Transcript
Page 1: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Unit 1

Scientific Theory and Biomolecules

Page 2: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Laboratory Safety Skills• It is YOUR responsibility to protect yourself and

other students by conducting yourself in a safe manner while in the laboratory.

• It is also your responsibility to read the Flinn safety contract, sign it, and have it signed by a parent or guardian.

• You will NOT be allowed to participate in labs until you return your signed safety contract AND pass the laboratory safety quiz.

Page 3: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

General Guidelines of Laboratory Safety• Only perform experiments specifically assigned by your teacher.• Familiarize yourself with the investigation and all safety precautions before

entering the lab.• Before beginning work, tie back hair, roll up loose sleeves, and put on any required

personal protective equipment.• Always wear a lab apron and safety goggles.• No contact lenses allowed in the lab. • Know the location of all safety and emergency equipment used in the laboratory.• Immediately report any accident, incident, or hazard—no matter how trivial—to

your teacher.• In case of fire, alert your teacher and leave the lab!• Do not have or consume food or drink in the lab.• Do not fool around in the lab.• Do not apply cosmetics in the lab.• Keep your work area neat and uncluttered.• Clean your work area at the conclusion of each lab period as directed by your

teacher. • Wash your hands with soap and hot water after each lab period. Pg. 1024

Page 4: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Safety Symbols

Page 5: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Safety Symbols

Page 6: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Stages of Scientific Investigations

• Collecting Observations– Observation is the basis of scientific research. – Observation is the act of noting or perceiving objects or events

using the senses.• Asking Questions• Forming Hypotheses and Making Predictions

– Hypothesis: an explanation that might be true—a statement that can be tested by additional observations or experimentation.

– Prediction: the expected outcome of a test, assuming the hypothesis is correct.

• Viewing Conclusions in Context

Page 7: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Stages of Scientific Investigations

• Confirming Predictions– Experiment: a planned procedure to test a hypothesis.– Control group: a group in an experiment that receives

not experimental treatment.– Independent Variable: the factor that is changed in an

experiment.– Dependent Variable: the factor that is measured in an

experiment. • Drawing Conclusions• Viewing Conclusions in Context

Page 8: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Scientific Explanations• Scientists build theories from

questions, predictions, hypotheses, and the findings of their experiments. When related hypotheses consistently explain scientific events, a theory is formed.

• Theory: a set of related hypotheses that have been tested and confirmed many times by many scientists.– Unites and explains a broad range

of observations.

Page 9: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Chemistry of Life: Nature of Matter, Water and Solutions

Ch. 2.1, 2.2

Page 10: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Atoms• Chemistry will help you learn

about biology because organisms are chemical machines!

• Atom: smallest unit of matter that cannot be broken down by chemical means. Made of:– Protons: positive, in nucleus – Neutrons: neutral, in nucleus– Electrons: negative, in electron

cloud

Page 11: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Elements and Chemical Bonding• Atoms can join with other atoms to

form stable substances. The force that joins atoms is a chemical bond.

• Element: a pure substance made of only one type of atom– Differ in the number of protons in the

nucleus• Compound: a substance made of the

joined atoms of two or more different elements in known proportions– Represented by chemical formulas

Page 12: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Covalent Bonds• Covalent Bonds: form when two or more atoms

share electrons to form a molecule• Molecule: A group of atoms held together by

covalent bonds

Page 13: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Ionic Bonds• Sometimes atoms or molecules gain or lose electrons.– Ion: An atom/molecule that has gained or lost an electron

• Ionic Bonds: a bond formed when ions of opposite charges are attracted– Found in table salt (Sodium Chloride, NaCl)

Page 14: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Hydrogen Bonds• Hydrogen Bonds: Bonds

based on polarity of molecules which causes chemical attraction.– Bonds with an unequal

distribution of electrical charge are called polar molecules.

– Water molecules are polar and often form hydrogen bonds.

– The different charges in each molecule makes the molecules attract each other.

Page 15: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Water in Living Things, Storage of Energy

• 70% of your body is made up of water• Water absorbs heat slowly• Water retains energy well• Water absorbs heat more slowly and retains this

energy longer than other substances, helping us maintain our body temperature.

• Controlling body temperature is important part of homeostasis. – Homeostasis: the maintenance of a constant internal

state in a changing environment.

Page 16: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Cohesion and Adhesion• Cohesion: an attraction between

substances of the same kind.– Molecules of water are stuck

together because of the hydrogen bonds between water molecules.• This is why water forms drops!

