Exam 2 Review Flashcards
Process of glucose metabolism in ruminants
feed nutrients are converted into short-chained fatty acids through microbial fermentation, then the SCFA in the rumen are absorbed into blood circulation
Process of glucose metabolism in non-ruminants
feed nutrients are converted into glucose through digestive enzymes; the glucose in the small intestines absorbs into blood circulation
An important buffer
saliva (breaks down food and controls pH)
Why do the microbes in ruminants need an anaerobic environment?
Too much oxygen kills microbes
How is the symbiotic relationship between ruminants and their microbes mutualism?
Ruminants provide housing and feed (cellulose) while the microbes provide SCFA and protein (through being digested)
Major source of metabolizable energy
SCFA
Major source of metabolizable protein
microbes
important SCFA
acetic acid (2C); propionic acid (3C); butyric acid (4C); when H on COOH is gone they become: acetate, propionate and butyrate
When pH is low there is primarily _______ and the absorption rate is much higher.
acetic acid (has OH group)
When pH is high there is primarily _______ and the absorption rate is much lower
acetate (has O-)
Two primary lipogenic fatty acids
acetate and butyrate
What is propionate?
gluconeogenic
Is increased propionate a good thing or a bad thing? why?
Good thing; propionate is a major glucose source
What is the relationship between the amount of grain in a diet and pH?
Increased grain decreases pH due to the increased amount of fermentation (grain contains fermentable starch)
Milk fat and acetyl coA come from
acetate
Propionate goes to
the liver and then converts to glucose
Beta hydroxybutyric acid (BHBA- a ketone body) comes from
butyrate
Why are high starch/high grain diets susceptible to rumen acidosis
rapid fermentation leads to decreased pH in rumen. After a pH of 6 or lower, lactic acid production occurs then leading to disruption in rumen function
Causes most damage economically to the animal industry; pH is about 5.5; decreased intake, gain, and feed efficiency; difficult to observe
Subclinical rumen acidosis
pH is less than 5; increased lactic acid, damage to papillae; microbial death and release of endotoxins; observable
Clinical rumen acidosis
Glycolipids, phospholipids, sphingolipids, and lipoproteins are all
compound lipids
Dietary component with the slowest rate of digestion in the rumen
cellulose
Dietary lipids exist primarily in this form
Triacylglyerides
Triglycerides are made from these two molecules
fatty acids and glycerol
Which of the following lipids were discovered in brain extracts and named after the mythological sphinx:
sphingolipids
Fatty acids are highly reduced, which means they have a high concentration of:
Hydrogens
Make up the largest fraction (98%) of lipids in animal feeds
simple lipids (fats and oils)
esters of glycerol with a CHO; serve as markers for cell recognition and as an energy source
glycolipids
linked with proteins; synthesized in small intestine and liver; HDL (good) and LDL
lipoproteins
Have higher melting points; pack tightly; have no double bonds
saturated fats
Bend and pack in a less ordered way with greater potential for motion; have one or more double bonds
unsaturated fats
2 indispensable essential fatty acids. 18:2 and 18:3
Linoleic (18:2; omega 6) and alpha-Lionolenic(18:3; omega 3)
Name 3 ketone bodies
Acetone
Acetoacetic acid
Beta-hydroxybutyric acid
Ketone bodies can be used as a source of energy during excess beta oxidation of fatty acids T/F
True
Beta-oxidation of fatty acids results in the generation of acetyl CoA. What is the fate of the acetyl CoA molecule?
It can enter the TCA cycle and it can be converted to ketone bodies in the liver
_____ are responsible for delivering cholesterol to the cells whereas _____ carry cholesterol away from cells and return it to the liver
LDL; HDL
These lipids are critical for transporting hydrophobic molecules in the body
Lipoproteins
The process by which chylomicrons are transported into the lymphatic system
Exocytosis
Dietary linoleic acid is converted by rumen microbes into intermediary FA isomers that are collectively called
Conjugated linoleic acid (CLA)
Omega 3 fatty acid
Linolenic
In ruminants, unsaturated fatty acids are predominantly
Biohydrogenated
Protein quality refers to
amino acid composition and digestibility
A common intermediary formed dring the breakdown of protein and is toxic to animals
Ammonia
A good source of dietary non-protein nitrogen is
urea
Arginine and taurine are required by
cats
These lipids are present in high concentrations in forages
Galactolipids and Glycolipids
In aqueous solutions, amino acids exist as dipolar ions also known as
zwitter ions
an essential amino acid that is available in the lowest concentration
in relation to the body’s needs
limiting amino acid
