. For example, if the objective lens in use is 10# and the ocular lens is 10#, the total magnification of the object is 100# because 10 # 10 = 100.



2 As you progress from lower (scanning lens) to higher powers of magnification, note the re-lationship of the working distance: the space between the top of the slide and the end of the objective lens. The higher power lenses decrease the working distance while low power lenses allow for a larger working distance.

When changing objective lenses notice the effect on the size of the field of view. The field of view is the area of the microscope slide that can be seen at one time. As the magnification increases, what happens to the field of view? Finally, the degree of brightness of the field changes as magnification changes.

ACTIVITY 5

Microscope Image OrientationLook at the letter “e” on the slide before you put it on the stage of your microscope. Is it right side up or upside down? Now observe the slide of the letter “e” at 4#. What happens to the orientation of the letter when it is viewed through the microscope?

What happens to the orientation of the letter when it is viewed through the microscope?

When you move the slide to your right, in which direction does the image move in the field of view on the microscope?

Try to move the image down in the field of view. Which way did you have to move the slide?

Draw what you see when you look at the letter “e” on scanning power.

Size and Brightness of Field of ViewWith the same slide in place, progressively move from 4# to 40#. Note the working distance between the objective lens and the slide at each magnification.



What happens to the size of the field of view and its brightness?

Do you need to increase or decrease the amount of light passing through the specimen at higher powers of magnification?

If you know the diameter of the field of view at each magnification, it is possible to estimate the size of the objects in the field. To measure the diameter of the field of view, place a translu-cent ruler on top of a blank glass slide and place both on the microscope stage as if they were a prepared slide. Place the slide and ruler on the scope so that the light passing through the diaphragm in the center of the stage illuminates the metric side of the ruler. Using the 4# objec-tive lens, look through the microscope and focus on the ruler. Place the millimeter marks on the ruler in such a position that they line up across the very center of the circle, or field of view, as shown in the figure that follows:

Using the ruler as your guide, estimate the diameter of the field of view in millimeters at the scanning (4#) power. Record your values in the following table. Note that there is a conversion from the millimeter value you obtained to the more commonly used microscopic measure-ment, micrometer (μm).

Lens Magnification mm in Field of View μm in Field of View

Scanning

Try These!On the basis of your measurements, what is the approximate size of the letter “e”?

What would be the size of an object (in mm) that occupies 25% of the size of a field of view that is 3.2 mm in diameter?



2 Human Cheek Epithelial CellsNow, you are going to look at your own cells!

You will make a fresh wet mount of your cheek epithelial cells for microscopic observation! To do this, gently scrape the lining of your cheek with a clean toothpick. Carefully wipe the end of the toothpick on a slide. Before adding a coverslip, add one drop of methylene blue to the cheek cell smear. Look at the cells at low power first and then increase the magnification so you can identify the nucleus, cytoplasm, and the outer limits of the cell at the cell membrane. Some other organelles may be visible as tiny spots in the cytoplasm. You may also see tiny specks outside of the cells that may be bacteria which are normal inhabitants of the mouth.

Draw a few of your cheek cells below!

Total magnification



ACTIVITY 6

Metric Scavenger Hunt (if time permits)Using your knowledge of the metric system, you will need to work in groups of up to 4 stu-dents to measure the items listed in the table below. Hopefully, these measurements will help give you a practical reference for the types of metric measurements we will use frequently during the semester.

Table 2.1. Measurements collected on the metric scavenger hunt.

Object Measurement

Length

Cell phone

Pen

Coin

Mass

Cell phone

Pen

House key

Volume

Pen

Coin

House key



2



Worksheet Name Section

Date

Staple here

2The Metric System and Basic Microscopy

1. For which of the following microscopes were you provided operational instructions? (Circle the letter of all correct answers.)

a. Scanning electron microscope

b. Transmission electron microscope

c. Light microscope

2. How many hands should you use to carry a microscope? (Circle the letter of all correct answers.)

a. I lift weights. I’m strong. No biggie.

b. One under the base and one in the slot on the arm.

c. Get help from a lab partner so that you don’t risk dropping it.

d. The more the merrier.

