Test 3: lecture 9

Question 1

endocrine function of pancrease

Answer 1

by the islets of langerhans

beta cells produce- insulin and amylin

aplha cells produce glucagon

delta cells produce somatostain

Question 2

beta cells produce-___

alpha cells produce ___

delta cells produce ___

Answer 2

insulin and amylin

glucagon

somatostain

Question 3

delta cells produce ___ which ___

Answer 3

somatostatin

inhibit alpha and beta cells- inhibits insulin and glucagon

Question 4

insulin is made of ___

Answer 4

small peptide hormone

two chains connected by disulfide bond

made by beta cells in the islet of langerhans in the pancreas

made as precursor preproinsulin

Question 5

what is the precursor of insulin

Answer 5

preproinsulin

Question 6

how does preproinsulin become insulin

Answer 6

signal peptide cleaved to form proinsulin

GH → IGF-1 (somatomedin C)

c- protein degradation by insulinase in the liver → insulin

Question 7

C protein of proinsulin is similar to

Answer 7

GH → IGF-1 (somatomedin C)

Question 8

formation of insulin receptor

Answer 8

2 alpha 2 beta subunits

binding of insulin causes Beta subunit to be phosphorylated and becomes a kinase that will phosphorylate other enzymes

Question 9

binding of insulin to insulin receptor causes

Answer 9

glucose transport, protein synthesis, fat synthesis, glucose synthesis, growth and gene expression

Question 10

where are GLUT4

Answer 10

insulin-dependent tissues (muscle and adipose tissues).

Question 11

where kind of GLUT are in insulin independent tissues

Answer 11

GLUT 1,2,3,5

Question 12

what kind of GLUT are Beta cell glucose sensor

Answer 12

GLUT2

Question 13

when insulin bind to the receptor it causes GLUT4

Answer 13

to move from golgi to the plasma membrane

stimulates glucose uptake

Question 14

uptake of monosaccharides

Answer 14

insulin independent

Question 15

metabolic effects of insulin

Answer 15

Profound effects on metabolism of carbohydrate, fat and protein.

Promote storage of glucose as glycogen

Promote protein synthesis and storage

Promote fat synthesis and storage

Insulin is associated with “energy abundance”.

Question 16

___ increases protein and fat synthesis and storage

Answer 16

insulin

Question 17

insulin promotes storage of ___ as ____

Answer 17

glucose

glycogen

Question 18

insulin causes the increased uptake, storage and use of glucose by most tissues:

Answer 18

liver, muscle and adipose tissue

Question 19

Lack of insulin causes ___

Answer 19

hyperglycemia (high blood sugar)

Question 20

what enzymes are stimulated by insulin

Answer 20

glucokinase

glycogen synthase

glycogenesis → formation of glycogen from glucose

Question 21

why cant glucose be stored in the liver

Answer 21

too much osmotic pressure

needs to be stored as glycogen

Question 22

if there is excess glucose where is it stored

Answer 22

first in the liver as glycogen

then in the muscles as glycogen

then converted into fatty acids (triglyceral) and stored in the liver

Question 23

effect of insulin on fat metabolism

Answer 23

promotes fat synthesis and storage

Insulin increases utilization of glucose by most tissues - fat sparer.

Insulin promotes fat synthesis in the liver.

Insulin promotes fat storage in the adipose cells.

Question 24

how to form fat synthesis in the liver

Answer 24

glucose → triglyceride in liver then lipoprotein lipase → fatty acids which can be taken into cells and converted back into triglycerides for storage

Question 25

Insulin activates ___ in the capillary walls of adipose tissue to release fatty acids.

Answer 25

lipoprotein lipase

Question 26

Insulin promotes glucose transport into fat cells –> a-glycerophosphate –> ___ portion of fats.

Answer 26

glycerol

Question 27

insulin ___hormone-sensitive triglyceride lipase in adipose cells.

Answer 27

inhibits

Question 28

insulin deficiency causes

Answer 28

increase hormone-sensitive lipase –> lipolysis of triglycerides and release of free fatty acids.

increase conversion of fatty acids into cholesterol and phospholipids in the liver.

Excessive usage of fat causes ketosis and acidosis. Fatty acids –> acetyl Co-A –> acetoacetic acid –> acetone and b-hydroxybutyric acid.

