Lecture 10 Part 1 Flashcards
what are proteins
- large molecules
- diverse structure and function
- organs and soft structures of body
- enzymes
- signals
- hormones
what are proteins made up of
C
H
O
N
S
what form of nitrogen to animals require
amino acids
why do younger animals have higher requirements of proteins and amino acids
based on body weight
- making a lot of new tissues/muscles
what are the basic structural material for body tissues
muscle
skin
vital organs
blood cells
hormones
enzymes
hair
hooves
feathers
horns
wool
bone
what is the protein structure
- amino acids
- polypeptide (sting of amino acids)
what are the main things in amino acid structure
R group (changes)
amino group
carboxyl group
what are the essential AAs
arginine
histidine
isoleucine
leucine
lysine
methionine
phenylalanine
threonine
tryptophan
valine
what is different in the non-essential AAs glycine and proline in poultry
they will become essential
in nonruminants what are the same as essential AAs
dietary essential AAs
why is it hard to define protein/AA digestion in ruminants
because of role the microbes play
undigested proteins
those that escape rumen and are digested similar to non-ruminants
crude protein
tells us about N available
non protein nitrogen (NPN)
peptides, amines, nucleic acids, amino acids, N containing compounds
- more relevant for ruminants
what can happen if you overfeed urea
cause ammonia toxicity
- need to feed adequate CH3O
Sychrony
Sychrony between N and carbs
- not appropriate for young ruminants
total sulfur amino acids
TSAA
- methionine + cystine
- methionine is essential
- body convert Met into Cystine to avoid deficiency in Met
cysteine
not measured because usually binds together
cystine
2 cysteines bound together with disulfide bond
- cysteine content almost always expressed as cystine
what can phenylalanine converted to
tyrosine (non essential AA)
what is phenylalanine considered
essential amino acid
- rarely limiting AA
true protein
composed of AA
- more important for non ruminants
digestible protein
portion of protein digested
- not all absorbed in SI
- breaking bons
availability
AA may be digested. but is it available for synthesis of protein?
- Maillard reaction
what is the Maillard reaction
- when substance heated
- amino acid and carb bond
- autoclave or oven
- original, autoclave 15 min, autoclave 30 min, over dried 30 min
autoclave vs oven
autoclave is wet/moisture heat while over is dry heat
protein quality of nutritive value
refers to quantity and ratio of essential AA in a protein
biological value (BV)
- relates protein retained to protein absorbed
- equal to or greater than 70% considered capable of supporting growth
limiting AA
AA most deficient in protein or diet relative to requirement
what happens if AA is limiting
protein synthesis stops for all proteins requiring that AA
what are the most common limiting AAs
lysine
methionine
tryptophan
what is the complimentary effect
combining various feeds in order to provide a balance of amino acids
what is an example of complimentary effect
corn, low in lysine, and soybeans, high in lysine
