Cellular Respiration Chapter 6.7

Question 1

What happens proteins when they are digested.

Answer 1

They break down for amino acids. The cell does not use most of these amino acids to produce ATP, instead, most are incorporated into proteins.

Question 2

When an organism depletes its immediate carbohydrate supply, cells may use amino acids as an energy source. How is broken down for energy in CR

Answer 2

1. Ammonia is stripped from the amino acid and excreted.
2. The remainder of each molecule enters the energy pathways as pyro ate, CoA, or an intermediate of the Krebs cycle, depending on the amino acid

Question 3

How is fat digested and used for energy

Answer 3

1. Enzymes in the small intestine digest fat molecules from food into glycerol and 3 fatty acids which enter the blood stream then into cells.
2. Glycerol becomes pyruvate by enzymes and proceed through the rest of the pathway as a if it were originally glucose
   3.fatty acids enter the mitochondria
   Where they are cut into many 2 carbon pieces that are released as CoA then continues down the pathway.

Question 4

How does the body store extra calories as fat.

Answer 4

By diverting acetyl CoA away from the Krebs Cycle and use it to build fats

Question 5

How many 2 carbon CoA does fats produce

Answer 5

Approx 30
Each fat molecule has 3 fatty acid
Each fatty acid have about 20 carbon atoms