• Adhesion: an attraction between different substances.– Water is attracted to other polar

substances.• Capillary action is the process in

which water molecules move upward through a narrow tube because the water sticks to the wall of the tube.

Page 17: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Polarity• The polarity of water enables many substances to dissolve in water.

– Solution: a mixture in which one or more substances are evenly distributed in another substance.

– Non-polar substances such as oil do not dissolve well.• Ionic compounds and polar molecules dissolve best in water, because

they are charged like the water.• When ionic compounds are dissolved in water, the ions become

surrounded by polar water molecules.

Page 18: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Acids and Bases• While the bonds in water molecules are strong, sometimes these bonds

break, forming a hydrogen ion (H+) and a hydroxide ion (OH-).H2O H+ + OH-

• Acids: compounds that form hydrogen ions when dissolved in water and have a pH below 7

• Bases: compounds that reduce the concentration of hydrogen ions in a solution and have a pH above 7

• pH: a value used to express the acidity or alkalinity of a solution, this is the pH scale:

Page 19: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Chemistry of Life: Chemistry of Cells

Ch. 2.3

Page 20: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Organic Compounds• Most non-water matter in your

body is made of organic compounds

• Organic compounds contain carbon atoms that are covalently bonded to other elements such as H (Hydrogen), O (Oxygen) and other C (Carbon) atoms– Biomolecules: organic compounds

that are important in the structure and function of living organisms. There are 4 biomolecules you need to know for this class: • Carbohydrates, Lipids, Proteins, and

Nucleic Acids

Page 21: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Dehydration Synthesis and Hydrolysis • Dehydration Synthesis: A chemical reaction that

builds up molecules by losing water molecules. • Hydrolysis: The process of splitting a compound

into fragments with the addition of water; a kind of reaction that is used to break down polymers into simpler units, e.g. starch into glucose.

• So, Dehydration Synthesis LOSES water, while Hydrolysis ADDS water! Which process is represented by the image below?:

Page 22: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Carbohydrates• Organic compounds made of carbon, hydrogen and oxygen

atoms in the proportion of 1:2:1• Carbohydrates are basically made of carbon and water!• Carbohydrates are built from single sugars called

monosaccharides• Polysaccharides are chains or three or more monosaccharides.• Polysaccharides are macromolecules

Page 23: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Lipids•Lipids are nonpolar molecules that are not soluble or are mostly insoluble in water•Made of fatty acids attached to a glycerol• Include fats, phospholipids,

steroids, and waxes. •Important in cell membranes•Fats store energy

Page 24: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Proteins• A large molecule formed by

linked smaller molecules called amino acids– Amino acids contain Nitrogen, an

important element for life!

• Amino acids are the building blocks of proteins.

• 20 different amino acids are found in proteins

• Some proteins are enzymes and promote chemical reactions

Page 25: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Nucleic Acids• All of your cells contain nucleic acids– DNA and RNA are two common nucleic acids

• Nucleic acids are long chains of smaller molecules called nucleotides

• A nucleotide as three parts: a sugar, a base, and a phosphate group

Page 26: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Energy and Chemical Reactions

Ch. 2.4

Page 27: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

ATP• ATP Stands for Adenosine triphosphate• A single nucleotide with two extra energy storing phosphate

groups (so why is it called ATP?)• Cells need a steady supply of ATP to function

http://biochemisms.com/tag/atp/

Page 28: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Energy for Life Processes• Energy is the ability to move or change matter.• Exists in many forms: light, heat, chemical, mechanical,

electrical; can be converted to other forms.• Energy can be stored or released by chemical reactions.• Chemical reactions are summarized by chemical

equations, written: Reactants Products NaCl Na+ + Cl-

Page 29: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Energy in Chemical Reactions• In a chemical reaction, energy is

absorbed or released when chemical bonds are broken and new ones are formed. – Some chemical reactions release energy– Other chemical reactions absorb energy

• Metabolism: all of the chemical reactions that occur within an organism. – Most of our energy comes from the food

we eat and digest! – When we digest food, chemical reactions

convert the chemical energy in food molecules into energy our cells can use.

Page 30: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Activation Energy• Activation energy: the energy needed to start a

chemical reaction– Example: a big rock rolling down the hill—to make it roll,

you must first push it. The activation energy is a “push” for chemical reactions!

• Enzymes are substances (mostly proteins) that increase the speed of chemical reactions (catalysts)

Page 31: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Enzymes• Most biochemical reactions (reactions that occur in

cells) require activation energy to begin. • Chemical reactions can occur quickly and at the low

temperature of our body because of enzymes.• Enzymes: substances that increase the speed of

chemical reactions. Most enzymes are proteins. • Enzymes help organisms maintain homeostasis.

