Lecture 10 Part 2

Question 1

what occurs when there is an AA deficiency

Answer 1

• poor growth
• reduced milk and egg production
• anorexia
• infertility

Question 2

absorption of proteins and AAs during 1st 24 hours after birth

Answer 2

• large proteins
• immunoglobins from colostrum
• these large particles wont be able to be digested after first 24 hours

Question 3

absorption after 24 hours

Answer 3

proteins digested and absorbed as AAs and peptides

Question 4

digestion of proteins

Answer 4

• begins in gastric stomach
• small intestine (pancreatic region) that gives products of free AA, dipeptides, and tripeptides

Question 5

pepsinogen + HCL=

Answer 5

pepsin

Question 6

what hydrolyzes peptide bonds between specific AAs

Answer 6

Pro carboxypeptidase–> carboxypeptidase

Question 7

absorption of AAs and peptides

Answer 7

• occurs in small intestine
• free AAs absorbed by active transport systems
• absorption rate vary

Question 8

ruminant absorption of AAs and peptides

Answer 8

may also occur in rumen and omasum

Question 9

where are dipeptides and tripeptides absorbed

Answer 9

• into mucosal cells
• hydrolyzed to FAA before entering circulation

Question 10

what are AAs used for

Answer 10

• tissue protein synthesis
• synthesis of enzymes, hormones, other metabolites
• transamination-AA biosynthesis
• deamination and use of carbon skeleton for energy

Question 11

tissue protein synthesis

Answer 11

• occurs in every cell of body, hormonal control
• takes place at ribosome
• requires tRNA, rRNA, mRNA, DNA

Question 12

tRNA

Answer 12

caries specific AA and base pairs with mRNA

Question 13

rRNA

Answer 13

part of ribosome

Question 14

mRNA

Answer 14

determines AA sequence of a protein
- codons of 3 nucleotides

Question 15

DNA

Answer 15

genetic code

Question 16

tissue protein degradation

Answer 16

• breakdown of proteins
• fate of AAs from protein degradation

Question 17

breakdown of proteins

Answer 17

• requires proteases
• breakdown to AAs
• stimulated by glucocorticoids

Question 18

what are the fate of AAs from protein degradation

Answer 18

• used in synthesis of protein
• broken down to NH2 and carbon skeleton if body needs energy

Question 19

what are the 2 processes in AA breakdown

Answer 19

• deamination
• transamination

Question 20

deamination

Answer 20

• NH2 removed—> ammonia
• ammonia disposed thru urea cycle
• C skeleton–> keto acid, or gluconeogenesis, or ketogenesis

Question 21

transamination

Answer 21

• resynthesis of AA
• transfer NH2 from AA–>keto acid—>NEAA
• C skeleton—>keto acid, or gluconeogenesis, or ketogenesis

Question 22

what are strictly ketogenic

Answer 22

leucine and lysine

Question 23

why do some AAs have different fats

Answer 23

due to structural uniqueness

Question 24

urea cycle

Answer 24

• excretion of excess N
• occurs in kidney and liver
• several complex steps
• energy expending

Question 25

what are the different forms of N for different animals

Answer 25

fish= ammonia
birds, snakes, lizards= uric acid
terrestrial vertebrates and sharks= urea

Question 26

how is urea excreted and recyclized

Answer 26

• excreted in urine
• in ruminants, recycled thru salvia to help fuel microbes

Question 27

LAAs

Answer 27

limiting amino acids

Question 28

what are the pre ruminants similar too when it comes to AA requirements

Answer 28

nonruminants

Question 29

MCP

Answer 29

ruminally synthesized microbial protein

Question 30

what are unprotected AAs

Answer 30

degraded

Question 31

how do proteins vary

Answer 31

in degree of degradation
- RDP or DIP
- RUP or UIP

Question 32

RDP and DIP

Answer 32

ruminally degraded protein
degraded intake protein
- same thing/meaning

Question 33

RUP or UIP

Answer 33

ruminally degraded protein
undegraded intake protein
- same thing/meaning
- bypass protein

Question 34

how does protein degradation and AA and protein synthesis happen

Answer 34

by rumen microbes

Question 35

bacterial proteins

Answer 35

• high quality
• quantity limits