Biochem High Yield (Fa) - Part 2

Front 1

irreversible enzymes in glycolysis (3)

function

Back 1

hexokinase/glucokinase (glucose --> glucose-6-phosphate)

phosphofructokinase-1 [PFK-1] (fructose-6-phosphate -->
fructose 1,6-bisphosphate)*

pyruvate kinase (phosphoenolpyruvate [PEP] --> pyruvate)


* rate-limiting step in glycolysis

Front 2

glucokinase is located in (2)

Back 2

hepatocytes
β-islet cells

(gLucokinase)

Front 3

glucokinase is induced by

Back 3

insulin

Front 4

glucokinase:

Km
capacity

Back 4

high Km (low affinity)
high capacity

Front 5

hexokinase is inhibited by

Back 5

glucose-6-phosphate

Front 6

hexokinase:

Km
capacity

Back 6

low Km (high affinity)
low capacity

Front 7

rate-limiting enzyme of glycolysis

Back 7

PFK-1

Front 8

PFK-1 is directly inhibited by (2)

Back 8

ATP
citrate

Front 9

PFK-1 is directly activated by

Back 9

AMP

Front 10

PFK-1 is indirectly stimulated by

Back 10

insulin
(stimulation of PFK-2 results in fructose 2,6-bisphosphate synthesis)

*fructose 2,6-bisphosphate is the most potent activator of PFK-1*
(overrides inhibition of PFK-1 by ATP and citrate)

Front 11

PFK-1 is indirectly inhibited by

Back 11

glucagon
(inhibition of PFK-2 results in inhibition of fructose 2,6-bisphosphate synthesis)

Front 12

2,3 BPG is synthesized during

Back 12

glycolysis (from 1,3 BPG via mutase)

Front 13

pyruvate kinase:

activated by

inhibited by (2)

Back 13

fructose 1,6-bisphosphate

ATP
alanine

Front 14

function of lactate dehydrogenase (LDH)

Back 14

reduces pyruvate to lactate (NAD+ is regenerated)

Front 15

consequence of reduction of pyruvate to lactate by LDH

Back 15

oxidation of NADH to NAD+

(NAD+ is used in glycolysis by G3P dehydrogenase)

Front 16

DHAP from glycolysis is used to synthesize

Back 16

TG's

Front 17

high-energy intermediates in glycolysis that are used to generate ATP (2)

Back 17

1,3 BPG
PEP

Front 18

pyruvate dehydrogenase is inhibited (3)

Back 18

NADH
ATP
acetyl-CoA

Front 19

glycolytic enzyme deficiencies result in (2)

Back 19

hemolytic anemia (without heinz bodies; e.g., pyruvate kinase deficiency)

increased 2,3 BPG (O2 unloaded from Hb more readily)

Front 20

most common glycolytic enzyme deficiency

Back 20

pyruvate kinase

Front 21

galactokinase deficiency results in

consequence

Back 21

mild galactosemia

galactose is converted to galactitol by aldose reductase in the lens

Front 22

trapping of galactitol in the lens causes (2)

Back 22

swelling of lens

cataracts

Front 23

enzyme deficiency:

catracts early in life
vomiting and diarrhea following lactose ingestion
lethargy
liver damage --> hyperbilirubinemia
mental retardation

Back 23

galactose 1-P uridyltransferase deficiency

("severe galactosemia")

Front 24

fructokinase deficiency results in

Back 24

essential fructosuria-benign condition

(non-glucose sugar detected by urine dipstick test)

Front 25

enzyme deficiency:

vomiting
lethargy
liver damage --> hyperbilirubinemia
hypoglycemia (↓ P --> ↓ glycogenolysis and ↓ gluconeogenesis)
hyperuricemia
renal proximal tubule defect (Fanconi)

Back 25

aldolase B (fructose 1-P aldolase) deficiency

("fructose intolerance")

Front 26

pyruvate dehydrogenase (PDH) complex cofactors

Back 26

thiamine pyrophosphate (TPP) -thiamine (vit. B1)
FAD - riboflavin (vit. B2)
NAD+ - niacin (vit. B3)
CoA - pantothenate (vit. B5)
lipoic acid

(the first four water-soluble vitamins + lipoic acid)

Front 27

PDH:

function

activated by (3)

inhibited by (3)

Back 27

pyruvate --> acetyl-CoA

↑ NAD+/NADH ratio
ADP
Ca2+

NADH
ATP
acetyl-CoA

Front 28

lipoic acid is inhibited by

Back 28

arsenic

Front 29

signs of arsenic poisoning (3)

Back 29

vomiting
rice water stools
garlic breath

Front 30

PDH deficiency is common in

reason

Back 30

alcoholics

(thiamine deficiency-no TPP)

Front 31

PDH deficiency results in

Back 31

lactic acidosis

(pyruvate builds up and is converted to lactate by lactate dehydrogenase)

Front 32

Tx for PDH deficiency

Back 32

increase intake of ketogenic nutrients

Front 33

ketogenic nutrients (3)

Back 33

fats
lysine (purely ketogenic aa)
leucine (purely ketogenic aa)

Front 34

pyruvate is converted to alanine by

Back 34

ALT

Front 35

anaerobic glycolysis is the major energy-producing pathway in (6)

Back 35

RBC's
leukocytes
kidney medulla (very low O2)
cornea
lens
testes

Front 36

rate-limiting enzyme of the TCA cycle

function

Back 36

isocitrate dehydrogenase (IDH)

isocitrate-->alpha-ketoglutarate

Front 37

isocitrate dehydrogenase:

activated by

inhibited by (2)

Back 37

ADP

NADH
ATP

Front 38

α-ketoglutarate dehydrogenase complex cofactors

Back 38

thiaminepyrophosphate (TPP) - thiamine (vit. B1)
FAD - riboflavin (vit. B2)
NAD+ - niacin (vit. B3)
CoA - pantothenate (vit. B5)
lipoic acid

(the first four water-soluble vitamins + lipoic acid)

Front 39

α-ketoglutarate dehydrogenase is inhibited by (3)

Back 39

succinyl-CoA
NADH
ATP

Front 40

only enzyme of the TCA cycle not found in the mitochondrial matrix

location

Back 40

succinate dehydrogenase

inner mitochondrial membrane (complex II)

Front 41

NADH dehydrogenase complex I blocked by (2)

Back 41

barbiturates
rotenone

Front 42

coenzyme Q (ubiquinone) blocked by

Back 42

doxorubicin

Front 43

cytochrome b/c1 (complex III) blocked by

Back 43

antimycin A

Front 44

cytochrome a/a3 (Cu2+), complex IV, and cytochrome oxidase blocked by (3)

Back 44

cyanide
CO
azide

Front 45

ATP synthase blocked by

Back 45

oligomycin

Front 46

uncoupling agents (4)

result in (3)

Back 46

uncoupling protein (UCP)
thermogenin (brown adipose tissue)
2,4-DNP
aspirin

↓ ATP production
↑ O2 consumption
↑ oxidation of NADH