Honors Biology

Module 5: The Chemistry of Life

October 17, 2013

Class Challenge

Questions from Module 4:

1. Reading,

2. OYO’s,

3. Study Guide or

4. Module 4 test.

Quiz question 1-3

Name the 3 ways that molds can reproduce and draw a picture of each.

1. They can asexually reproduce when a stolon lengthens and forms a new filament.

2. They can asexually reproduce with the production of sporangia (from aerial hyphae)

3. When hyphae fuse together they sexually reproduce to form a zygospore that can then mature into another fungus.

Let’s Review

In Module 1 we have learned to identify what is life:

1. All life forms contain DNA

2. All live forms have a method by which they can extract energy from their surroundings and convert it into energy that sustains them.

3. All life forms can sense change in their surroundings and respond to those changes.

4. All life forms reproduce.

Module 2

Kingdom Monera: 1. Prokaryotic cells2. Bacteria3. Microscopic4. Coccus bacteria, bacillus bacteria,

spirillum bacteria.

5. Remember Experiment Pond Life

Module 3

Kingdom Protista1. Microscopic 2. Eukaryotic cells3. Diatoms, Dinoflagellates, Algae4. Amoeba, paramecium, euglena, volvox

5. Again, Pond life a week later. More things grew….!

Module 4

Kingdom Fungi

1. Mushrooms

2. Yeasts

3. Molds to include slime molds

Module 5: The Chemistry of Life

You have learned a lot about the organisms within these kingdoms, hopefully you have begun to develop an understanding for the complexity and grandeur of God’s creation.

In Module 5 you will be introduced to the study of chemistry. You will begin to understand the chemistry that helps make life possible.

Atoms:The Basic Building Blocks of Matter

Matter: Anything that has Mass and takes up space.

Mass: if something has mass, it will also have weight.

Cells

Are the basic building blocks of life. What makes up the cell is the first thing used to start the process of classifying it.

Organisms made up of prokaryotic cells belong in Kingdom Monera.

Organisms made up of eukaryotic cells belong in one of the other four kingdoms.

Atoms

Just as cells are the basic building blocks of life,

ATOMS are the basic building blocks of

matter.

Everything from the tiniest speck of dust to the biggest mountain in the world is made up of atoms.

The Size of Atoms

The dot of an “I” on a page in a book contains approximately one billion

(1,000,000,000) atoms!

They are simply too small to see. Scientists using the most powerful microscopes in the world cannot see them. But performing detailed experiments, provided them with ample evidence for their existence.

The Existence of atoms has become the foundational principle that guides our understanding of chemistry.

There are even small things called protons, neutrons and electrons.

Figure 5.1

Figure 5.1 shows a simplified schematic of a Helium atom.

Notice that the neutrons and protons clump together in the center of the atom, which is called the nucleus. (In a cell, “nucleus” is also used to identify the organelle that holds the DNA in a eukaryotic cell)

In Atoms, nucleus refers to the center of the atom where the protons and neutrons clump together.

Whirling around the nucleus, are the electrons.

If we cannot see Atoms how do we know what they look like?

Scientists have done many experiments designed to help us understand the structure of the atom. Figure 5.1 is consistent with most of those experiments.

Scientists call this a good model.

A Model is an explanation or representation of something that cannot be seen.

Just because a model is consistent with experiments does not necessarily mean that it is an accurate representation.

At a later date, scientists may come up with experiments that contradict the model, or someone else might come up with a different model that is also consistent with all of the experiments done.

Figure 5.1Is not accurate. Experiments clearly show

this model called the “Bohr Model” to be in error.

The new model of the atom, called the “quantum mechanical model,” is currently the model believed by most scientists. It is very complex and in order to understand it you have to have several years of math beyond calculus.

The Bohr Model of an Atom

Will help you understand the quantum mechanical model when you get to it.

Protons and neutrons are packed into the nucleus, which is the center of the atom.

Electrons whirl around the nucleus in a circular orbit.

The number of protons, neutrons, and electrons in an atom determines all of the properties of that atom.

• Dr Wile’s DVD

Properties of an atom

Helium is a gas that is lighter than air. That is why a balloon filled with helium floats.

The fact that helium is a gas and the fact that it is lighter than air are both a result of the number of protons, electrons, and neutrons in the atom.

If you change the number of protons, electrons, and neutrons in an atom, you change its properties.

An atom that contains 6 protons, 6 neutrons, and 6 electrons is a type of carbon atom.

Carbon is not a gas; it is a solid. It is black and brittle. These properties (as well as all of the other properties of the atom) are once again the result of the number of protons, electrons, and neutrons in the atom.

No matter how many protons, electrons and neutrons make up an atom, there is one general principle that applies to them all.

All atoms have equal numbers of protons, and electrons.

If an atom has 3 protons then you know it will have 3 electrons.

Protons and Electrons each have electrical charges

Protons have Positive (+) charges and Electrons have Negative (-) charges.

Because there are a equal number of protons (+) and electrons (-) scientists say that the atoms are balanced and the total charge is zero.

Neutrons, have no electrical charge.

An Atom’s properties are determined by…

The number of electrons that it has.

Protons and neutrons are tucked away in the center of the atom (the nucleus).

Since the electrons orbit around the nucleus, they are, in effect what makes up the “outer layer” of the atom.

If two atoms were to come close to one another, their electrons would be the first things to interact. As a result, the electrons determine the vast majority of an atom’s properties.

All atoms have the same number of protons and electrons.

The number of electrons that determine an atom’s properties, since the number of protons is always equivalent to the number of electrons.

We could also say that the number of protons can be used to determine an atoms’s properties.