Question 29

insulin deficiency causes ___ hormone-sensitive lipase –> lipolysis of triglycerides and release of free ___

Answer 29

increase

fatty acids.

Question 30

insulin deficiency causes ___ conversion of fatty acids into cholesterol and phospholipids in the ___.

Answer 30

increased

liver

Question 31

insulin deficiency causes excessive usage of fat causes ___

Answer 31

ketosis and acidosis.

glucose can’t be used so body uses fat for energy

Question 32

insulin deficiency increases the metabolic use of ___

Answer 32

fats

use fats instead of glucose for energy

Question 33

what happens if you remove pancreas

Answer 33

profound effect on fatty acid metabolism

Question 34

how does insulin effect protein metabolism

Answer 34

Insulin promotes protein synthesis and storage

increases transport of amino acids into the cells.

increases transcription and translation.

decreases protein catabolism.

decreases gluconeogenesis in the liver.

Insulin deficiency causes protein depletion and increased plasma amino acids.

Insulin and growth hormone function synergistically to promote growth.

Question 35

insulin will cause the ___ of protein catabolism and gluconeogenesis in the liver.

Answer 35

decrease

Question 36

insulin will cause the ___ transport of amino acids into the cells and the ___ transcription and translation.

Answer 36

increased

increased

Question 37

Insulin ___causes protein depletion and increased plasma amino acids.

Answer 37

deficiency

causes weight loss

Question 38

both ___ and ___ are required for growth

Answer 38

GH and insulin

to allow uptake of all 20 amino acids into the cells

Question 39

what are some stimulators of insulin secretion

Answer 39

Increased blood glucose

Increased blood free fatty acids

Increased blood amino acids

Insulin resistance; obesity

Cortisol

Growth hormone

Question 40

what are some inhibitors of insulin secretion

Answer 40

Decreased blood glucose

Fasting

Somatostatin

Catecholamines

Question 41

catecholamines and somatostatin will cause ___

Answer 41

inhibit of insulin secretion

somatostatin (IGF-1)

Question 42

___ is secreted by alpha cells in the islets of langerhan and stimulate ___ and ___

Answer 42

glucagon

increase breakdown of glycogen in the liver (glycogenolysis)

increase gluconeogenesis in the liver. (making glucose)

Question 43

precursor for glucagon can also turn into ___

Answer 43

preproglucagon

other peptides in the GI

Question 44

stimulators of glucagon secretion

Answer 44

Decreased blood glucose

Increased blood amino acid

Exercise

Question 45

inhibition of glucagon secretion

Answer 45

Increased blood glucose

Somatostatin (Islet delta cells)

Question 46

how is blood glucose regulated

Answer 46

insulin tries to lower BG

glucagon tries to increase BG

Question 47

Severe ___ stimulates sympathetic system to release ___ which causes ___

Answer 47

hypoglycemia

Epinephrine –> release of glucose from the liver

Question 48

Prolonged hypoglycemia leads to release of ___ and cortisol.

Answer 48

GH

Question 49

severe hypoglycemia decrease the rate of glucose utilization by most cells (___ resistance) and cause ___

Answer 49

severe hypo → causes release of GH and cortisol

insulin

stimulate gluconeogenesis by the liver (make glucose in the liver)

Question 50

what three tissues use only glucose for energy

Answer 50

brain

retina

gonads

(insulin has no effect on these tissues)

Question 51

what tissues have no effect by insulin

Answer 51

brain

retina

gonads

Question 52

type 1 DM

Answer 52

insulin-dependent diabetes (IDDM)

not enough insulin made

occurs randomly 10%, usually in younger people

plasma glucose is increased and plasma insulin is low or absent

treatment: give insulin

Question 53

Type II DM

Answer 53

non-insulin-dependent diabetes (NIDDM), insulin resistance.

happens in older obese people (80-90%)

increased plasma glucose and insulin

insulin can’t get into cells= decreased insulin sensitivity

treatment: diet and weight loss and insulin and other drugs

Question 54

what can cause DM

Answer 54

Genetic predisposition

Pancreatic injury: trauma, neoplasia, infection, autoantibodies, inflammation, drugs (Type I)

Hormone-induced b-cell exhaustion: growth hormone (too much GH in gigantism), cortisol (too much cortisol).

Target tissue insensitivity (Type II)

Decreased number of insulin receptors

Defective insulin receptors

Defect in post-receptor signaling