AA metabolism occurs in
Muscle
Liver
____ are absorbed faster than smaller AA
BCAA
___ and ___ absorption is more efficient than free AA absorption
Di- and tri-peptide
Once in enterocyte, peptides broken down into
Free AA for the blood
Low energy charge:
AA is….
Oxidized to recreate ATP
Low glucose:
AA is…
Sent to liver to turn into glucose
High energy charge and lots of glucose:
AA is…
Sent to liver and turned into fat
AA may also be used to synthesize
Protein
Alpha AA can be broken down to
Amino group
Carbon skeleton (alpha keto acid)
Ketoacids can be used to make
ATP
CO2
Glucose
Fat
What happens to an alpha ketoacid depends on
Energy charge
Hormones
Glucose concentration
Tissue
Liver can oxidize
Most of the 20 AA
Muscle can only oxidize
LIVGAA
Alanine alpha ketoacid
Pyruvate
Glutamine/glutamate alpha ketoacid
Alpha ketoglutarate
Asparagine/aspartate alpha ketoacid
OAA
2 AA that cannot turn into glucose
Leucine
Lysine
BCAAs
LIV
Exercise creates ___ in muscle
Low energy charge
Exercise uses the ___ cycle to release glucose into the blood
Glucose alanine cycle
Pyruvate —-> alanine catalyzed by
Alanine transaminase (ALT)
Pyruvate cleared in the liver by ___ in GNG
Pyruvate carboxylase
___ maintainers blood glucose during exercise
Glucose alanine cycle
Carbons in alanine came from
Muscle glycogen
Alanine may provide __ energy during exercise
5%
Low intensity exercise:
No change in ___
20% decrease in ___
Skeletal muscle alanine concentration
Skeletal muscle glutamate concentration
Moderate exercise:
40% decreases in ___
Increase in ___
Skeletal muscle glutamate concentration
Alanine concentration
Glutamine glutamate cycle is used to
Export Nitrogen from muscle to the liver, GI, and immune system
___ adds nitrogen to glutamate to create glutamine
Glutamine synthetase
___ hydrolyzes glutamine into glutamate
Glutaminase
Most AA are released in direct proportion to relative occurrence in muscle protein EXCEPT
LIVGAA
Glutamine
Alanine
Alanine and glutamine released ___ than taken in
More
Alanine and glutamine are the most ____ ____ AA
Abundantly released
LIVGAA are released ___ than taken in
Less
Contains 2 Amino groups
Glutamine
Glucogenic and ketogenic
PITT (sometimes threonine)
Primarily exported by muscle
Alanine
Glutamine
During exercise, muscle takes in ___ and releases __
Glutamate
Alanine
Muscle often uses this AA for nitrogen donation
Glutamine