Regulation Of Blood Glucose

Front 1

What are normal glucose levels?

Back 1

1. 60-100 mg/dL

Front 2

What is the key organ responsible for regulating blood glucose concentration?

Back 2

1. Liver

Front 3

Upon what does glucose transport in the liver depend?

Back 3

1. Insulin

Front 4

What allows glucose to enter the blood from the liver?

Back 4

1. G6P-ase

Front 5

What pathways are active in muscle?

Back 5

1. Aerobic/anaerobic glycolysis

2. Pentose phosphate pathway

Front 6

What do active muscles use for energy?

Back 6

1. Glucose

2. FA

3. Ketones

Front 7

What products of glycolysis can be converted to fat?

Back 7

1. Glycerol-3-P--> TAGs

2. Pyruvate--> acetyl-coA

Front 8

What is the use of insulin in glucose transport in the brain?

Back 8

1. Glucose transport is insulin-independent

Front 9

What metabolic pathways are active in the brain?

Back 9

1. Aerobic glycolysis

2. Pentose phosphate pathway

Front 10

What is the major source of fuel for the brain during starvation?

Back 10

1. Ketones

Front 11

What % of glucose utilization at rest is accounted for by the brain?

Back 11

1. 60%

Front 12

On what metabolic pathway to RBCs depend completely for energy?

Back 12

1. Anaerobic glycolysis

Front 13

What is the purpose of the pentose phosphate pathway in RBCs?

Back 13

1. Provide NADPH for glutathione reductase

Front 14

What component of glycolysis in RBCs regulates HbO2 affinity?

Back 14

1. 2,3 BPG

Front 15

What is the effect of glucocorticoids on blood glucose?

Back 15

1. Increase gluconeogenesis

2. Inhibit extrahepatic uptake of glucose

Front 16

What is the effect of GH on blood glucose?

Back 16

1. Stimulated by hypoglycemia

2. Decrease glucose uptake in muscle

Front 17

Where is preproinsulin synthesized?

Back 17

1. RER

Front 18

What do mature insulin secretory granules contain? (2 elements)

Back 18

1. Equal amounts of insulin and C-peptide

Front 19

What components allow pancreatic B-cells to sense increased blood glucose?

Back 19

1. GLUT-2

2. Glucokinase

Front 20

What substances induce insulin secretion?

Back 20

1. AA-- Arg/Lys

2. FA/Ketones

3. Ach

Front 21

What are the functions of the subunits of the insulin receptor?

Back 21

1. a- extracellular

2. B- transmembrane peptides

Front 22

What activity is inherent in the insulin receptor?

Back 22

1. Tyrosine kinase

Front 23

What is 'tyrosine kinase activity'?

Back 23

1. Two tyrosines on each B-chain in tyrosine kinase are autophosphorylated

2. Phosphorylation of serene and threonine decreases activity

Front 24

What transporter is upregulated by insulin stimulation?

Back 24

1. GLUT-4

2. Transports glucose into the cell

Front 25

How does insulin decrease blood glucose?

Back 25

1. Increase glucose transport in muscle and adipose tissue

2. Induce glucokinase in liver

3. Stimulates glycolysis in liver/inhibits gluconeogensis

4. Stimulates glycogenesis in liver and muscle

Front 26

What is the effect of insulin on nucleic acid synthesis?

Back 26

1. Stimulates protein synthesis

2. DNA/RNA synthesis accelerated

3. Cell proliferation, growth, and differentiation are promoted

Front 27

What is the effect of insulin on lipid metabolism?

Back 27

1. Inhibits lipolysis

2. Stimulates lipogenesis

3. Promotes removal of FA from serum lipoproteins

4. Stimulates LPL

Front 28

What determines the net effect of insulin/glucagon?

Back 28

1. Insulin/glucagon ratio

2. Low-- glucagon predominates

3. High-- insulin predominates

Front 29

What is the effect of epi on glucose metabolism/production?

Back 29

1. Stimulates glycogenolysis

2. Inhibits glucose transport into muscle

3. Increases glucose release by liver

Front 30

What is the effect of epi on glucagon and insulin?

Back 30

1. Stimulates secretion of glucagon

2. Inhibits insulin release

Front 31

What will an excess in insulin cause?

Back 31

1. Hypolycemia

Front 32

When does glucosuria occur?

Back 32

1. When renal threshold for glucose is exceeded (>150 mg/100 mL)