Stahl Biology

Unit 2- The Chemistry of Life Notes

Learning Targets:1. Identify elements common to living things.2. Describe how ions work.3. Compare ionic and covalent bonds4. Recognize the importance of hydrogen bonding.5. Explain why many compounds dissolve in water.6. Compare acids and bases.7. Describe the bonding properties of carbon atoms8. Compare and understand the importance of the four macromolecules: carbohydrates,

lipids, proteins, and nucleic acids.9. Describe how bonds break and reform during chemical reactions10. Explain why and how chemical reactions release or absorb energy.11. Explain the effect of catalysts on activation energy.12. Describe and explain how enzymes regulate chemical reactions.

Unit Opener: Carnivorous plant= Venus flytrapLike other carnivores, the Venus flytrap eats animals to get

nutrients that it needs to make molecules such as proteins and nucleic acids. Other chemical compounds made by plant’s cells enable the Venus flytrap to digest the animals that it eats. These chemicals are similar to the chemicals that allow you to digest the food that you eat.

If plants can make their own food through photosynthesis, why would a plant species evolve a mechanism to capture and eat animals?

_______________________________________________________________________________________________________________

Venus flytraps grow in swampy areas that have nitrogen poor soil. These plants get the nitrogen they need for survival by trapping and digesting animals.

What is everything made up of?

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______________________________________________ ______________________________________________

Atoms are made up of:

___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________

Draw and Label the atom (A little review):

Atomic Mass=Atomic Number=

Elements

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________________________________________________________________________________________________________________

________________________________________________________________________________________________________________

________________________________________________________________________________________________________________

Atoms are made up of the same types of particles, so what makes one element different from another?

__________________________________________________________________________________________________________________________

How many protons does hydrogen have? Oxygen?

Energy Levels:

1. ______________________________________________________

______________________________________________________

2. ______________________________________________________

3. ______________________________________________________

4. ______________________________________________________

______________________________________________________

5. ______________________________________________________

6. ______________________________________________________

______________________________________________________

______________________________________________________

7. ______________________________________________________

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Why does your blood need iron?_____________________________________________________________

Why does your body need chromium? __________________________________________________________________________________________________________________________Compounds:

1. ____________________________________________________________________________________________________________

2. ____________________________________________________________________________________________________________

Ions:

1. Atom that has gained or lost one or more electrons.2.______________________________________________________________________________________________________________________________________________________________________________________3. Either positive or negative4. Atoms with few electrons= lose electrons and becomes more positive5.____________________________________________________________

NaCl Transfers electron from sodium atom to chlorine atom

________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________

________________________________________________________ ________________________________________________________________ Opposites attract (+ / -)

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What determines whether an atom becomes a positive ion or a negative ion? _______________________________________________________________________________________________________________________________________________________________________________________

Molecule: __________________________________________________________________________________________________________________________

Covalent Bonds

__________________________________________________________ ________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________

CO2 Example

_______________________________________________________________________________________________________________________________________________________________________________________

Properties of Water!!!!!Waters unique properties allow life to exist on

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Polar Nonpolar

Earth.

They both tend to remain separate that is why they say, “oil and water don’t mix. “

Life depends on hydrogen bonds

________________________________________________________________________________________________________________________________________________________________________

________________________________________________________________________________________________________________________________________________________________________

________________________________________________________________________________________________________________

________________________________________________________________________________________________________________

Properties of Hydrogen bonds

Weakest of the bonds

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High specific heat= water resists changes in temperature; therefore water must absorb more heat energy to increase temperature.

*Very important with cells because our cells release a lot of heat and water absorbs that heat which allows us to regulate cell temperatures. Cohesion-> __________________________________________________________________________________________________________________________

*Makes water molecules stick together.*Ex- beads on a car when it is washed*Spider walking on top of the water.

Adhesion-> __________________________________________________________________________________________________________________________

*Water molecules stick to other things.*Ex- upward curve of the surface of the

water-> graduated cylinder*Ex- plants transport water up their

roots to their leaves.

Many compounds dissolve in water – UNIVERSAL SOLVENT Molecules and ions can’t take part in chemical processes inside cells unless they dissolve in water. Materials such as sugar and oxygen cannot be transported from one part of an organism to another unless they are dissolved in blood, plant sap, or water based fluids.