3. Where are the slides placed on the microscope for viewing?

4. Which lenses are attached to the revolving nosepiece and can be adjusted to achieve the desired magnification? (Circle the letter of all correct answers.)

a. Ocular lens

b. Objective lens

5. Which adjustment knob do you use when using the 40# lens? (Circle the letter of all correct answers.)

a. Fine adjustment knob

b. Coarse adjustment knob



2 6. To determine the magnification of the object, what do you multiply? #

7. In scientific notation, how many non-zero digits are acceptable before the decimal point?

8. In scientific notation, if the number you are representing is larger than 1, is the exponent on the factor of ten positive or negative?

Practice Problems9. Write the following numbers in scientific notation.

a. 3,500 g =

b. 24,000 ml =

c. 1,313,000 nl =

d. 400,000 m =

e. 354,000,000 ml =

f. 0.00093 kg =

g. 0.00000045 dm =

h. 45,987 μl =

i. 0.0037 cg =

10. Write the numbers represented by scientific notation.

a. 6.87 # 105 km =

b. 4.5 # 104 cl =

c. 2.1 # 10−3 dg =

d. 3.5 # 10−2 m =

e. 9.1 # 104 μl =

f. 6.77 # 101 dm =

g. 4.5 # 10−5 kg =

h. 2.0 # 102 μl =

i. 9.9 # 10−2 dm =



11. Complete the following problems. Please show your work for all conversion problems.

a. 2.3 cm to mm

b. 8.73 kg to g

c. 54 L to ml

d. 14 km to m

e. 90.8 dm to mm

f. 76 μl to ml

g. 16.2 g to mg

h. 74 mg to g

i. 451 μl to ml

j. 25 dg to mg

k. 2.2 mm to μm

12. Hepatitis B virus (HBV) is approximately 50 nm. How many mm would that be?



2


27

EXERCISE 3

Biological Molecules

The purpose of this lab is to learn the major types of biological molecules. For each group of biological molecules, you will be introduced to the general characteristics, the general struc-ture, and the function of each group of molecules in living organisms. You will build models of the biological molecules using molecular models. Additionally, you will test for the presence of these molecules in different food/beverage items.

ACTIVITY 1

A Review of Chemical BondingElements are made up of which contain two particles in the nucleus (called (+) and (0)) and (-) that orbit around the . Atoms can combine to form . Each molecule is held together by .

One type of bond that holds molecules together is the bond where electrons are permanently given away or taken to form ions. These ions are held in the bond with electro-negative charge. An example of a molecule with this type of bonding is .

Another type of bond that holds molecules together is the bond where elec-trons are shared. If the electrons spend equal time around each atom it is called a bond. An example of a molecule with this type of bonding is . If the electrons are pulled toward one atom more of the time, it is called a bond. An example of a molecule with this type of bonding is .

ACTIVITY 2

Introduction to Biological MoleculesThis lab focuses on the four groups of biological molecules:

Carbohydrates

Lipids

Proteins

Nucleic Acids


28 EXERCISE 3 Biological Molecules

3 Constructing Biological MoleculesMany of the important biological molecules consist of carbon and hydrogen atoms. Most of the time, biological molecules have functional groups. Functional groups are groups of atoms that change the characteristics of a molecule. For example, if a hydroxyl group is added to a mol-ecule, the molecule will become more polar. Below are four biologically important functional groups. Please memorize their names, structure, and examples of where each can be found.

Functional Group

Hydroxyl

Carboxyl

Amine

Phosphate

Example

glucose

fatty acid

amino acids

nucleotide

OH

NH

H

C OH

O

P O

O

O

O

Structural Formulas and Molecular FormulasToday we will be examining both structural formulas and molecular formulas. A structural formula gives the orientation of the atoms relative to each other in space. The molecular for-mula represents the types of atoms found in the molecule and the number of each type of atom. For example, the molecular formula for glucose is C6H12O6 but the structural formula is diagrammed below.

O

CH2OH

OH

OH H

H

H

H

OH

H

OH

Glucose

What Do You Think?Is water an organic molecule? Why or why not?

What type of bonding exists between atoms of the water molecule?


29EXERCISE 3 Biological Molecules

How many atoms can bind with hydrogen? With oxygen? With carbon?

Why do you think life is based upon carbon?

Which functional group is the most polar? Why?

