P1: INTRODUCTION TO ENZYMOLOGY

Question 1

It is the study of enzymes that deals with the:
a. Activity of enzymes
b. Chemical reactions it catalyzes
c. Clinical use

Answer 1

Enzymology

Question 2

Enzymes are ______ that increases the speed of reaction.

Answer 2

Protein catalysts

Question 3

Enzymes are biologic proteins that catalyzes biochemical reactions WITHOUT, give the 3 reasons.

Answer 3

1. Without altering the equilibrium
2. Without being consumed
3. Without changed in composition

Question 4

The molecule upon which an enzyme acts.

Answer 4

Substrate

Question 5

Also known as, “Excess energy”, where its minimum energy required to:

1. Start a chemical reaction
2. Raise all molecules in 1 mol of a compound at a certain temperature to the transition state at the peak of the energy barrier

Answer 5

Activation Energy

Question 6

This is the region of the enzyme where substrate molecules BIND and undergo chemical reaction and produces an enzyme-substrate complex.

Answer 6

Active site

Question 7

Active site are often _____?

Answer 7

water-free cavity

Question 8

Not a substrate may bind, changing the shape of the enzyme or confirmation, and changing its ability to either become active or inactive

Answer 8

Allosteric site

Question 9

Give 2 kinds of Allosteric Site. and its function.

Answer 9

1. Allosteric inhibitor: IMPAIRS activity of the enzyme
2. Allosteric activator: ENHANCES activity of the enzyme

Question 10

Results when an enzyme is subject to POSTTRANSLATIONAL MODIFICATION

Answer 10

Isoform

Question 11

This are enzymes existing in DIFFERENT FORMS within the same individual but the SAME ACTION, differentiated from each other based on certain physical characteristics such as:
- Electrophoretic mobility
- Solubility
- Resistance to inactivation

Answer 11

Isoenzyme

Question 12

This are NONPROTEIN MOLECULE that may be necessary for enzyme activity.

Answer 12

Cofactor

Question 13

This are INORGANIC COFACTOR that includes Chloride ion and Magnesium ion.

Answer 13

Activator

Question 14

This are ORGANIC COFACTOR such as Nicotinamide adenine dinucleotide (NAD).

Answer 14

Coenzyme

Question 15

A coenzyme that is BOUND TIGHTLY to the enzyme.

Answer 15

Prosthetic group

Question 16

Apoenzyme + Coenzyme = ?

Answer 16

Holoenzyme

Question 17

Also known as, “Zymogen”, which is the INACTIVE FORM OR PRECURSOR OF ENZYME.

[ADD. INFO] It is then converted to active form when it has reached the site of activity (E.g., Trypsinogen –> Trypsin, Chymotrypsinogen –> Chymotrypsin)

Answer 17

Proenzyme

Question 18

Term used to describe the ability of an enzyme to CHOOSE EXACT SUBSTRATE from a group of similar chemical molecules. Also, the capacity of protein catalysts to recognize and BIND ONLY 1 OR FEW MOLECULES.

Answer 18

Enzyme Specificity

Question 19

Enzymes may recognize and catalyze? Name the 3.

Answer 19

1. Single substrate (Absolute)
   Ex. Urease catalyzes hydrolysis of urea
2. Group of similar substrates (Group)
   Ex. Hexokinase adds a phosphate group to hexoses
3. Particular type of bond (Linkage)
   Ex. Chymotrypsin catalyzes the hydrolysis of peptide bonds