ANS 330 Protein Catabolism

When is protein used for energy?

only in very prolonged exercise, very intense exercise, and malnutrition

Where do amino acids go when they are released from muscle or other tissue?

amino acids are released from muscle or other tissue and are transported to the liver and converted to glucose

What happens after glucose is released into circulation?

it is delivered to working muscles

What happens to some amino acids?

some AAs are converted into various intermediates of oxidative metabolism, pyruvate, acetyl-CoA

Why is the energy yield difficult to determine?

protein contains nitrogen, there are varying amounts of ATP spent in conversion of N into urea, energy yield also varies for different amino acids that can enter the CAC at different points

Muscle fiber capacity to oxidize fat and CHO

difficult to determine

What is the relationship of muscle activity and aerobic activity?

there is a close relationship between muscles ability to perform prolonged aerobic activity and activity of oxidative enzymes

What enzymes are most frequently measured?

succinate dehydrogenase, citrate synthase (both from krebs cycle), 3-hydroxyacyl dehydrogenase (from beta-oxidation)