Enzymes

Question 1

Enzymes are

Answer 1

Most are proteins; two RNA enzymes

Question 2

RNA enzymes

Answer 2

Ribozyme

Ribonuclease P

Question 3

Quarternary structure enzymes

Answer 3

DNA Polymerase

Question 4

Simple enzymes

Answer 4

Pepsin, trypsin

Question 5

Holoenzymes:
What?
Types: what are they, examples

Answer 5

Conjugated enzymes (protein - apoenzyme and non proteins- co factor)

Organic:
Co enzymes (low MW, weakly associate with enzyme during course of reaction)
NAD+, FAD, FMN, Co enzyme A
Prosthetic group (high MW, strong association with apoenzyme)
Haem (in catalase and peroxidase)

Inorganic:
Ion activators (firmly associated with apoenzymes)
Zn2+ (carboxy peptidase and carbonic anhydrase)
Cl- (salivary amylase)
Mg2+ (ATPase)

Question 6

Intracellular enzymes

Answer 6

Enzymes of cellular respiration

Question 7

Extracellular enzymes

Answer 7

Digestive enzymes of digestive tract

Question 8

Who proposed Lock and Key Hypothesis of enzymes?

When?

Answer 8

Emil Fischer

1894

Question 9

Who proposed Induced Fit Hypothesis of Enzymes?

When?

Answer 9

Koshland

1960

Question 10

Competitive inhibition

Answer 10

1. Inhibition of alcohol dehydrogenase by ethanol in methanol poisoning
2. Succinic acid —> Fumaric acid

Question 11

Non competitive inhibition

Answer 11

Cyanide inhibits cytochrome oxidase and blocks ATP transmission
Nerve gas/ di isopropyl fluorophosphate inhibits acetylcholine esterase (muscular paralysis)