Building a Water MoleculeUsing the molecular sets, you and your lab partner will build your first molecule: water. In the molecular sets, carbon atoms are black, oxygen atoms are red, and hydrogen atoms are white. Bonds are represented with plastic white tubing. As you build your water molecule, please answer the following questions.

What elements make up water?

What is the molecular formula of water? What is a molecular formula?

What does the subscript number 2 following the H represent?

How many molecules of water are represented by the formula H2O?

After building your water molecule, draw the structural formula of water here:

What do the lines between H and O represent?



3 ACTIVITY 3Carbohydrates

Building a CarbohydrateCarbohydrates are most often used for energy by living organisms and may be used for struc-ture. The cell walls of plants, fungi, and bacteria contain the carbohydrates cellulose, chitin, and peptidoglycan, respectively. The monomer of a carbohydrate can be a five or six carbon sugar called a monosaccharide. These are usually found in nature with the carbon atoms linked together in a ring as shown below. Each carbon is numbered according to the order it is found in the ring.

C

C

C C

O

C C

1

23

4

5

6

Glucose ring structures have two forms: alpha and beta. Look at the diagrams below. If the hydroxyl group on carbon 1 is in the same direction as the hydroxyl group on carbon 4, the glucose is in alpha form. If these hydroxyls point in opposite directions you have made the beta form.

O

CH2OH

OH

OH H

H

H

H

OH

H

HO

alpha glucose

O

CH2OH

OH

OH H

H

H

OH

H

H

HO

beta glucose

Although these structural differences appear slight, they create important functional differ-ences. Alpha glucose molecules form long chains called starches which can be easily digested by animals. Beta glucose molecules form polymers of cellulose which make up the cell walls of plants and most animals cannot digest them.

A disaccharide is formed when two molecules of sugar bond together. In order for these two monomers to come together, a condensation reaction must occur. During condensation, mol-ecules are bonded together by removal of a hydrogen atom from one monomer and a hydroxyl group is removed from the other monomer to form water. To break the bond between mono-mers, water is added back in a process called hydrolysis.



O

CH OH

OH

OH H

H

H

H

H

OH

H

HO

glucose

O

CH OH

OH

OH HH

H

H

H

OH

HO

H

galactose

C

C

C C

C

CH OH

OH

OH H

H

H

H H

HOH

fructose

C

C C

CC

CC

C

C O

C OH

MonosaccharidesExamine the structural formulas of the three monosaccharides glucose, fructose, and galactose.

How many atoms of carbon are there in each molecule of glucose? In fructose? In galactose?

Write the molecular formula for glucose, fructose, and galactose.

Molecules of monosaccharides may have the same molecular formula but differ in their three-dimensional structure. This is called isomerism.

Can you define isomerism in your own words here?

Build two alpha glucose molecules. Using your models, link the two alpha glucose monomers together using a condensation reaction.

Maltose

1

23

4

5

6

1

23

4

5

6

H

OH

H OH

HHO H

H

O

CH2OH

H

OOH

OH

H OH

H

H

CH2OH

H

O

You have now formed maltose—two alpha glucose monomers.

Now link all of the glucose molecules from your lab bench together. Once you have one poly-mer per lab bench, link the polymers together to form a short starch chain. Notice how much larger starch is than the individual glucose molecules.



3 A Sugar Taste TestHave you ever wondered why a certain sweetener is used in foods while another is not? Which type of sugar is the sweetest? In this activity you will taste three different sugars and three ar-tificial sweeteners and rank them on the basis of sweetness—the sweetest will rank as number one and the least sweet will rank as number six. Follow the instructions of your lab instructor carefully.

Ranking Comments?

Glucose

Fructose

Sucrose

Sweet and Low

Equal

Splenda

ACTIVITY 4

Lipids

Building Lipid MoleculesLipids contain the same elements as carbohydrates but with fewer oxygen atoms. Lipids are excellent energy sources in cells and are also used for insulation, vitamin synthesis, and as water repellant for fur and feathers. There is not a true monomer for lipids. Today we will ex-amine triglycerides and fatty acids.

Triglycerides are formed from one molecule of glycerol and three fatty acids. What elements are present in glycerol? The three fatty acids are added to glycerol using dehydration synthesis. The fatty acid can be made of just a few carbon atoms linked together in a chain as in butyric acid or with many carbons linked together, as in lauric acid.

