Coordination of Metabolism

Question 1

Intracellular metabolism can be controlled by what?

Answer 1

horomes (glucagon, insulin etc)

Question 2

What are the major branch points in all of metabolism?

Answer 2

glucose-6-phosphate, pyruvate, oxaloacetate, acetyl CoA (can go in different directions)

Question 3

What is the main difference between neuronal and hormonal signalling?

Answer 3

neuronal occurs over a few mm, hormonal can occur across the entire organism

Question 4

What are some examples of cell-surface hormones? How do they work?

Answer 4

insulin, glucagon

bind to receptor on surface and cause a signalling cascade

Question 5

What are some examples of nuclear hormones? How do they work?

Answer 5

steroid hormones

they enter the cell and act in the nucleus directly

Question 6

Which type of hormone acts faster?

Answer 6

cell surface because they alter the activity of existing enzymes instead of altering gene expression like nuclear ones

Question 7

What does insulin do?

Answer 7

increases entry of glucose into muscle and adipose tissue, stimulates glycogen synthesis and glycolysis in liver, more fatty acid syntehsis

Question 8

What is glucagon for?

Answer 8

signal for starved state, increases blood glucose levels, enhances glycogen breakdown

Question 9

What does epinephrine do?

Answer 9

fight or flight hromones, increase cAMP in muscles

Question 10

What posttransaltion modification does insulin undergo?

Answer 10

proteolytic cleavage (goes from preproinsulin to proinsulin) then C-peptide is removed to make insulin

Question 11

What does the pancreas do?

Answer 11

secretes insulin and glucagon in response to cahnges in blood sugar levels

Question 12

What does the liver do?

Answer 12

processes fats, carbs, and proteins, amkes and distributes lipids and ketone bodies and glucose for other tissues, makes urea from nitrogen

Question 13

What can glucose-6-phospahte do?

Answer 13

replenish blood glucose, store glucose as glycogen, make energy through citric acid cycle, make fatty acids via acetyl coa, make nucleotides

Question 14

Amino acids in the liver can be used for what?

Answer 14

making proteins, sent to tissues, make metabolites, broken down to urea, also the carbon skeletons of amino acids can be used for citric, glyconeogenesis, fatty acid synt

Question 15

What is the purpose of the cori cycle?

Answer 15

lactate is made by the muscles and is carreid to liver to make glucose, sent back to be stored as glycogen

Question 16

What does a well fed liver do?

Answer 16

has high insulin, glucose feeds brain is stroed as glycogen and converted to triacylglycerols, transported in VLDL to adipose tissue and muslce,

Question 17

What does a starved liver do?

Answer 17

high glucagon, pyruvate turned to oxaloacetate then glucose, fatty acids are broken down, acetly coa doesn’t do citric instead makes ketone bodies

Question 18

What are the ketone bodies? Which can be metabolized?

Answer 18

acetone, acetoacetate, D-Beta-hydroxybutyrate (not acetone, the other two) acetone is exhaled

Question 19

How many acetyl CoA do you need to make a ketone body?

Answer 19

3, but you get 1 back, net 2`

Question 20

How does acetoacetate differ from the other two ketone bodies?

Answer 20

acetone is decarboxylated version, beta-hydroxybutyrate is reduced

Question 21

How is beta-hydroxybutyraet catabolized?

Answer 21

oxidized then uses a succinyl coa, then a free coa, makes 2 acetyl coa

Question 22

What is the biggest difference in the type of fuel storage between a normal weight vs obese?

Answer 22

triacylglycerols (3 months vs 14 month survival)