Principles of Animal Nutrition Midterm, Part 1

triglycerides

are esters of glycerol and FA and make the storage form of fat in body; the position of the FA on the gylcerol can influence the absorption and utilization of...; most abundant fat

TG with saturated FA

contain 10 or more carbons are solid at room temperature; contain fewer than 10 carbons usually are liquid

lecithin

a mixture of fats that are essential to cells in the human body

FA, phosphoric acid, usually a glycerol, and a nitrogenous base

the hydrolysis (the chemical breakdown of a compound due to reaction with water) of phospholipids such as lecithin (a mixture of fats that are essential to cells in the human body) produces:

polar

likes H2O

sphingomyelins

do not contain glycerol, but contain FA, choline, phosphoric acid, nitrogenous base and sphingosine

myelins

counting of nerves

head

polar

tail

non- polar

phospholipids

have higher unsaturated FA than TG in animals; can be in fats and water; these in animals are more widely dispersed in body fluids; the emulsifying properties allow them to function as lipid transporters

cholesterol

most abundant sterol in animal tissue

sterols found in animals

ergosterol, 7-dehydrocholesterol, bile acids, androgens (male sex hormones), and estrogens and progesterones (female sex hormones)

triglycerides hydrolysis

yields glycerol and FA, which are sources of energy

digestibility of fats

can influence their utilizable energy (true ___ > 80%, carbs = 90%); reduced by diseases that cause malabsorption, low content of dietary lipids, high proportion of dietary waxes or sterols

essential fatty acids (EFA)

cannot be made in the body; serve as a solvent in fat-soluble vitamins absorption; linolenic acid (C18:3) (omega-3 and omega-6 fatty acids); maintain normal body functions: (integral part of the structure of cell membranes)

semi-essential fatty acids

linoleum acid (C18:2); arachidonic acid (C20:4) is synthesized from C18:2

skin structure as a deficiency of EFA

causes dermatitis and other abnormalities and scaly skin and necrosis of the tail

EFA deficiency

results in: growth failure, reproductive failure, edema, subcutaneous hemorrhage, and poor feathering in chicks

EFA as a precursor of eicosanoids

lower blood pressure, stem;ate stomach muscle contraction, inhibit norepinephrine (flight or fight)-induced release of FA from adipose tissue, modulate immune function, immunosppressive

prostaglandins

immune repsonse

conjugated linoleic acid (CLA) isomers

fatty acid supplements in dairy and red meat; protective against cancer, diabetes, atherogenesis, and obesity; modulation of immune function and bone growth

biological activity of different isoforms of CLA

cis-9, trans-11 is anticarcinogenic; trans-10, cis-12 inhibits milk fat synthesis in dairy cows and back fat depth in pigs

fat-soluble vitamins (A, D, E, K)

digestion and absorption of fats influence the absorption of what?; dispersed in micelles similar to those formed for the FA

rare

only a little fat is needed for micelle formation, so deficiencies of fat-soluble vitamins are what?

chain length of FA and degree of unsaturation of FA

what factors do influence the physical and chemical properties of TG?

lipid transporters, storage form of fat, and form cellular membrane

what are the functions of phospholipids, TG and sterols in animals body?

energy supply, essential fatty acids, and carrier of the fat-soluble vitamins

what are the key functions of fats (lipids) in animal nutrition?

omega-3 and omega-6 fatty acids; serve as a solvent in fat-soluble vitamins absorption, maintain normal body functions, and are precursors of eicosanoids

what are the essential fatty acids (EFA) and their role in animal nutrition?

fat/lipid droplets

in the stomach, churning and contractions create what?

chyme

contains fat/lipid droplets and is entered into small intestine via pyloric sphincter

dietary lipids

mixed with bile and pancreatic and intestinal secretions in small intestine; makes it more hydrophilic (dissolve by water)

fats

emulsified by bile salts and the mixing action of the intestine; can't travel in the blood because blood is mainly H2O and they can't move, this is why they are covered in proteins

emulsification

increases surface area, which enhances lipase's effectiveness

lipase

enzyme that comes from pancreas and small intestine; enzyme that attacks fat

lipid particle size

reduced to spheres of 500 to 1000 u.m. (micrometers) in diameter

pancreatic and intestinal

lipases that hydrolyze small particles of fats of FA and glycerol; different types of lipases but do same job

monoglycerides and FA

combine with salt-phospholipids-cholesterol micelles to form mixed micelles; product of lipase hydrolyze

passive diffusion

only for small FA

entero

intestine cells

bile acids

cholic, deoxycholic, taurocholic, glycocholic acid; fats and amino acids

digestion and eye problems

what does lack of bile acids cause?

monoacylglycerol (MAG) and free FA (FFA)

absorbed in brush border

95%

what percent of bile salts are reabsorbed from jejunum and ileum recycled into liver?

free FA (FFA) and lysophospholipid

by the action of pancreatic and intestinal lipases, phospholipids are hydrolyzed to:

glycerol and short-chain FA (C2-10)

absorbed by passive transport into the portal system

poorly

except free cholesterol and vitamin D, most other dietary sterols are absorbed how?

