exam 2: insulin

Question 1

fendocrine pancreas. is 1%

islet of Langerhan cells:
A cells secrete=
B cells secrete=

D cells= (inhibitor)
F cells=

Answer 1

A cells secrete= glucagon
B cells secrete=insulin

D cells secrete= somatostatin (inhibits A and B cells)

Question 2

majority of the islets of langerhan cells:

Answer 2

a and B cells

Question 3

exocrine portion of pancreas is what releases _____ enzymes into the lumen of the small intestine

Answer 3

digestive

Question 4

a and b cells go into_____ (why called endocrine)

Answer 4

into blood

Question 5

majority of the pancreas is ____ cells that are moved into duadumen for digestion

Answer 5

acinar cells

Question 6

insulin secretion is associated with

Answer 6

energy abundance

Question 7

insulin is composed of two amino acid chains, connected by:

Answer 7

disulfide linkages

and a and b chains

Question 8

when a and b chains are split in insulin, functional activity of insulin molecule is

Answer 8

lost

Question 9

what have virtually no insulin activity

Answer 9

proinsulin and C peptide

Question 10

formation of insulin occurs in ___ cells. it is first made as:

Answer 10

Beta cells

first made as proinsulin

Question 11

in the golgi, proinsulin is cleaved to form

Answer 11

c peptide and insulin

Question 12

insulin circulates entirely in

Answer 12

unbounded form

Question 13

what is the key regulator of insulin secretion

Answer 13

glucose

Question 14

when glucose levels ____, this stimulates insulin synthesis

Answer 14

increase (>3.9 mmol/L)

Question 15

mechanism of insulin secretion.

1. glucose enters cell _____ concentration gradient
2. glucose is metabolized until it produces:
3. when ATP ______, this _____ the SUR channel (sulfonylurea receptor channel)
4. this causes depolarization of:
   moving it:
5. causes Ca2+ channel to:
   exocytosis
6. this kinda pushes the reaction onward and increases levels of cAMP
7. exocytosis of

Answer 15

1. down (high to low)
2. ATP
3. closes channels (it is a K+ gated channel gated by the presence of ATP) aka high atp=closed channel
4. depolarization of K+ moving it away from its equlibrium
5. Ca2+ channel opens (exocytosis)
6. incretins
7. exocytosis of insulin!

Question 16

for treatment for _______, some medications close the SUR channel

Answer 16

type 2 diabetes mellitus

Question 17

hormones produced by the digestive system that work to stimulate insulin secretion BEFORE plasma glucose is elevated.

GLP-1 and GIP

Answer 17

incretins

ozempic!!

Question 18

normal fasting blood glucose is _______mg/100ml

Answer 18

80-90mg/100 ml

Question 19

insulin secretion rises when blood glucose rises above

Answer 19

100 mg/100ml

Question 20

peak insulin secretion occurs when blood glucose reaches

Answer 20

400-600 mg/100 ml

Question 21

what is an antigonist of insulin

Answer 21

glucagon

Question 22

glucagon levels decrease as ____ levels increase

Answer 22

insulin

Question 23

as insulin secretion levels increase, glucose levels

until glucose levels get to

Answer 23

increase

get to 400-600

Question 24

insulin is a ________ receptor

Answer 24

tyrosine kinase-linked receptor

Question 25

the target cells responses: ______= increased glucose uptake especially by muscle cells and adipocytes due to translocation of vesicles containing GLUT-4 to the membrane

Answer 25

FAST in seconds. glucose transport

Question 26

the target cells responses: the membrane becomes more permeable to many amino acids along with potassium and phosphate ions. _______= change in enzyme activity leading to changes in metabolism

Answer 26

slower (10-15 minutes) -fat synthesis -protein synthesis -glycogen synthesis

Question 27

amino acids, ketones, various nutrients, gastrointestinal peptides (GLP-1), and neurotransmitters also influence ____ secretion

Answer 27

insulin

Question 28

the target cells responses: the membrane becomes more permeable to many amino acids along with potassium and phosphate ions. ____= changes in gene expression and growth

Answer 28

slowest (hours to days)

Question 29

insulin promotes muscle glucose uptake and metabolism-anabolic effect via

Answer 29

via GLUT-4: (effects of insulin on muscle)

Question 30

resting muscle membrane is

Answer 30

only slightly permeable to glucose

Question 31

what stimulates increases of glucose transport and how?

Answer 31

insulin via increase in GLUT-4 in the membrane

Question 32

when the glucose comes in, there is going to be conversion of it into glycogen (anabolic effect) which increases:

Answer 32

increases glycogen storage in skeletal muscle and increases protein synthesis and inhibits protein degradation (anabolic effects)

Question 33

effect of insulin on protein metabolism and growth. promotes ________ synthesis and ______. Inhibits:

Answer 33

-promotes protein synthesis and storage -inhibits protein degradation

Question 34

insulin and growth hormone interact SYNERGISTICALLY to promote

Answer 34

growth

Question 35

lack of insulin causes: 1 2

Answer 35

protein depletion and increased plasma amino acids

Question 36

effects of insulin on liver.insulin promotes the ____ and ___ of glucose as glycogen by the liver

Answer 36

insulin promotes the uptake and storage of glucose (as glycogen) by the liver

Question 37

insulin promotes conversion of excess glucose into: and inhibits:

Answer 37

fatty acids inhibits production of new glucose aka gluconeogenesis

Question 38

effect on insulin on fat metabolism. insulin promotes: 1 2

Answer 38

insulin promotes fat synthesis and storage

Question 39

storage form of fatty acids are

Answer 39

triglycerides

Question 40

increase glucose transport into adopocyte, increases number of TG-rich lipoproteins that enter the adipocyte (adipose tissues) which activates _______ in the capillary walls of adipose tissues leads to splitting ______ into fatty acids and absorption into adipocytes

Answer 40

lipoprotein lipase LPL splitting TG (triglycerides) into FA

Question 41

how you break down triglycerides to put FA into blood: we want to block this pathway because we need to store things

Answer 41

hormone-sensitive lipase

Question 42

essential effects of insulin for fat storage in adipose tissue:

Answer 42

-inhibits action of HSL -enhances glucose transport into adipocytes (to store)

Question 43

(effects of insulin on Fat Metabolism) lack of insulin causes _____ and release of _____ into the blood and increases plasma cholesterol and phosphlipids

Answer 43

lipolysis and release of FFA

Question 44

net effects of plasma for major target tissues of insulin:

Answer 44

decrease in all 1. glucose 2. FFA 3. ketoacids 4. amino acids

Question 45

increase insulin secretion when what 3 things are increased: insulin will then let these go back down to normal levels

Answer 45

-blood glucose -blood FFA -blood amino acids

Question 46

what happens for insulin secretion to be decreased

Answer 46

-decreased blood glucose -fasting somatostatin (inhibits insulin and glucagon)

Question 47

other things that increase insulin secretion:

Answer 47

-SUR drugs (close K channel and cause depolarization -GLP-1 -GIP -PNS -insulin resistant; obesity these increase blood glucose and eventually cause insulin to decrease blood glucose levels to keep in window: -glucagon -GH -cortisol