Enzymology

Question 1

Proteins produced by living cells that hasten chemical reactions in organic matter.

Answer 1

Enzymes

Question 2

Measured in terms of their activity and not in terms of their absolute value

Answer 2

Enzymes

Question 3

T or F: The higher the enzyme concentration, the faster the reaction.

Answer 3

True (more enzyme is present to bind the substrate)

Question 4

10 Factors affecting enzyme reaction.

Answer 4

1. Enzyme concentration
2. Substrate concentration
3. Cofactors
4. Inhibitors
5. Isoenzymes
6. Temperature
7. Hydrogen ion concentration or pH
8. Storage
9. Hemolysis
10. Lactescense or milky specimen

Question 5

Example of activators. (CCMPZ)

Answer 5

• calcium
• chloride
• magnesium
• potassium
• zinc

Question 6

Examples of metalloenzymes. (CC)

Answer 6

• catalase
• cytochrome oxidase

Question 7

3 types of inhibitor.

Answer 7

• competitive inhibitor
• non-competitive inhibitor
• uncompetitive inhibitor

Question 8

Physically binds to the active site of an enzyme

Answer 8

Competitive inhibitor

Question 9

Does not compete with the substrate but look for areas other than the active site.

Answer 9

Non-competitive inhibitor

Question 10

Binds to the enzyme-substrate complex

Answer 10

Uncompetitive inhibitor

Question 11

Enzymes are active on what temperature?

Answer 11

25C, 30C, 32C

Question 12

Optimum temp. for enzymatic activity

Answer 12

37C

Question 13

Rate of denaturation is usually significant at what temp.?

Answer 13

40 - 50C

Question 14

Temp. that may result in activation of enzymes

Answer 14

60-65C

Question 15

Most physiologic enzyme reaction occur in what pH?

Answer 15

range 7-8 pH

Question 16

Ideal temp. for preservation of enzyme

Answer 16

-20 deg. C

Question 17

Ideal storage temp. for substrate and coenzymes

Answer 17

2 - 8 degree C

Question 18

Ideal temp. storage for LDH (LD4 and LD5)

Answer 18

22Cto room temp.

Question 19

Hemolysis decreases enzyme concentration. Lactescense/milky spx. increases enzyme concentration.

Answer 19

Both statement is false.
Hemolysis - increases
Lactescence - decreases

Question 20

Catalyze the removal or addition of electrons (redox reaction)

Answer 20

Oxidoreductases
- CO, LDH, MDH, ICD, G-6-PD

Question 21

Catalyze the transfer of a chemical group other than hydrogen from one substrate to another.

Answer 21

Transferases
- CK, AST, ALT, OCT

Question 22

Catalyzehydrolysis or splitting of a bond by the addition of water (hydrolytic reactions)

Answer 22

Hydrolases
- Esterases: ACP, ALP, CHS, LPS
- Peptidases: Trypsin, Pepsin, LAP
- Glycosidase: AMS, Galactosidases

Question 23

Catalyze removal of groups from substrates without hydrolysis. The product contains double bonds.

Answer 23

Lyases
- Glutamate decarboxylase, Pyruvate decarboxylase, Tryptophan decarboxylase and Aldolase

Question 24

Catalyze the intramolecular arrangement of the substrate compound

Answer 24

Isomerases
- Glucose phosphate isomerase and Ribose phosphate isomerase

Question 25

Catalyze the joining of two substrate molecules, coupled with breaking of the pyrophosphate bonding ATP or similar compound.

Answer 25

Ligases - Synthase

Question 26

Based on the premise that the shape of the key (substrate) must fit into the lock (enzyme)

Answer 26

Emil Fisher's/Lock and Key theory

Question 27

Based on the substrate binding to the active site of the enzyme

Answer 27

Kochland's/Induced fit theory

Question 28

An enzymes combines with only one substrate and catalyzes only one reaction is known as ________

Answer 28

Absolute specificity

Question 29

Enzymes combined with all the substrates in a chemical group is called _______

Answer 29

Group specificity

Question 30

Enzymes reacting with specific chemical bonds is known as _________

Answer 30

bond specificity

Question 31

1 micromole of substrate/minute

Answer 31

International Unit (IU or U)

Question 32

1 mole of substrate/second

Answer 32

Katal unit (KU)

Question 33

Enzymes are measured in terms of:

Answer 33

1. Change in substrate concentration 2. Change in product concentration 3. Change in coenzyme concentration

Question 34

The reaction rate depends only on enzyme concentration.

Answer 34

Zero-order reaction

Question 35

the reaction rate is directly proportional to substrate concentration

Answer 35

the reaction rate is directly proportional to substrate concentration

Question 36

It is a nonspecific enzyme capable of reacting with many different substrates.

Answer 36

Alkaline phosphate

Question 37

functions to liberate inorganic phosphate from an organic phosphate ester with the concomitant production of an alcohol.

Answer 37

Alkaline phosphate

Question 38

Major tissue sources of Alkaline phosphate (LBPI)

Answer 38

Liver, Bone, Placenta, Intestinal

Question 39

Reference value of Alkaline Phosphate

Answer 39

30-90 U/L