Chapter 19 Regulation of Mammalian Fuel Metabolism and signaling

Question 1

Following a meal, the liver takes up _______ and converts it into _______

Answer 1

glucose
glycogen for storage

Question 2

Muscle cells take up glucose when

Answer 2

it is available and store it as glycogen

Question 3

Excess glucose and amino acids are catabolized to

Answer 3

acetyl-CoA

Question 4

Acetyl-CoA is used to synthesize

Answer 4

fatty acids

Question 5

Fatty acids are esterified to ______ and are exported to ______

Answer 5

triacylglycerol
adipose tissue

Question 6

During a fast, the liver

Answer 6

mobilizes glucose from glycogen stores and releases it into the circulation for other tissue to use

Question 7

What organ deals with lactate and alanine produced by muscle activity

Answer 7

liver
converts into glucose and disposes of Amino groups through urea synthesis

Question 8

In a shortage of glycogen, triacylglycerols are broken down into

Answer 8

acetyl-CoA
converted into ketone bodies to power brain and heart

Question 9

The cori cycle involves what two organs

Answer 9

liver and muscle

Question 10

What does the cori cycle do

Answer 10

transfers free energy from the liver to the muscles

Question 11

The glucose-alanine cycle includes what two organs

Answer 11

liver and muscle

Question 12

Role of the glucose-alanine cycle

Answer 12

transport nitrogen from muscles to the liver

Question 13

The human body buffers itself against fluctuations in fuel supply by

Answer 13

storing metabolic fuels, mobilizing as needed and replenishing them after a meal

Question 14

The activities of organs that store and release fuels are coordinated by

Answer 14

hormones

Question 15

The most important hormone involved in fuel metabolism are

Answer 15

insulin
glucagon
catecholamines-epinephrine and norepinephrine

Question 16

Insulin’s role

Answer 16

regulating fuel metabolism by stimulating glucose uptake and inhibiting glycogen breakdown

Question 17

lack of insulin or inability to respond to it results in

Answer 17

diabetes mellitus

Question 18

increase in circulating glucose triggers

Answer 18

insulin release

Question 19

Effect of insulin on muscle and other tissues

Answer 19

promotes glucose transport into the cell

stimulates glycogen synthesis

suppresses glycogen breakdown

Question 20

Effect of insulin on adipose tissue

Answer 20

activates extracellular lipoprotein lipase

increases level of acetyl-CoA carboxylase

stimulates triacylglycerol synthesis

suppresses gluconeogenesis

Question 21

Effect of insulin on the liver

Answer 21

promotes glycogen synthesis

promotes triacylglycerol synthesis

suppresses gluconeogenesis

Question 22

In short insulin signals

Answer 22

uptake of glucose and storage of glucose and fats

Question 23

Insulin is synthesized in the

Answer 23

beta cells of pancreatic islets

Question 24

The rate of glucose transport into cell increases, not because insulin alters the intrinsic catalytic activity of the transporter but because

Answer 24

insulin increases the number of transporters (GLUT4) at the cell surface

Question 25

Kinases transfer a

Answer 25

phosphoryl group from ATP to another molecule

Question 26

How do the two tyrosine kinase domains of insulin receptor tyrosine kinase get phosphorylated

Answer 26

they phosphorylate each other using ATP as the source of phosphoryl groups

Question 27

the insulin signaling pathway alters the activity of glycogen ____ and glycogen _____

Answer 27

synthase phosphorylase

Question 28

synthesis carried out by glycogen synthase UDP-glucose + glycogen (n residues) ->

Answer 28

UDP + glycogen (n+1 residues)

Question 29

glycogen phosphorylase glycogen (n residues) + Pi ->

Answer 29

glycogen (n-1 residues) + glucose-1-phosphate

Question 30

mTOR is activated by

Answer 30

insulin

Question 31

affects of mTOR being activated

Answer 31

ribosome production protein synthesis nucleotide synthesis lipid synthesis glycolysis reduced autophagy reduced proteasome assembly

Question 32

When the liver must mobilize glucose in order to keep blood glucose concentrations constant what hormones govern this

Answer 32

epinephrine and norepinephrine Glucagon

Question 33

G protein coupled receptors bind

Answer 33

guanine nucleotides GTP and GDP

Question 34

Antagonist of adenosine receptor

Answer 34

natural adenosine caffeine also antagonizes

Question 35

What is the second messenger of G protein coupled receptors

Answer 35

cyclic AMP

Question 36

What enzyme is used to turn ATP into cyclic AMP

Answer 36

adenylate cyclase

Question 37

AMP dependent protein kinase (AMPK) is activated by

Answer 37

cAMP

Question 38

AMPK in the hypothalamus does what

Answer 38

increases food intake

Question 39

AMPK in the liver does what

Answer 39

increases glycolysis increases FA oxidation decreases glycogen synthesis decreases gluconeogenesis

Question 40

What turns off cAMP-dependent signaling

Answer 40

phosphodiesterase

Question 41

how does phosphodiesterase turn off cAMP-dependent signaling

Answer 41

hydrolyzing cAMP to AMP

Question 42

Brown adipose is full of

Answer 42

mitochondria for generating heat especially in newborns and hibernating animals

Question 43

The aldose reductase reaction does what

Answer 43

turns glucose into sorbitol

Question 44

During fuel abundance, excess ____ is (are) catabolized to acetyl-CoA, which is used in fatty acid synthesis

Answer 44

glucose and amino acids

Question 45

insulin is released from pancreatic __ cells in response to ____ blood glucose

Answer 45

beta high

Question 46

Which enzyme is the better sensor of glucose concentration

Answer 46

glucokinase

Question 47

The initial effect of insulin binding on muscle cells is the translocation of

Answer 47

GLUT4

Question 48

The reaction of adenylate cyclase produces the molecule

Answer 48

cAMP

Question 49

Which organ has the capacity to generate glucose through gluconeogenesis

Answer 49

liver kidneys

Question 50

The cori cycle functions to synthesize

Answer 50

glucose in the liver to replenish glucoses in the muscle

Question 51

Glycogen phosphorylase is allosterically ____ by ATP

Answer 51

inhibited

Question 52

The hormone _____ stimulates liver to generate glucose by glycogenolysis and gluconeogenesis

Answer 52

glucagon

Question 53

The hormone ___ stimulates lipolysis in adipocytes

Answer 53

glucagon

Question 54

The hormone ____ stimulates muscle to generate glucose by glycogenolysis

Answer 54

epinephrine

Question 55

The G protein that responds to epinephrine binding to the beta 2-adrenergic receptor

Answer 55

mediates the activation of second messenger production

Question 56

Insulin receptor can ______ and is a _____

Answer 56

auto phosphorylate tyrosine kinase