Topic 4: Enzymes

Question 1

Most enzymes are…

Answer 1

Proteins

Question 2

Proteins are polymers of….

Answer 2

Amino acids

Question 3

How many R groups are attached to a C in an ionized amino acid? Name them

Answer 3

4. Amino group, R group, carboxyl group, and a H+

Question 4

Amino acids are linked together to form…

Answer 4

peptides

Question 5

A peptide is…

Answer 5

a polymer of amino acids

Question 6

A polypeptide is…

Answer 6

a peptide with more than ten amino acids

Question 7

A protein is…

Answer 7

a polypeptide folded into a fuctional 3D shape (conformation)

Question 8

Primary structure of a protein..

Answer 8

Polypeptide: the raw sequence of Amino acids

Question 9

Secondary structure (2)

Answer 9

The folding of polypeptide into helices and sheets

Question 10

Tertiary structure

Answer 10

When the secondary structure is folded into the 3D shape of a protein (lots of interaction between R groups)

Question 11

Quaternary structure (3 points)

Answer 11

1) only some proteins have it
2) Stabilized by H-bonding among…
3) multiple subunits

Question 12

Types of subunits combinations possible (2):

Answer 12

Homo (same) -trimer (three)
Hetero (different) -trimer (three)

Question 13

Examples of proteins with quaternary structures?

Answer 13

Hemoglobin, polypeptide chain, collagen fibre

Question 14

Describe homopentamer (2 points)

Answer 14

Each subunit has the same primary structure
It has quaternary structure

Question 15

What can the addition of an enzyme catalyst change in a reaction? (2)

Answer 15

The rate of reaction & the activation energy of a reaction

Question 16

In an induced fit model, the enzyme…

Answer 16

changes shape when a substrate enter the active site (pinching it)

Question 17

Which four factors might affect the rate of an enzyme catalyzed reaction?

Answer 17

Enzyme concentration, substrate concentration, temperature, and pH

Question 18

If the final product of a biochemical pathway reduces the function of the first enzyme in the pathway, this is an example of…

Answer 18

feedback inhibition

Question 19

Allosteric enzymes have a…

Answer 19

binding site for inhibitor/activator molecules

Question 20

In ______ structure, of a protein, hydrogen bonds between peptide residues on one polypeptide and peptide residues on another polypeptide contribute to the overall function

Answer 20

Quaternary

Question 21

A peptide bond is…

Answer 21

a covalent bond between Amino acids in a polypeptide

Question 22

Why do chemical reactions tend to speed up then the reactants are heated? (2)

Answer 22

The reactants move faster so they collide with enzymes more often & the collisions between reactants and enzymes are more likely to reach the transition state

Question 23

How can temperature negatively impact enzyme activity?

Answer 23

By denaturing the enzyme