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Solution= __________________________________________________________________________________________________________________________

Solvent Solute

Solubility: ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________

Your plasma (liquid part of your blood) is 95% water. Which is the solvent and solute?

Water= ______________ Dissolved proteins, platelets, minerals, hormones= _____________

Why do the solutes such as proteins and sugars dissolve in the water of blood plasma?__________________________________________________________________________________________________________________________

Let’s Review a little!!!!! Questions????1.

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2.3.4.5.6.

Sum it up! Properties of Water:1. Hydrogen Bonding- strong cohesion (insects walking on water)2. Capillary Action- water moves upward (Roots to leaves)3. Strong Adhesion- attraction between two unlike substances4. Universal Solvent- dissolves everything5. High Specific Heat- cools / heats up slowly to allow temperatures in

organisms to maintain homeostasis6. Expands when freezes making it less dense

Acids and Bases

Acids Bases

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How is Ph regulated in our bodies?

1. __________________________________________________________________________________________________________________________________________________________________

2. __________________________________________________________________________________________________________________________________________________________________

3. __________________________________________________________________________________________________________________________________________________________________

Carbon Based Molecules

Carbons unique bonding properties

1. __________________________________________________________________________________________________________________________________________________________________

2. __________________________________________________________________________________________________________________________________________________________________

3. __________________________________________________________________________________________________________________________________________________________________

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Carbon Chains and Rings- three fundamental features

Draw each one!

Straight Chain Branched Chain Ring

Monomer / Polymer

Polymer= __________________________________________________________________________________________________________________________Monomer=____________________________________________________

Draw the picture and label

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Four Major Carbon Based Molecules / Macromolecules1.2.3.4.

Carbohydrates

________________________________________________________ ___ ________________________________________________________ ___ ________________________________________________________ ___ ________________________________________________________ ________________________________________________________________

Monosaccharides: ________________________________________________________ ________________________________________________________ Draw the molecule

Disaccharides ________________________________________________________ ________________________________________________________

________________________________________________________ Ex- Sucrose= common table sugar (made from glucose and fructose) Ex- Lactose= milk sugar (made from glucose and galactose)

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Polysaccharides ________________________________________________________

________________________________________________________ ________________________________________________________ Ex- starch and glycogen -> energy storage in plants and animals Ex- Cellulose- cell walls in plants

LIPIDS

Non-polar molecules because they are insoluble in water (they don’t dissolve) _____________________________________________________________________________________________________________________________________________________________________________________Function-_______________________________________________________________________________________________________________________________________________________________________________________Monomer=_______________________________Polymer=_________________________________

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3 Main Lipids:1. Fats or Triglycerides -

________________________________________________________________________________________________________________

2. A. Saturated fatty acids= held together by a single covalent bond and is solid at room temperature.

i. Has the maximum number of hydrogen atoms possible B. Unsaturated fatty acids= one or more double bonds between the carbon atoms.

-Not saturated with hydrogen atoms

C. Polyunsaturated = __________________________________________________________________________________________________________________________

3. Phospholipids- ___________________________________________________

___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________

Proteins Most varied- a part of everything from moving your leg to digesting

your pizza. Protein is the

__________________________________________________________________________________________________________________________

Amino acids are referred to as the __________________________________________________________________________________________________________________________

- We use 20 different amino acids to build proteins in our bodies.

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- Your body makes 12 and the others need to be ingested through meat, beans, and nuts.

- All have similar structures: hydrogen atom, an amino group (NH2), and a carboxyl group (COOH).

_________________________________________________________________________________________________________________________________________________________

___________________________________________________ ___________________________________________________ ___________________________________________________

______________________________________________________________________________________________________

Draw the polypeptide chain and label. - Held together by covalent bonds called peptide bonds. The bonds form between the amino group of one amino acid and the carboxyl group of another amino acid.

Polypeptide forms between two amino acids They are a single chain of three or more amino acids linked together

by peptide bonds.