Page 32: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Enzyme Specificity • Substrate: a substance on which an enzyme acts during a

chemical reaction.– Enzymes act ONLY on specific substrates.– For example, amylase, an enzyme in your saliva, assists in the

breakdown of starch to glucose in your food.• Enzymes often end with the letters “ase” so we can figure out that

“amylase” is an enzyme even if we’ve never heard of it before!

• An enzyme’s activity is determined by the shape of the enzyme.

Page 33: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Enzyme Specificity • Typically, an enzyme is a large protein with one or

more deep folds on the surface.• Active sites: pockets in the folds on enzyme surfaces.– The substrate of the reaction fits into the active site.– An enzyme acts only on a specific substance because only

that substrate fits into the active site.

Page 34: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Inhibition: Competitive and Non-Competitive

Enzyme function can be inhibited (restrained or checked)in two main ways:

• Competitive Inhibition: inhibitor that fills the active site of an enzyme and stops the normal substrate from binding (biology-online.org).

• Non-Competitive Inhibition: Enzyme inhibition in which the inhibiting substance does not compete with the normal substrate for the active site on the enzyme but inhibits reaction by combining with the enzyme-substrate complex after the complex is formed (medical-dictionary.thefreedictionary.com)

Page 35: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Factors in Enzyme Activity• Enzymes operate most efficiently within a certain

range of temperatures or in a certain pH.• Temperatures outside the normal range can break

of strengthen some bonds between amino acidsin the enzyme (usually made of protein), changing the shape.– If the shape is changed, the active site may also change

and the substrate will be unable to bind. • pH also impacts enzyme activity. A pH that is too

low (acidic) or too high (alkaline) can also break bonds between amino acids, changing the shape of the protein.

Page 36: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Digestion

Ch. 39.2

Page 37: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Breaking Down Food• Before your body

can use the nutrients in food you eat, the large food molecules must be broken down.

• Digestion: the process of breaking down food into molecules the body can use.

Page 38: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Starting Digestion• Digestion of food begins in

your mouth.• Teeth rip and chew food and

mix food in with saliva.• Saliva contains amylases.• Amylases: enzymes that

begin the breakdown of carbohydrates such as starch, into monosaccharides (single sugars).

• Food then passes through the pharynx into the esophagus.

Page 39: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

The Esophagus• Esophagus: a long tube that

connects the mouth to the stomach. – No digestion takes place in the

esophagus. • Food is moved through the

esophagus through peristalsis. – Peristalsis: successive rhythmic

waves of smooth muscle contractions in the esophagus that moves the food toward the stomach.

Page 40: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

The Stomach• The stomach is a saclike organ

that stores food temporarily and mechanically breaking down food and chemically breaking down proteins.

• When food enters the stomach, it secretes gastric juice, a mixture of hydrochloric acid and pepsin.– Pepsin: a digestive enzyme that

breaks protein strands into chains of amino acids.

Page 41: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

The Small Intestine• Food passes into the small intestine is where carbohydrates are

broken down into monosaccharides, proteins into amino acids, and lipids into fatty acids and glycerol.

• Fats are digested by pancreatic enzymes called lipases, but are first treated with bile which emulsifies the fats (turns them into little drops).

• Absorption of nutrients occurs in the small intestine through the lining of the small intestine on projections called villi.

Page 42: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

The Large Intestine• Components of food that are

not for energy production are considered wastes.

• Wastes move into the large intestine, also called the Colon. No digestion takes place in the colon.

• Most of colon’s contents are dead cells, mucus, digestive secretions, bacteria, and yeast.

• Balancing water absorption is an important function of the colon.

Page 43: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

The Liver’s Role in Digestion and Metabolism• The liver plays several roles in human digestion and

metabolism even though food never enters the liver.• The Liver’s Role in Digestion– Secretes bile, which aids in the emulsification of fat and

promotes the absorption of fatty acids and fat soluble vitamins A, D, E, and K.

• The Liver’s Role in Metabolism– The liver stabilizes blood sugar by converting extra sugar to

glycogen for storage. The liver then breaks down the glycogen when needed.

– The liver also modifies amino acids.– Fat-soluble vitamins and iron are stored in the liver. – The liver monitors the production of cholesterol and detoxifies

poisons. If the liver cannot make something non-toxic, it stores it.

Page 44: Unit 1 Scientific Theory and Biomolecules. Laboratory Safety Skills It is YOUR responsibility to protect yourself and other students by conducting yourself

Digestive Enzymes