What is the ratio of carbon to hydrogen in these acids?

What is the difference between saturated and unsaturated fatty acids?

What functional group is found in every fatty acid?



OHOH

H

H C

H

H

CC

OHH C

OH

H

H C

O H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C H

H2O

glycerol fatty acid

ACTIVITY 5

Proteins

Protein MoleculesProteins are made from long chains of amino acids. Amino acids have a carboxyl group on one end and an amine group on the other end. The generalized form of an amino acid is below:

amino acid

H

RH OH

N C

OH

C

There are twenty different amino acids found in plants and animals. A diagram of all twenty amino acids can be found at the end of this lab.

The simplest amino acid is glycine. What is the molecular formula of this molecule?

How is alanine different from glycine?

Amino acids are linked to make polypeptides using condensation reactions.

What Do You Think?Why are proteins called polypeptides?



3 What elements are always present in amino acids?

What functional groups are always present in amino acids?

EnzymesEnzymes are proteins that catalyze the reactions of life. A basic understanding of how these molecules work is essential to an understanding of biology.

All organisms use enzymes as catalysts to increase the rate of a chemical reaction without in-creasing the temperature needed for the reaction. For each reaction in the cell, there is at least one specific enzyme facilitating the reaction.

Enzymes are proteins that have a specific shape that accommodates the molecule they are acting on called a substrate. The enzyme is not used or changed in the reaction, but races off from one substrate to another substrate molecule of the same kind, changing as many as 50,000 substrate molecules each minute. Since there are thousands of biochemical reactions necessary in the life of a cell, there are also thousands of different enzymes.

Enzyme EnzymeProductSubstrate

+ +

Catalase is an oxidative enzyme which catalyzes the reduction of hydrogen peroxide to pro-duce water and oxygen. This is a common reaction in metabolism.


Catalase

O2

2 H2O2

2 H2O2

CatalaseCatalase

2 H2O2 H2O

+Catalase Catalase-H2O2complex

2 H2O2 + +Catalase 2 H2O O2

You will now conduct an experiment to investigate enzyme function. You will test the enzyme catalase that converts hydrogen peroxide (H2O2) into water and oxygen. The source of the cata-lase for this experiment will be potatoes. You will be testing the effect of elevated temperature and low pH on enzyme function. Additionally, you will test the effect of increasing the quan-tity of catalase.



Obtain four clean, dry test tubes. Label the test tubes 1 through 4 with a wax pencil. Obtain a potato core long enough to be cut into four pieces, each 1 cm in length. If your core is not long enough, take a second core (with the same borer). Remove any skin and rinse each core clean. Place one core into the beaker at the instruction station. This core will be cooked in the microwave for two minutes. Finely chop the second core into small pieces, being careful not to lose any. Place the third core into the beaker of acid located on your lab bench for at least 10 minutes. Be careful! Always handle the acid-soaked potato core with forceps because the acid can burn your skin. Leave the fourth potato core unaltered.

Assemble four test tubes as follows:

Tube 1: 4 ml H2O2 + unaltered potato core

Tube 2: 4 ml H2O2 + microwaved potato core

Tube 3: 4 ml H2O2 + chopped potato core

Tube 4: 4 ml H2O2 + acid-soaked potato core

The liquid will begin to bubble as soon as the potato core is added. Mark the highest point the bubbles reach on the side of each test tube using a wax pencil. Measure the distance between the top of the liquid to the max-bubble line. Record your data in Table 3.1.

Measure the sample from the top of the liquid line to the top of the bubbles.

Table 3.1. Amount of bubbles produced when H2O2 is exposed to catalase under differing conditions.

Tube Number Potato Core Height of Bubbles (cm)

1 Unaltered

2 Microwaved

3 Chopped

4 Acid-soaked

Which treatment resulted in the greatest amount of bubbles? Why?

Which treatment produced the least amount of bubbles? Why?



3 How did lowering the pH affect the reaction? Why?

ACTIVITY 6

Nucleic Acids

NucleotidesNucleotides are important building blocks of nucleic acids (DNA and RNA), some coenzymes, and ATP. All nucleotides are composed of a nitrogenous base, pentose sugar, and a phosphate group.