free cholesterol

esterified in the mucosal cell before entering the lymph system via lacteals

mucosal cell

long-chain FA are converted to fatty acyl coenzyme A in the presence of ATP; fatty acyl coenzyme A reacts with monoglycerides to form triglycerides

endoplasmic reticulum

makes protein

chylomicron

fats covered with protein

reverse pinocytosis

chylomicrons leave the mucosal cell by ___ ___ and enter the lymphatic system via lacteals

lymphatic system

containing the chylomicrons lead to blood via the thoracic duct; birds and poultry don't have this

bile salts and fats; increases surface area of fat which makes lipase very active

what are the emulsifying agents in the GI tract and how emulsification helps fat digestion?

proximal (upper) jejunum

where is the main site for absorption of lipids?

short chain are absorbed by passive transport into the portal system, long chain are converted to fatty acyl coenzyme A in the presence of ATP

what is the difference between absorption of short chain and long chain FA?

fats covered with proteins in the mucosal cell; leave mucosal cell by reverse pinocytosis and enter the lymphatic system via lacteals; transport dietary fats

what are "chylomicrons"? how are they formed and absorbed? what it their target?

liver

what organ makes the most fat in the body?

lipemia

the large increase in lipids of the blood after absorption of fat is called what?

chylomicrons; they are transported in the form of lipoproteins ranging from very low to high density molecules

what are the sources of lipids in the blood plasma and how are they transported?

lipoproteins

mix of proteins and lipids; transported by a long chain

density

the ___ of lipoproteins increases as the proportion of protein in the complex increases and the lipid decreases

adipose

what tissue has the highest amount of storage of fat?; all body tissues store TG, but ___ (fat depots) are the most notable storage sites

chylomicrons, very low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), high-density lipoproteins (HDL); the higher amount of protein, the higher the density in that molecule

what are the five classes of lipoproteins and how are they compared?

VLDL

if ___ is high, its not good and means you have lots of unhealthy fats

HDL

if ___ is high, its a good type of fat, doesn't have lots of triglyceride; highest amount of protein in lipoproteins

chylomicrons

lowest amount of protein in lipoproteins; one form of lipoproteins circulating in the blood

VLDL, IDL, LDL, and HDL

synthesized in the liver and small intestine

free fatty acids (FFA)

transported in connection with blood albumin

chylomicrons and other lipids

removed immediately from the blood by the liver, fat depots and other tissues

albumin

a carrier of short-chain FA in the blood; egg white is basically this; best type of protein found in nature

insulin

can be good or bad making fat in the body; hormone and protein; not considered a big protein; liver and fat tissue and muscle tissue are effected by this

breaks down fat in the form of triglycerides; insulin

What is lipoprotein lipase? How is it activated?

adipose cells (adipocytes)

fat tissue

LPL

abbreviation for lipoprotein lipase

composition, concentration

___ and ___ of lipids in the blood are determined by: the type and quantity of dietary lipid, the time after a meal, species, age, endocrine status

levels of total cholesterol, LDL, HDL, and VLDL cholesterol

in the blood are influenced by: diet, endogenous synthesis in liver, intestine, and other tissues, and genetic factors: endogenous cholesterol synthesis, catabolism and excretion

free cholesterol, cholesterol, phospholipid

the ratio of ___ ___ to ___ ___ or to ___ is rather constant in healthy animals within species

deposition, mobilization

stored TG are sources of energy, so continuous ___ and ___ occur in adipose tissue.

brown fat

young animals have ___ ___ mainly in their shoulders that helps regulate body temp. by regulating heat; goes away when they get older

net deposition

energy intake in excess of body need results in a ___ ___ of TG (fattening)

net loss

energy intake less than body needs (as in fasting) results in a ___ ___ of TG

depot fat in ruminants is less responsive to dietary FA composition and are also characterized by odd-length and branched-chain FA; FA composition of the depot fats in non ruminants resembles that of the diet

How is the depot fat composition of ruminants and non ruminants influenced by dietary fat composition?

fat tissue

very dynamic; ex. difference between ruminants and non ruminants

protein

big component of muscle; important for making muscle, hormones, and protein; life cannot exist without them; made up of simple units, amino acids (AA); long chain of amino acids; 3 RNAs + DNA =

AA

more than 200 naturally occurring, only 20 common ___ ___ found in most proteins; 9-10 essential (depends on the species; need to be supplemented through the diet, not made in the body)

20 common, 9-10 essential

how many common AA and essential AA are found in most proteins?

essential components of AA

carboxyl group (-COOH) and animo group (NH2)

nitrogen

only present in proteins; 16% of proteins are this

R

different for every amino acids

carboxyl and amino groups

2 groups of proteins and amino acids

L isomers

all naturally occurring AA and most biologically active forms are what?

L amino acid

more active in the body than D-amino acid

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, and glycine (in some animals, ex. birds)

9-10 essential amino acids

lysine

limiting, if it its absent in diet no matter what, animals will die

arginine

essential AA for carnivores, cats and babies; classified as semi-essential in humans, goes away when you get older

length, order

the ___ of the AA chain and the order of AA within the chain determine the characteristics of the protein

peptide bond

linkage between one AA and another is called what?; link between 2 amino acids; only present in amino acids, absent in carbs

tripeptides, polypeptides

the chain of AA are elongated to ___ and ___ and eventually a complete protein molecule by addition of AA

polypeptides

more than 10 amino acids

karatins

has a lot of sulfur bonds making it a tough protein; proteins of wool, hair, feathers, horns, claws, beaks, nails, and hoofs; can be added if processed; very difficult to break in the body without enzymes; low nutrition value unless processed adequately; resistant to acid, alkali, heat and digestive enzymes