If two atoms have the same number of protons, they will have the same number of electrons. Even if the number of neutrons in the first atom is different from the number of neutrons in the second, the vast majority of the two atoms’ properties will be the same because they have the same number of electrons.

Elements

Are a collection of atoms that all have the same number of protons (regardless of their number of neutrons).

Some of the Biologically Important Elements. Table 5.1

Element Name Abbreviation

Carbon C

Hydrogen H

Oxygen O

Nitrogen N

Phosphorus P

Sulfur S

1. Atoms are made up of protons, neutron, and electrons.

2. No matter how many protons an atom has, it will have the same number of electrons.

3. When different atoms have the same number of protons (and electrons), they are said to belong to the same element, because they have the same basic properties.

4. To name an atom, we call it by the element to which it belongs, followed by the sum of its protons and neutrons.

When you see a name life Sulfur-32 (or S-32 or sometimes 32 S), you know that we are talking about a particular atom,

the one that has 16 protons (that is what makes it sulfur) and

16 neutrons (that’s how to get a 32 when you add the protons and neutrons together).

However,….

If you just see sulfur (or S), then you know that we are talking about an element, which probably contains more than one type of atom.

There are sever atoms that all have 16 protons and thus belong to the element Sulfur but have different numbers of neutrons.

The element to which an atom belongs, is the most important aspect of identifying an atom.

You will usually see jus the element (life Sulfur) instead of seeing a particular atom (Sulfur-32) when you study chemistry.

You always need to remember, that an element (such as Sulfur) is composed of many individual atoms (such as Sulfur-32, Sulfur-33, Sulfur-34, and Sulfur- 36).

Molecules

If there are only 116 known elements in God’s creation, you might only think that there are only 116 different types of matter.

After all matter is made up of atoms, and each element contains matter, ….right?

…….Wrong!!

Molecules

Atoms are the basic building blocks of matter. In order to provide the chemical diversity necessary for life, God designed atoms to link together much like the pieces of a jigsaw puzzle.

When atoms link together they form Molecules.

For example, carbon dioxide is a gas that humans (and many organisms) produce as a part of their metabolism.

This gas is formed when 1 carbon and 2 oxygens link together.

Chemical Abbreviation: CO2

Methane: CH4

Glucose: C6H12O6

The important thing to realize about molecules is that:

1. The properties of a molecule are determined by the type and number of atoms that link together, as well as the way that they link together.

2. The number of atoms that link together determine the properties of a molecule.

Dr Wile’s DVD

Changes in Matter

Physical Change: A change that affects the appearance but not the chemical makeup of a substance.

Physical changes are generally reversible; Sugar

Chemical Change: A change that alters the makeup of the elements or molecules of a substance.

Chemical changes are generally not reversible. Burning paper.

Physical Change and the Phases of Matter involving energy

Every substance is capable of attaining one of three forms:

SOLID add heat-- LIQUID-- add heat GAS

-take away -- take away

heat heat

Physical Change when one substance is dissolved in another

The result is a solution.

The substance being dissolved in the liquid is called a solute.

The liquid is called a solvent.

Diffusion

Is the random motion of molecules from an area of high concentration to an area of low concentration.

Concentration: A measurement of how much solute exists with a certain volume of solvent.

Figure 5.2

Semipermeable membrane: A membrane that allows some molecules to pass through but does not allow other molecules to pass through.

Osmosis: The tendency of a solvent to travel across a semipermeable membrane into areas of higher solute concentration.

Chemical Changep. 139

When methane and oxygen interact to make water and carbon dioxide

Reactants products

CH4 + O2 + H2O + CO2

CH4 + 2O2 2H2O + CO2

It is important to understand that when a chemical reaction occurs, the molecules on the lift side of the arrow are destroyed, and the molecules on the right side of the arrow are produced.

In the burning of methane, you start out with 1 methane molecule (CH4) and 2 Oxygen molecules. These molecules interact, exchanging atoms so that the methane and oxygen molecule are destroyed. In the process, 2 water molecules (H2O) and 1 Carbon dioxide Molecule (CO2) are made.

Photosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

6 Carbon Dioxide molecules interact with 6 water molecules. Once they interact, 1 glucose molecule and 6 oxygen molecules are formed.

What is missing?

You’ve learned that photosynthesis requires sunlight. Where is the sunlight in this equation? It is not there, but it is still necessary for photosynthesis to happen.

If we put a bunch of Carbon Dioxide and water in a container, they would not interact to form glucose and oxygen. In order for them to interact, the carbon dioxide and water molecules must be pushed together. This takes energy which the plant get from sunlight.

So we place this container out in the sun, it would not produce much glucose and only after a long, long time.

So how do plants speed up this process?1. The chemical reaction could be

performed at a higher temperature…but that would kill the autotrophs.

2. Autotrophs use a Catalyst.

Catalyst

Is a substance that alters the speed of a chemical reaction but is not used up in the process.

For most autotrophic organisms, the catalyst is chlorophyll.

The bottom line, our Creator created an incredibly complex system and there is no such thing as a simple life form.

Mr. Anderson

Atoms and Matter

http://youtu.be/njGz69B_pUg

Diffusion and Osmosis

http://www.youtube.com/watch?v=LeS2-6zHn6M&feature=share&list=PL0B4CED0AB112B993

Potato Experiment

Atoms and Molecules

Homework

1. Continue Reading Module 5 P. 142- 1562. OYO Questions: 5.1 – 5.133. Study Guide: a-l and 2-144. Finish labs : Potato and drawings of

molecules.5. Quiz: Know diffusion and osmosis6. Class Challenge:7. Notebook check next week through Module 4 Make sure your tests are completed and

graded.