Chapter 7- Amino Acids (Oct 22)

Question 1

ammonia overflow=

Answer 1

point of max microbial amino acid synthesis from ammonia

Question 2

before ammonia overflow, each increment in dietary crude protein results in

Answer 2

an equal increment in metabolizable crude protein

dietary CP= metabolizable CP

Question 3

What happens to NPN before ammonia overflow?

Answer 3

microbes are still able to make more amino acids using NPN

Question 4

What happens to true protein before ammonia overflow?

Answer 4

• it can be broken down by microbes and used to synthesise microbial AA
  OR
• can bypass breakdown in the rumen and be digested like it would be in a monogastric

Question 5

After point of ammonia overflow, each increment in dietary crude protein results in

Answer 5

NO increment in metabolizable CP

crude protein is still going in, but it can’t be metabolized

Question 6

Summarize what happens before the point of ammonia overflow

Answer 6

rumen microbes are capable of converting a high proportion of NH3 to microbial protein

Question 7

summarize what happens after the point of ammonia overflow

Answer 7

rumen microbes can’t make more microbial protein- ammonia is “wasted”

• microbes still break down true protein
• any increase in metabolizable protein must come directly from dietary true protein

Question 8

In feeds, why is NPN used as a source of ammonia for rumen microbes?

Answer 8

To save money!

• minimize the breakdown of expensive dietary true protein
• maximize the bypass protein
• make some protein unavailable to rumen microbes

Question 9

What are some methods used to maximize bypass protein?

Answer 9

• heat during normal processing
• heat and pressure treatment
• ionophores- drugs that interfere w/ digestion of certain microbes in rumen
• lipid treatment- bacteria/ microbes don’t like fats and oils

Question 10

Catabolism=

Answer 10

degradation (in the body) NOT digestion (which occurs in the lumen of the digestive tract).
- breakdown of larger molecules

Question 11

anabolism=

Answer 11

synthesis of larger molecules

Question 12

anabolism and catabolism occur _____

Answer 12

simultaneously

“turnover”

Question 13

protein metabolism=

Answer 13

synthesis/ degradation of proteins

Question 14

amino acid metabolism =

Answer 14

synthesis/ degradation of amino acids

Question 15

the ___ is the first site of amino acid metabolism

Answer 15

intestine

Question 16

the intestine uses almost 100% of the following amino acids (3) as ____:
(they don’t make it into circulation)

Answer 16

fuel

Glutamine, glutamate, aspartate

Question 17

Other amino acids like threonine, phenylalanine, lysine, and leucine are ~__-__% catabolized by the gut

Answer 17

30-50%