Animal Nutrition Exam 4

metabolism

the sum processes of chemical changes in living cells by which energy and nutrients are provided for vital processes and activities and new materials are assimilated

anabolism

the constructive part of metabolism involving synthesis (creating new compounds)

catabolism

the destructive part of metabolism involving the release of energy and breakdown of complex materials

oxidation

loss of electrons

reduction

gain of electrons

Glycolysis

anaerobic (no O2)
occurs in cytosol

Kreb's Cycle (TCA)

aerobic (needs O2)
occurs in mitochondria

Oxidative phosphorylation

aerobic (needs O2)
occurs in mitochondriaS

Stage 1 of Glycolysis

priming = uses 2 ATP
Hexokinase (takes P from ATP to make Glucose-6-P)
Phosphofructokinase (takes P from ATP to make Fructose 1,6-P)

Stage 2 of Glycolysis

production
4 ATP produced per glucose (total output of 2 ATP)
generates 2 ATP, 2 NADH, and 2 pyruvate
pyruvate kinase

NADH

electron transport yields 3 ATP per NADH

FADH2

electron transport yields 2 ATP per FADH2

Kreb's Cycle

pyruvate converted to acetyl-CoA (takes place for each pyruvate)
produces 3 NADH, 2 FADH2, 1 GTP, 12 ATP for each acetyl-CoA (24 ATP total for 2 acetyl-CoA)

mitochondrion

function in the synthesis of ATP, major source of energy
electron transport chain is on the inner membrane

oxidative phosphorylation

multi-enzyme complexes located in inner membrane
inner membrane is impermeable to NAD, NADH, ATP and ADP
proton-motive force

proton-motive force

build up of protons in the inter membrane space that drives ATP synthesis down a concentration gradient

ATP synthesis

ATP synthase catalyzes formation of ATP from ADP and P
achieved from flow of protons form inter membrane space matrix
NADH moves 10 protons
FADH2 moves 6 protons
10 protons are needed for one full turn and will make 3 ATP

insulin

increases uptake of glucose, increases fat storage
stimulates the formation of glycogen

Glycagon

Decrease uptake of glucose
stimulates conversion of amino acids to glucose

Glucocorticoids

increases blood glucose (stress response)

Epinephrine

increases blood glucose
decreases fat storage

Glycogenesis

process of making glycogen
muscle and liver
happens immediately following a meal
caused by insulin

Glycogenolysis

breaking down glycogen
caused by glucagon (increases glycogenolysis, increases blood glucose)

Gluconeogenesis

making glucose from non-CHO sources (the reverse of glycolysis)
liver and kidney
very important in ruminants (very little glucose is absorbed; propionate converted to glucose)

Simple lipids

makes up the largest % of lipids
fats, oils, waxes

saturated lipids

single bonds only (as many H as possible)

unsaturated lipids

double bonds

gastric lipase

found in stomach; not very active in mature animals, functional in young animals

pancreatic liapse

primary fat digestion enzyme
secreted with pancreatic juice
secreted in an inactive form
activated by Ca in lumen of SI

Bile

produced by liver and stored in gall bladder
secreted in duodenum
emulsification of fat
arrange triglycerides for hydrolysis of lipase

lipase

cleaves fatty acid from glycerol backbone which exposes the hydrophilic heads

Micelle

free fatty acids and bile salt
can interact with brush border and is the form which lipids are absorbed

chylomicron

made up of triglycerides, proteins, phospholipids, and cholesterol

fatty acid metabolism

oxidation to CO2 for ATP
make glycolipids, phospholipids, and cell membranes
lung alveolar integrity
solubilize ADEK
prostaglandin, sex hormones, adrenal hormones
energy

cortisol

decreases fat storage

glucagon

decreases fat storage

growth hormone

decreases fat storage

fatty acid synthesis

produced from acetyl-CoA from CHO, proteins, VFAs, degraded fats
occurs in cytosol
fats are made 2 C at a time; process continues until fatty acid is 16 C long
fatty acid synthase

B-oxidation

stepwise removal of 2C from fatty acids to make acetyl-CoA (2C)
16C = 8 acetyl CoA
occurs in mitochondria

Ketosis

occurs when an animal has high energy demand
increases fat catabolism = increases acetyl CoA which overloads Krebs cycle and it backs up
converts acetyl CoA to acetoacetic acid (toxic), b-hydroxybutyric acid, and acetone
blood pH decreases = metabolic acidosis

essential amino acids

phenylalanine
valine
threonine
tryptophan
isoleucine
methionine
histidine
arginine
leucine
lysine

glucogenic amino acids

glycine, alanine, threonine, cystine, methionine
converted to krebs cycle intermediates and converted to glucose

ketogenic amino acids

lysine, leucine
converted to acetyl CoA and then to ketones

functions of absorbed proteins

nonessential amino acid synthesis
tissue synthesis
synthesis of enzymes and hormones
deamination
transaminiation

Protein synthesis

complex, involves many systems in body
requires 20 ATP per peptide bond
nucleic acids needed

protein turnover/degradation

constant process since there isn't a storage for amino acids
combination of synthesis and degradation

Deamination

excess AA not needed for protein synthesis are catabolized
break off NH3 from carbon skeleton

Urea

made with 2 ammonia (NH3) and carbon skeletonf

feeding experiment

feed feedstuff/nutrient, compare with standard source/control, measure production response
answers: will they consume it and how well do animals perform
questions: nutrient utilization

Digestion experiment

feed feedstuff/nutrient, sample feed and collect feces, analysis of feed and feces, calculate apparent digestibility coefficient (same equation as percent error)
answers: nutrient absorption in GI tractme

metabolism experiment

feed feedstuff/nutrient, sample feed and collect feces, analysis of feed and feces, collect urine and analyze, calculate nutrient balance
((intake-(fecal+urine))/intake) x 100
answers: nutrients retained

How many total ATP are used in glycolysis?

2 ATP

What process breaks down glycogen?

Glycogenolysis

What enzymes control glycolysis?

hexokinase, phosphofructokinase, pyruvate kinase

Which pathway is responsible for the breakdown of glucose?

glycolysis

Urea is considered a non-protein nitrogen source.

true

What is a function of the stomach during fat digestion?

produce small droplets of fat

What is acetate converted to and what can it then be used to make?

acetyl CoA; ketones

What are the 2 products of deamination of amino acids?

NH3 and carbon skeleton

Microbes can use urea by aminiating then using the NH3 and carbon skeleton to make MCO protein.

true

Where does glycolysis occur?

cytosol

where does the kreb's cycle occur?

mitochondria

Goats require fatty acids in their diet

false

What must be continuously regenerated for glycolysis to continue?

NAD

After a carbohydrate heavy meal, what would you expect insulin and glucagon to do?

insulin decreases and glucagon increases

After a carbohydrate heavy meal, what would you expect gluconeogenesis and glycogenolysis to do?

stop

glycogen synthesis/glycogenesis will occur after a carbohydrate heavy meal.

true

What would be a route that nitrogen can be recycled back to the rumen?

saliva and bloodstream

what hormone would you expect to increase fat catabolism?

epinephrine

What do carbohydrate, fat, and protein metabolism have in common?

acetyl-CoA

What enzyme produces ATP from NADH, located on the inner mitochondrial membrane?

ATP synthase

What describes the over process of fat catabolism?

B-oxidation

What is produced by the liver, stored in the gall bladder, and secreted into the duodenum to aid in fat digestion?

Bile

What is a chylomicron composed of?

triglycerides, cholesterol, phospholipids, proteins

How is butyrate produced?

2 pyruvate -> 2 acetyl-CoA -> butyrate