Proteins and Enzymes

List and describe the four levels of protein structure.

1. Primary - The order of amino acids 2. Secondary - The regular pattern of coils or folds of the polypeptide chain 3. Tertiary - The overall three dimensional shape of polypeptide chain 4. Quaternary - The association of two or more polypeptide subunits

Define Catalyst

A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.

What is a disulfide bridge?

A disulfide bridge is a covalent bond derived from two thiol groups.

Define Induced Fit.

A proposed mechanism of interaction between an enzyme and a substrate.

Why is a proteins shape so important?

A proteins shape determines its function.

What is a specific reactant acted upon by an enzyme called?

A substrate is the specific reactant acted upon by an enzyme.

What happens to an enzyme that has broken up a protein?

After an enzyme has broken up a protein it returns to its original shape and will work on another molecule or substrate.

Which monomer is linked together to form proteins?

Amino Acids are protein's monomers.

What is an enzyme inhibitor?

An enzyme inhibitor is a molecule that binds to an enzyme and decreases its activity.

What is the difference between competitive and non-competitive inhibitors?

Competitive inhibitors bind to the enzyme at the active site, preventing substrates from bonding. Non-competitive inhibitors bind to the enzyme not at the active site, therefore not preventing substrates from bonding.

Define Denature

Denature is when an enzyme stops functioning due to high heat.

How do enzymes affect the reactions in living cells?

Enzymes affect the reactions in living cells by lowering the activation energy of the reaction.

Why does each enzyme complete only one job?

Enzymes are highly specific catalysts. An enzyme and its substrate both have very specific shapes designed to fit together.

Define Enzyme

Enzymes are macromolecular biological catalysts. Enzymes accelerate chemical reactions.

True or False: Enzymes are not affected by temperature changes.

False.

Which enzyme would be most active in the stomach?

Pepsin in an enzyme active in the stomach.

Why is primary structure important?

Primary structure is important because the order of amino acids determine where the polypeptide chain will fold based on each acids characteristics, which affects all other levels.

What are the main functions of proteins found in organisms?

Protein is a major source of energy and are involved in the creation of some hormones. They transport and store molecules.

What elements are found in proteins?

Proteins are composed of hydrogen, oxygen, nitrogen, and carbon. Some proteins also contain sulfur.

How does the name of an enzyme typically end?

The name of an enzyme typically ends with "ase".

How many different types of amino acids are there?

There are 20 types of amino acids.

True or False: Enzymes are organic catalysts.

True.

True or False: Enzymes are proteins.

True.

True or False: Enzymes work best a specific pH.

True.