Classes Of Enzymes

Question 1

Oxidoreductase

Answer 1

(Transfer of electrons)
Look for cellular reductants
NAD+/NADH
NADP+/NADPH
FAD/FADH2
Q/QH2

Question 2

Transferase

Answer 2

(Transfer of functional groups)
Same number of products and substrates
A bit of one substrate ends up on the other

Question 3

Hydrolase

Answer 3

(Single bond cleavage by water)
Water + substate = two products

Question 4

Lyase

Answer 4

(Bond cleavage by elimination)
No water
One substrate = two products

Question 5

Isomerase

Answer 5

(Intramolecular rearrangement)
Equal number of substrates and products
Usually one
Substrate and product have same molecular formula

Question 6

Ligase

Answer 6

(NTP-dependent bond formation)
NTP is used
Not incorporated into products
Portion or all of one substrate added to the other
NTP = GTP, CTP, UPT, TTP, ATP