DNA, deoxyribonucleic acid, is composed of nucleotides containing one of four nitrogenous bases: adenine, cytosine, thymine, and guanine. RNA, ribonucleic acid, does not contain thy-mine. Instead, RNA contains the nitrogenous base uracil.

Of the nitrogenous bases in nucleic acids, three are classified as pyrimidines and two are clas-sified as purines. The pyrimidines have a single ring structure and include cytosine, thymine, and uracil. The purines have a double ring structure and include adenine and guanine. In the double-helix form, DNA always has a purine nucleotide bound to a pyrimidine nucleotide by hydrogen bonds. As a result, the helix has a uniform diameter (2 nm).

Besides the differences in nitrogenous bases, the pentose sugar differs in DNA and RNA. RNA contains the pentose sugar ribose while DNA contains the pentose sugar deoxyribose.

When one phosphate group is added to AMP (adenosine monophosphate), adenosine diphos-phate (ADP) is formed. When the next phosphate group is added, adenosine triphosphate (ATP) is formed. Structural formulas of these molecules are shown below.

ATP is the energy currency of the cell. When the phosphate group is removed from ATP to make ADP, a tremendous amount of energy is released and the cell can use this energy to do work.

N

H

H

HH

HNC

N

N

N CC

CC

H

OHOH

CH2OHO

OH

O

OH

O

OH

O

OPOPOP

ATPADP

AMP



Deoxyribose

HOCH2

H

H

HH H

O OH

OH

Uracil

N

N

O

HH

OH

H

HN

H

H

H

NC

N

N

N C

O

CC

C

HH

Guanine (G)

N

H

H

H

HH

HNC

N

N

N CC

CC

H

Adenine (A)

HH

ON

N

C

H

H

NC

C

C

H

Cytosine (C)

H3C H

O

O

NC

H

NC

C

C

H

Thymine (T)

CH3

N

HCytosineThymine GuanineAdenine

N

N

N

N

N H

H

H

N

N

NN

N

N

N H

H

O

O

ON

NH

H

O

What Do You Think?What are nucleotides composed of?

What are three molecules composed of nucleotides?

What are three differences between DNA and RNA?

Why is the pentose sugar in DNA called deoxyribose?

Which nucleotides are considered purines? Which are considered pyrimidines?



3 ACTIVITY 7Testing for Biological Molecules (if time permits)You will now test a variety of unknown products to determine which biological molecules they contain. Using snack food and beverages you brought to lab (or those provided by your lab instructor), you will test for the presence of glucose, starch, and protein.

Testing for ProteinPut food item into blender with 50 ml of water. Blend the food item until it is very smooth. Dip a Combistix strip into the beaker containing the food item slurry. Rinse or wipe the residue off the strip. Compare the color on the strip to the color chart provided with the strip to estimate the amount of protein in the food item. Record your results in Table 3.2.

Testing for StarchUsing the same slurry, pour 3 ml of slurry into a test tube. Add several drops of iodine to the test tube. If starch is present, the iodine will stain the starch dark blue/black. If the solu-tion does not become very dark blue/black, there is no starch present. Record your results in Table 3.2.

Testing for GlucoseUsing the slurry prepared for the protein test, pour 3 ml of slurry into a test tube. Add 2 drops of Benedict’s solution. Place the test tube into a hot water bath for 15–20 minutes. If the solu-tion becomes a yellow-orange color, there is glucose present. If the solution does not change in color, there is no glucose present. It is important to dispose of the material in a Benedict’s test properly. It cannot go down the drain. Please dispose of your Benedict’s test material by pour-ing it into the flask marked “Benedict’s Waste.”

Table 3.2. Composition of food items brought to lab.