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Functions of Proteins

1. Catalyzing Enzymes-________________________________________________________

i. ______________________________________________ii. ______________________________________________

______________________________________________iii. ______________________________________________iv. ______________________________________________v. ______________________________________________

______________________________________________

2. Defensive Proteins- ________________________________________________________________________________________________________________

i. Ex-____________________________________________

ii. Ex-____________________________________________

3. Storage Proteins- ________________________________________________________________________________________________________________

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4. Transport Proteins-________________________________________________________________________________________________________________

i. Ex-____________________________________________

ii. Ex-____________________________________________

5. Support Proteins-________________________________________________________

i. Ex-____________________________________________

ii. Ex-____________________________________________

iii. Ex-____________________________________________

6. Motion Proteins-________________________________________________________________________________________________________________

7. Messenger Proteins-________________________________________________________________________________________________________________

i. Ex-___________________________________________ii. Ex-___________________________________________

iii. Ex-____________________________________________

Nucleic Acids ________________________________________________________

________________________________________________________ ________________________________________________________ ________________________________________________________

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Nucleotides are made up of_______________________________________________________________________________________________________________

Two types= ____________________________ ONE FUNCTION !!!!!->

________________________________________________________________________________________________________________________________________________________________________

DNA is the basis of genes and heredity.

Chemical Reactions ________________________________________________________

________________________________________________________________________________________________________________

Write the equation for cellular respiration and label the reactants and products.

What causes bonds in oxygen and glucose molecules to break?

What causes bonds in oxygen and glucose molecules to break?_______________________________________________________________________________________________________________________________________________________________________________________

What happens when new bonds form in carbon dioxide and water? When new bonds form, energy is released and this energy that is

released is equal to the amount of energy that breaks the same bond.

Sometimes bonds can form a chemical equilibrium, meaning they are reversible and the same on both sides of the equation.

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Ex- Blood cells and plasma transport materials throughout the body. Carbonic acid dissolves in the blood so that carbon dioxide can be transported to the lungs.

Chemical reactions release or absorb energy

1.____________________________________________________________2.____________________________________________________________3.____________________________________________________________

Activation Energy ________________________________________________________

________________________________________________________ ________________________________________________________

________________________________________________________

Exothermic ________________________________________________________ ________________________________________________________

________________________________________________________ ________________________________________________________ Ex- firefly squid, fireflies, cellular respiration (releases usable energy

as well as keep your body warm). Endothermic

________________________________________________________ ________________________________________________________ Example- photosynthesis-> plants absorb energy from the sun and

use that energy to make simple and complex carbohydrates.

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Enzymes!!!!!How did the Venus flytrap digest the frog? _______________________________________________________________________________________________________________________________________________________________________________________

Break down food into smaller molecules that the body can use.

What is activation energy? _____________________________________________________________

Most of the time the activation energy for a chemical reaction comes from a _________________________________ sometimes the process is very slow.

In order to speed the process up substances called _______________________________________________________________________________________________________________

When a catalyst (ex- enzymes) is present less energy is needed and products form a lot __________________.

What are two functions of catalysts in chemical reactions?1.2.

Enzymes:

Definition= ________________________________________________________________________________________________________________

Reactants are usually found at very low concentrations in the body, but really need to occur quickly.

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________________________________________________________________________________________________________________

_______________________________________________________ Temperature, concentration, and ph can affect the shape, function,

rate, and activity of the enzyme. ________________________________________________________ If temperature is a little elevated then the hydrogen bonds will fall

apart, the enzyme structure will change, and its ability to function will be lost.

This is the reason why a high temperature / fever is very dangerous to a person.

Examples: 1._______________________________________________________

________________________________________________________ 2._______________________________________________________

________________________________________________________

The structure is so important because ________________________________________________________________________________________________________________________________________________________________________

Specific reactant an enzyme acts on are called ________________________

The sites where substrates bind to enzymes are called ________________________.

Enzymes bring substrate molecules close together, then they decrease activation energy, substrates attach together and their bonds are weakened, and then the catalyzed reaction forms a product that is released from the enzyme.

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Reflection

On a sheet of paper, review the three parts of the lock and key model and write a paragraph (3-5 sentences) describing the analogy. Consider why the model is described as a lock and key. Also identify the different parts and what happens to each part after the reaction is complete. You may use your notes only as a guide.

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