UNIT 3: BIOCHEMISTRY/ENZYMES

Miss Sabia 8A

Essential Question

How do organic and inorganic

compounds compare?

First things first…• Element: a pure substance that

consists entirely of one type of atom• Compound: chemical substance

formed by the combination of 2 or more elements in definite proportions

• For example, H2O is made of 2 hydrogen atoms and 1 oxygen atom

First things first• A chemical formula tells us the

type of elements that are in a compound and the ratio in which those atoms combine

• Glucose, C6H12O6

Some quality bonding time…

• Hydrogen Bonds: weak bonds of attraction between the partially charged H atom and another partially charged atom– Between water molecules

Some quality bonding time…

Ionic Bonds• Electron transfer due

to electrical attraction between ions

• Form cations (+) and anions (-)

Covalent Bonds• Electron sharing• Can be polar (unequal

sharing) or nonpolar (equal sharing)

Electronegativity: “greediness” for electrons; attraction of an atom for electrons in a covalent bond

Organic Compounds• CONTAIN CARBON!!• Most also contain hydrogen• Associated with living things

Why is carbon so special?

• Think of carbon as the jack-of-all-trades

• Has potential to form many kinds and combinations of bonds with many different atoms—able to form 4 covalent bonds

Essential Question

What are the four classes of organic

molecules?

The Macromolecules• Carbohydrates• Nucleic Acids• Proteins• Lipids

Carbs

Lipids

Nucleic Acids

Nucleic Acid

Proteins-Amino Acid

Protein

Activity• You will make a placemat about the 4

types of carbon molecules. Include:• 1. a picture of a food that contains each

type of molecule (you may not be able to find one for nucleic acids, which is fine).

• 2. For each molecule, include a description, as well as a drawing of what the actual carbon molecule looks like.

• 3. Your placemats will be laminated and ready for you to use!

Do Now• Name as many functions of a protein

as you can…

Essential Question

•How is a protein’s function determined?

How do we get these macromolecules?

• When we eat, large organic food molecules such as proteins and starches must initially be broken down to enter cells

• Proteins amino acids• Starches simple sugars• These nutrients can now enter the

cell and be used as building blocks of compounds needed for life

Vocabulary• Monomer: single unit• Polymer: many monomers

Reactions• Dehydration synthesis: joining

molecules together, results in loss of water

• Hydrolysis: breakdown of polymers through the addition of water

A closer look at Proteins

• SHAPE DETERMINES FUNCTION!!!!!!• 4 levels of protein structure– 1. primary– 2. secondary– 3. tertiary– 4. quaternary

Primary Structure• Amino acid sequence

Secondary Struture• Coiling or folding of the a.a.

sequence due to hydrogen bonds

Tertiary Structure• Irregular contortions from

interactions between side chains (aka R groups)

• This involves…– Hydrogen bonding– Ionic bonding– Hydrophobic interactions

Tertiary Structure

Quaternary Structure

• Grouping of polypeptide chains

SHAPE DETERMINES FUNCTION

INSULIN

How is the structure determined?

• Structure depends on the environment– pH– Temp– Salt []

Denaturation• A poor environment may result in

denaturation (breaking of a protein)– Cooking an egg– Getting a fever

It all comes down to amino acids

•What do you think happens if you change the sequence of amino acids?

Essential Question•What is the role of enzymes in a chemical reaction?

Essential Question• What factors affect the rate of

enzymatic reactions?