Food Item Protein Test Starch Test Glucose Test



Amino Acid Structures


Aspartic acid(Asp)I pH = 3.0

NH2

CH2CH

OH

O

C

HO

O

C

NH2

CH2CH

CH3

CH3

CH

HO

O

C

NH2

NH

CH2CH2

CH2

CH

CH3

CH CH2 CH3

HO

O

C

CH

HO

O

C

NH2

CH

CH3

CH3

CH

HO

O

C

NH2

CH3CH

HO

O

C

NH2

HCH

HO

O

C

NH2

CH2CH

OHHO

OO

CCH2C

NH2

CH2CH

NH2HO

OO

CCH2C

NH2

CH2CH

HO

O

CH2 CH2 CH2 NH2C

NH2

NH2

NH

CH2CH

HO

O

CH2 CH2 NH CC

NH2

CH2CH

NH2HO

OO

CC

NH2

CH2CH

CHHO

CH

CH

CHO

C CHC

NH2

CH2CH

HO

O

SHC

NH2

CH2CH

HO

O

CH2 CH3SC

NH2

CH2CH

HO

O

OHC

Glutamic acid(Glu)I pH = 3.2

Cysteine(Cys)I pH = 5.0

Asparagine(Asn)I pH = 5.4

Phenylalanine(Phe)I pH = 5.5

Glutamine(Gln)I pH = 5.7

Serine(Ser)I pH = 5.7

Tyrosine(Tyr)I pH = 5.7

Methionine(Met)I pH = 5.8

Tryptophan(Trp)I pH = 5.9

Alanine(Ala)I pH = 6.0

Glycine(Gly)I pH = 6.0

Leucine(Leu)I pH = 6.0

Valine(Val)I pH = 6.0

Isoleucine(Ilu)I pH = 6.1

Proline(Pro)I pH = 6.3

Threonine(Thr)I pH = 6.5

Histidine(His)I pH = 7.6

Lysine(Lys)I pH = 9.8

Arginine(Arg)I pH = 10.8

NH2

CH2CH

CHHO

CH

CH

CHO

C OHCC

NH2

CH2CH

CHHO

CHC CHO

C

N

C CH

HC

C

H

NH2

CH

OH

CH CH3

NH2

CH CH2

HO

O

C

HN

CHN

CHC

HO

O

C



3

PE

RIO

DIC

TA

BLE

OF T

HE

ELE

ME

NT

SH

1.00

8Hydrogen

1 Li 6.94

Lithium

3 Na

22.9

9Sodium

11 K39

.10

Potassium

19 Rb

85.4

7Rubidium

37 Cs

132.

91Cesium

55 Fr

Francium

87

B10

.81

Boron

5 Al

26.9

8Alum

inum

13 Ga

69.7

2Gallium

31 In11

4.82

Indium

49 Tl

204.

38Thallium

81 Nh

Nihonium

113

C 12.0

1Carbon6 Si

28.0

9Silicon

14 Ge

72.6

3Germ

anium

32 Sn

118.

71Tin

50 Pb

207.

2Lead82

Flerovium

114

N14

.01

Nitrogen

7 P30

.97

Phosphorus

15 As

74.9

2Arsenic

33 Sb

121.

76Antim

ony

51 Bi

208.

98Bism

uth

83 Mc

Moscovium

115

O 16.0

0Oxygen

8 S32

.06

Sulfur

16 Se

78.9

7Selenium

34 Te 127.

60Tellurium

52 Po

Polonium

84

Liverm

orium

116

F19

.00

Fluorine

9 Cl

35.4

5Chlorine

17

79.9

0Brom

ine

35 I12

6.90

Iodine

53 At

Astatine

85 TsTennessine

117

Ne

20.1

8Neon10He

4.00

Helium

2 Ar

39.9

5Argon

18 Kr

83.8

0Krypton

36 Xe 131.

29Xenon

54 Rn

Radon

86 Og

Oganesson

118

Be

9.01

Beryllium

4

Mg

24.3

1Magnesium

12 Ca

40.0

8Calcium

20 Sr

87.6

2Strontium

38 Ba

137.

33Barium

56 Ra

Radium

88

Sc

44.9

6Scandium

21 Y88

.91

Yttrium

39

57–7

1

89–1

03

Ti

47.8

7Titanium

22 Zr

91.2

2Zirconium

40 Hf

178.

49Hafnium

72

Rutherfordium

104

V50

.94

Vanadium

23 Nb

92.9

1Niobium

41 Ta

180.

95Tantalum

73

Dubnium

105

Cr

52.0

0Chromium

24 Mo

95.9

5Molybdenum

42 W18

3.84

Tungsten

74

Seaborgium

106

Mn

54.9

4Manganese

25 TcTechnetium

43 Re

186.

