muscle metabolism

Question 1

what is the cori cycle?

Answer 1

liver breaks down fatty acids. the ATP released is used to perform gluconeogenesis. can take lactate from muscle cells and convert it back into glucose. liver sends the glucose to the muscle for energy.

Question 2

purpose of cori cycle:

Answer 2

prevents lactic acidosis in highly active/functioning muscle cells or other tissues

Question 3

what affect does insulin have on glycosis?

Answer 3

promotes it!
in a well fed state –> want to break down glucose for energy (catabolism-produce energy)

Question 4

what affect does glucagon have on glycolysis?

Answer 4

inhibits it
in a low fed state –> low glucose –> want to perform gluconeogensis (anabolism-use energy)

Question 5

why do tumor cells rely on glycolysis for energy?

Answer 5

rapidly dividing tumor cells cause hypoxia as they are rapidly using up oxygen. this inhibits mitochondrial oxidative phosphorylation. consider it an anaerobic state.

Question 6

what are the 2 results of elevated glucose-6-phosphate in the liver?

Answer 6

increased glycogenesis - increased glycogen and hepatomegaly

increased anaerobic respiration - increased lactate (lactic acidosis)

Question 7

how many ATP molecules are produced per each glucose that enters aerobic glycolysis?

Answer 7

~32

Question 8

purpose of a high fat diet for marathon runners?

Answer 8

have high proportion of slow twitch oxidative fibers
rely on aerobic respiration (mitochondria and ETC)
free fatty acids are primarily metabolized by aerobic respiration (FAs converted into acetyl CoA enter TCA cycle directly)

Question 9

effect of phosphate on glycogen metabolism:

Answer 9

promotes glycogenloysis (glucagon), inhibits glycogensynthesis (insulin)

Question 10

what types of receptors does insulin and glucagon bind?

Answer 10

insulin - tyrosine kinase receptor
glucagon - GPCR/adenyl cyclase