Maintaining Glucoes- Lecture 9/20/21

Question 1

Adrenergic response

Answer 1

Response to hypoglycemia, minor symptoms including trembling, palpitations, sweating etc

Question 2

Neuroglycopenic response

Answer 2

Severe hypoglycemia (<54 mg/dL), more severe symptoms including confusion weakness drowsiness

Question 3

Glucagon synthesis

Answer 3

In alpha pancreatic cells

Question 4

Glucagon target tissues

Answer 4

Liver and adipose signals

Question 5

Insulin made in

Answer 5

Beta cells of the pancreas

Question 6

Insulin targets

Answer 6

Liver, adipose tissue, skeletal muscle

Question 7

Glycogen

Answer 7

stored poly glucose, sustains blood levels for a few hours after meal

Question 8

Glucose o genesis

Answer 8

De novo glucose synthesis, many days after eating

Question 9

Hours after eating dominant form

Answer 9

Food glucose to about 4 hours, glycogen glucose from 4-16, gluconeogenesis from 16+
(Glycogen runs out after about a day(

Question 10

Glycogen structure

Answer 10

Linked alpha 1-4 with 1-6 branches

Question 11

Phosphoglucomutase

Answer 11

Rearranges glucose-6-phosphate to glucose-1-phosphate

Question 12

Glycogenin

Answer 12

Initiates glycogen synthesis by self-glycosylating

Question 13

Glycogen synthase

Answer 13

Adds single nucleotide glucoses to the growing chain, major regulated enzyme of glycogen synthesis

Question 14

Branching enzyme

Answer 14

Takes 7 glucoses off of the growing chain and transferred to 1-6 linkages

Question 15

Glycogen phosphorylase

Answer 15

Cleaves a glucose of the glycogen during breakdown, product is glucose-1-phosphate, major regulated step, can’t cleave within 3 glucoses of a branch

Question 16

Debranching enzyme

Answer 16

Cleaves three off a branch and puts it on another chain 1-4 linkages, cleaves the last one to free glucose

Question 17

enzyme differences in muscle and liver

Answer 17

Muscle lacks glucose-6-phosphatase, can’t export glucose uses it for itself

Question 18

Insulin effect on glycogen

Answer 18

Stimulates synthesis

Question 19

Glucagon effect on glycogen

Answer 19

Stimulates break down

Question 20

Phosphorylase kinase

Answer 20

Phosphorylates glycogen phosphoryalase, more active when phosphorylated,

Question 21

Phosphorylase kinase regulation

Answer 21

“A”form is more active because it is phosphorylated by phosphorylase kinase, glucagon istimulates and insulin inhibits

Question 22

Phospho-glycogen synthase

Answer 22

Less active, protein kinase stimulated by glucagon

Question 23

Cellular locations of gluconeogenesis

Answer 23

Mitochondria: Pyruvate carboxylase rxm
Cytoplasm: Most rxns
ER: glucose-6- phosphatase rxn

Question 24

Pyruvate carboxylase

Answer 24

Pyruvate to oxaloacetate

Question 25

PEP carboxylase

Answer 25

Oxaloacetate to PEP

Question 26

Biotin

Answer 26

Cofactor for PEP carboxylase,

Question 27

Oxaloacetate shuttle

Answer 27

Turned to malate or aspartate in mitochondrial matrix, shuttled out and regenerated, (making an NADH in the cytoplasm needed for gluconeogenesis)

Question 28

Fructose 1,6 bishosphatase

Answer 28

fructose 1,6 bisphsphate to fructose 6 phosphate, highly regulated, inhibited by fructose 2 6 bisphoshate

Question 29

Regulators for glucose oxidation

Answer 29

Stimulators: Insulin, F2,6 BP, AMP
Inhibitors: AMP

Question 30

Regulators of Glucose synthesis

Answer 30

Stimulants: Glucagon, epinephrine, cortisol, Acetyl-CoA, Citrate
Inhibitors: F 2,6 BP, AMP

Question 31

Regulators of Fructose 1,6 bisphosphatase

Answer 31

Inhibitors: AMP, F2,6, BP
Activators: Citrate

Question 32

Cori cycle

Answer 32

Lactate (and alanine) created in muscle can be transported into the liver and made into glucose (for muscle)

Question 33

Von Gierke disease

Answer 33

Type one GSD, Defect in glucose-6-phosphatase, can’t export glucose

Question 34

Cori’s disease

Answer 34

Debranching enzyme defect, like van gierke but milder

Question 35

McArdle disease

Answer 35

Skeletal muscle glycogen phosphorylase defect, usually seen in adulthood and does not effect liver