Carbohydrate Digestion

Question 1

lactose intolerance

Answer 1

do not produce lactase to break down lactose for absorption

Question 2

GLUT1

Answer 2

RBCs

Question 3

GLUT2

Answer 3

liver, kidney, gut

Question 4

GLUT3

Answer 4

brain

Question 5

GLUT4

Answer 5

muscle, adipose

Question 6

GLUT2 affinity

Answer 6

high Km for glucose (low affinity) so can only bind at high concentrations

Question 7

GLUT 1, 3, and 5

Answer 7

can take up glucose at both fasting and fed state due to high affinity

Question 8

GLUT2 can only take up glucose in _ state

Answer 8

fed

Question 9

only _ is insulin sensitive

Answer 9

GLUT4

Question 10

GLUT4 when insulin present

Answer 10

fuses with cell membrane for uptake

Question 11

GLUT4 when insulin absent

Answer 11

located in IC membrane

Question 12

hexokinases

Answer 12

phosphorylate glucose, which prevents it from transport out of the cell, allowing retention

Question 13

hexokinase affinity

Answer 13

high affinity so retain glucose even when low concentrations

Question 14

glucokinase

Answer 14

the hexokinase for liver cells

Question 15

glucokinase affinity

Answer 15

low affinity to lower glucose retention at low circulating glucose levels (allows release of glucose when needed)

Question 16

insulin promotes expression of _

Answer 16

glucokinase and hexokinase II (muscles)

Question 17

glycolysis

Answer 17

glucose –> 2 pyruvate + 2 ATP + 2 NADH

Question 18

glycolysis pathway

Answer 18

glucose –> glucose 6-P –> fructose 6-P –> fructose-1,6-bisphosphate –> glyceraldehyde-3-phosphate + dihydroxyacetone phosphate –> (2) 1,3-BPG –> (2) 3-phosphoglycerate –> (2) 2-phosphoglycerate –> (2) PEP –> (2) pyruvate

Question 19

glycolysis step 1 enzyme

Answer 19

hexokinase + ATP–>ADP

Question 20

glycolysis step 2 enzyme

Answer 20

phosphoglucose isomerase

Question 21

glycolysis step 3 enzyme

Answer 21

phosphofructokinase + ATP–>ADP

Question 22

glycolysis step 4 enzyme

Answer 22

aldolase

Question 23

glycolysis step 5 enzyme

Answer 23

triosephosphateisomerase (DHAP to GAP)

Question 24

glycolysis step 6 enzyme

Answer 24

glyceraldehyde-3-phosphate dehydrogenase + NAD+–>NADH

Question 25

glycolysis step 7 enzyme

Answer 25

phosphoglycerokinsae + ADP–>ATP

Question 26

glycolysis step 8 enzyme

Answer 26

phosphoglyceromutase

Question 27

glycolysis step 9 enzyme

Answer 27

enolase

Question 28

glycolysis step 10 enzyme

Answer 28

pyruvate kinase + ADP–ATP

Question 29

rate limiting enzymes

Answer 29

pyruvate kinase, hexokinase, and phosphofructokinase