TCA, B-oxidation, oxidative phosphorylation

Question 1

TCA cycle rxn 1 type

Answer 1

C-C bond formation by claisen condensation

Question 2

TCA cycle rxn 1 enzyme

Answer 2

citrate synthase

Question 3

TCA cycle rxn 1

Answer 3

acetyl-coA + oxaloacetate = citrate

Question 4

TCA cycle rxn 2 type

Answer 4

isomerization

Question 5

TCA cycle rxn 2 enzyme

Answer 5

aconitase

Question 6

TCA cycle rxn 2

Answer 6

citrate to isocitrate
(cis-aconitase intermediate)

Question 7

TCA cycle rxn 2 reason

Answer 7

citrate is a poor substrate for oxidation
isocitrate has secondary -OH which can be oxidized

Question 8

citrate chirality

Answer 8

prochiral: aconitase removes pro-R H of pro-R arm

Question 9

TCA cycle rxn 3 type

Answer 9

oxidative decarboxylation

Question 10

TCA cycle rxn 3 enzyme

Answer 10

isocitrate dehydrogenase
- link to e- transport chain

Question 11

TCA cycle rxn 3

Answer 11

isocitrate to a-ketoglutarate

Question 12

TCA cycle rxn 3 intermediate

Answer 12

oxalosuccinate

Question 13

TCA cycle rxn 4 type

Answer 13

oxidative decarboxylation

Question 14

TCA cycle rxn 4 enzyme

Answer 14

a-ketoglutarate dehydrogenase
- complex

Question 15

TCA cycle rxn 4

Answer 15

a-ketoglutarate to succinyl-coA

Question 16

TCA cycle rxn 5 type

Answer 16

substrate-level phosphorylation

Question 17

TCA cycle rxn 5 enzyme

Answer 17

succinyl-coA synthetase

Question 18

TCA cycle rxn 5

Answer 18

succinyl-coA to succinate
- synthesis is driven by hydrolysis of coA ester

Question 19

TCA cycle rxn 5 product type

Answer 19

nucleoside triphosphate

Question 20

TCA cycle rxn 6 type

Answer 20

oxidation involving FAD

Question 21

TCA cycle rxn 6 enzyme

Answer 21

succinate dehydrogenase

Question 22

TCA cycle rxn 6

Answer 22

succinate to fumarate

Question 23

TCA cycle rxn 6 FAD

Answer 23

FAD to FADH2
part of e- transport chain

Question 24

TCA cycle rxn 7 type

Answer 24

hydration across double bond

Question 25

TCA cycle rxn 7 enzyme

Answer 25

fumarase

Question 26

TCA cycle rxn 7

Answer 26

fumarate to L-malate
- carbanion transition state

Question 27

TCA cycle rxn 8 type

Answer 27

carbon oxidation

Question 28

TCA cycle rxn 8 enzyme

Answer 28

malate dehydrogenase

Question 29

TCA cycle rxn 8

Answer 29

L-malate to oxaloacetate

Question 30

TCA cycle rxn 8: NAD+

Answer 30

NAD+ to NADH + H+

Question 31

B-oxidation step 1 type

Answer 31

oxidation of Ca-Cb bond

Question 32

B-oxidation step 1 enzyme

Answer 32

acyl-coA dehydrogenase

Question 33

B-oxidation step 1 hydride removal

Answer 33

by FAD

Question 34

B-oxidation step 1 rxn

Answer 34

Palmitoyl-coA to trans-delta-Enoyl-coA

Question 35

B-oxidation step 2 type

Answer 35

water added across double bond

Question 36

B-oxidation step 2 enzyme

Answer 36

enoyl-coA hydratase

Question 37

B-oxidation step 2 rxn

Answer 37

trans-delta-enoyl-coA to L-B-hydroxyacyl-coA

Question 38

B-oxidation step 3 type

Answer 38

oxidation of B-hydroxyl group

Question 39

B-oxidation step 3 enzyme

Answer 39

hydroxyacyl-coA dehydrogenase

Question 40

B-oxidation step 3 cofactor

Answer 40

NAD+

Question 41

B-oxidation step 3 rxn

Answer 41

L-B-hydroxyacyl-coA to B-ketoacyl-coA

Question 42

B-oxidation step 4 type

Answer 42

thiolase/reverse claisen condensation

Question 43

B-oxidation step 4 enzyme

Answer 43

thiolase

Question 44

B-oxidation step 4 rxn

Answer 44

B-ketoacyl-coA to acyl coA and acetyl-coA

Question 45

hormone regulation: epinephrine

Answer 45

need energy

Question 46

hormone regulation: glucagon

Answer 46

need glucose

Question 47

ketone body formation

Answer 47

lack of oxaloacetate
acetyl-coA converted into ketone bodies