21Rhenium

75

Bohrium

107

Fe

55.8

5Iron

26 Ru

101.

07Ruthenium

44 Os

190.

23Osmium

76

Hassium

108

Co

58.9

3Cobalt

27 Rh

102.

91Rhodium

45 Ir19

2.22

Iridium

77

Meitnerium

109

Ni

58.6

9Nickel

28 Pd

106.

42Palladium

46 Pt

195.

08Platinum

78

Darm

stadtium

110

Cu

63.5

5Copper

29 Ag

107.

87Silver

47 Au

196.

97Gold

79

Roentgenium

111

Zn

65.3

8Zinc30

La 138.

91Lanthanum

57

Ce

140.

12Cerium

58

Pr

140.

91Praseodymium

59

Nd

144.

24Ne

odym

ium

60

Pm

Prom

ethium

61

Sm

150.

36Samarium

62

Eu

151.

96Europium

63

Gd

157.

25Gadolinium

64

Tb

158.

93Terbium

65

Dy

162.

50Dysprosium

66

Ho

164.

93Holmium

67

Er

167.

26Erbium

68

Tm

168.

93Thulium

69

Yb

173.

05Ytterbium

70

Lu 174.

97Lutetium

71

Ac

Actinium

89

Th

232.

04Thorium

90

Pa

231.

04Protactinium

91

U23

8.03

Uranium

92

Np

Neptunium

93

Pu

Plutonium

94

Am

Americium

95

Cm

Curium

96

Bk

Berkelium

97

Cf

Californium

98

Es

Einsteinium

99

Fm

Ferm

ium

100

Md

Mendelevium

101

No

Nobelium

102

Lr

Lawrencium

103

Cd

112.

41Cadm

ium

48 Hg

Br

200.

59Mercury

80

Copernicium

112

1 IA

GR

OU

P

PERIOD

2 IIA3 IIIB

4 IVB

5 VB

6 VIB

7V

IIB8

9V

IIIB

1011 IB

12 IIB13 III

A14 IV

A15 VA

16 VIA

17 VIIA

18 VIII

A

1 2 3 4 5 6 7

So

lidLiquid

Gas

Sta

te a

t st

and

ard

tem

per

atu

rean

d p

ress

ure

(0 °

C a

nd 1

atm

):A

tom

ic n

umb

er

Key

:

Ele

men

t sy

mb

olE

lem

ent

nam

eS

tand

ard

ato

mic

wei

ght

Na

22.9

9Sodium

11

FlLv

Rf

Db

Sg

Bh

Hs

Mt

Ds

Rg

RRCn

Unknown

(No

dat

a gi

ven

for

elem

ents

w

ithou

t st

able

nuc

lides

.)

ALKA

LIM

ETAL

S

NON

-MET

ALS

METALLOIDS

ALKALINE EARTH METALS

TRA

NSI

TIO

N M

ETA

LS

HALO

GENS

P-BL

OCK

MET

ALS

NOBLE GASES

LANTHANOIDS ACTINOIDS

RARE EARTH METALS

Not

es: “

Cae

sium

” an

d “

alum

iniu

m”

are

the

inte

rnat

iona

lly r

ecog

nize

d s

pel

lings

for

“ces

ium

” an

d “

alum

inum

.” A

n at

omic

wei

ght

(rela

tive

atom

ic m

ass)

of a

n el

emen

t fro

m a

sp

ecifi

ed s

ourc

e is

the

ratio

of t

he a

vera

ge m

ass

per

ato

m o

f the

ele

men

t to

1/12

of t

he m

ass

of a

n at

om o

f 12 C

(IU

PA

C).

Sou

rces

: IU

PA

C p

erio

dic

tab

le 2

8 N

ovem

ber

201

6; P

ure

and

Ap

plie

d C

hem

istr

y 88

, No.

3 (2

016)

.

REV 8/2017 © Hayden-McNeil, LLC


Documents

BIO 1 - websites.rcc.eduwebsites.rcc.edu/tayyar/files/2019/12/White-1186-5-F19_Watermarked.pdf2 EXERCISE 1 The Scientific Method 1 2. Always carry your microscope with two hands. One