Exam 3 Flashcards
Nitrogen
- amino acids, or PROTEINS
- purines/Pyrimidines (DNA/RNA)
Dietary Essential Amino Acids
- amino acids that can not be synthesized at all or fast enough to meet the animals requirements
- must feed in diet
Monosaccharide
- 1 sugar (1 monomer)
Types
1) trioses(3 carbon sugars)
2) tetroses(4 carbon sugars)
3) pentoses(ribose)
4) ***hexoses(glucose) are nutritionally important
What is the distinction between lipid digestion/absorption process and the carbohydrate digestion/absorption process?
Carbohydrates: go to SI to be digested -> portal vein straight to liver -> rest of body
Lipids: go to SI to be digested -> lymphatic system -> rest of body -> liver
*lipids go to the liver last after rest of body and carbohydrates and starches go to the liver before rest of the body
Microbial Digestion of carbohydrates steps
1) bacteria attach to fiber components and secrete enzymes
- cellulase enzyme breaks down cellulose and other things we cant consume (cellulolytic bacteria)
- complex polysaccharides, simple sugars and starches are digested to yield sugars that are fermented to VFA (Amylolytic bacteria)
Lipid/fat digestion and aborption steps
lipids start in the small intestine to be digested -> go straight to lymphatic
system-> travel to the rest of the body-> lastly go to the liver
2 Types of Transport
1) Active Transport
- uses ATP to move nutrients
2) Passive Transport
- does not need ATP
- facilitated diffusion has a door or passageway that nutrient goes through on its own
Apolar amino acid
- R group contains no electron withdrawing groups
Disaccharides
- 2 sugars(glucose) molecules (2 monomers linked )
Types
1) maltose (glucose + glucose)
2) lactose(galactose + glucose, milk sugar)
3) sucrose (glucose + fructose, table sugar) - are all digestible by mammals
- contain the alpha 1-4 glycosidic bond which is digestible
4) cellobiose (fibrous portion from plants)
- the beta 1-4 (bond) linkage is not digestible by mammals
Can animal synthesize carbohydrates? From what are they synthesized (precursors) and what are the primary forms that are synthesized?
- they are synthesized from glycogen
- the primary form that is synthesized is glucose
What are the three essential fatty acids?
1) linoleic (most mammals)
2) linolenic (most mammals)
3) arachidonic acid (specific to cats)
Sources of cholesterol
1) de novo synthesis- creates cholesterol in the body
2) Diet
Digestion of carbohydrates in the Rumen Steps
- almost all carbohydrates are fermented in the rumen, glucose and carbs do NOT make it out of rumen
1) anaerobic fermentation of carbohydrates by microbes in the rumen
- the microbes produce cellulase for hydrolysis of cellulose (fibers)
2) produces Volatile Fatty acids such as acetate, propionate and butyrate
- provides a large portion of total energy supply
Easy explanation
- carbs are converted to VFA Abu microbes and then are absorbed into the blood circulation
How are triglycerides, or lipids digested/absorbed?
1) TRIGLYCERIDE starts in the SMALL INTESTINE where it is packaged by a MICELLE and crosses the APICAL MEMBRANE to enter enterocyte
2) triglyceride then forms a CHYLOMICRON in order to cross the BASOLATERAL MEMBRANE and enter into the lymphatic system
- there are villis on the small intestine which are surrounded by a brush border
Proteins
- polypeptide chain made up of amino acids arranged in a specific sequence provided for in the genetic code
4 levels of structure
- primary
- secondary
- tertiary
- quaternary
Other types of hexoses (glucose)
1) Mannose
- found after hydrolysis of plant mannosans and gums, legumes
2) Galactose
- component of milk sugar (lactose)
- may be metabolized to glucose
3) Fructose
- found in fruits, cane sugar, and honey
Glucose
- most important monosaccharide
- primary form of sugar used for energy
- component of starch, cellulose and glycogen
- formed from carbohydrate digestion in monogastrics BUT NOT in ruminants
Why is Nitrogen balance so important?
- if feed too much nitrogen can not utilize it all and will have to excrete it
1) nitrogen waste is not good for the environment (environmental concerns)
2) animal is at optimal health when has proper nitrogen balance (health and production status)
3) it is a waste of money to overfeed nitrogen
Polar amino acid
- R group contains an electron withdrawing group
Cellulolytic bacteria
- FIBER DIGESTERS
- prefer pH 6-7
- produce ACETATE, propionate, butyrate, CO2
- produce cellulase (converts cellulose to glucose)
- predominate in animals fed forage (high fiber diets)
What are the animal tissues that require glucose?
1) the brain
2) fetal tissue
Life Essential Amino Acids
- Vincent Du Vigneaud
- those amino acids so essential to metabolic function and life that the body must synthesize them itself
Example of de novo synthesized
What are Lipids?
- heterogenous groups of compounds related by the following physical properties:
1) have Aliphatic Carboxylic Acids
2) contain C,H,O
3) MIGHT contain P, N
Fibrous Proteins
- water INSOLUBLE
- LINEAR
Ex: collagen, elastins, keratin
3 Excretory Forms of Waste Nitrogen
1) Ammonia
- direct urinary excretion
2) urea
- urea cycle (liver)
3) Uric Acid
- waste product of purine metabolism
Carbohydrate Digestive Enzymes Chart give origin and substrate, action (what they digest) - Amylolytic Enzymes 1) salivary amylase 2) pancreatic amylase 3) maltase, isomaltase 4) lactase 5) sucrase 6) oligoglucosidase
1) origin= saliva action/substrate= starch, dextrins 2) origin= pancreas action/substrate= starch, dextrins 3) origin= SI action/substrate= maltose, isomaltose 4) origin= SI action/substrate= lactose 5) origin= SI action/substrate= sucrose 6) origin= SI action/substrate= oligosaccharides
Chylomicron
- gets triglycerides out of enterocyte and into the lymphatic system
Monosaccharide Absorption
- with the exception of newborn animals (first 24 hours), no di, tri or polysaccharides are absorbed
- absorbed primarily in the duodenum and jejunum
- limited absorption in the stomach and LI
Why can ruminants eat hay, but monogastrics can not ?
- hay is high in fiber therefore a monogastrics stomach can not digest it
- ruminants can digest hay because they have microbes that produce cellulase to break down cellulose and convert it to VFA to be absorbed into the blood stream
What are the three Volatile Fatty Acids that ruminants produce when they breakdown glucose?
1) acetate
- energy and fatty acid synthesis
2) propionate
- energy and gluconeogenic (glucose synthesis)
3) butyrate
- energy and rumen epithelial cells convert to ketone
Acidic
- amino acid has an extra ionized carboxyl group at physiological pH
What can be absorbed by the GI tract
- monosaccharides only
Aliphatic amino acid
- R group contains only carbon and hydrogen
Types of lipids
1) Simple Lipids
- fats (triglycerides)
- waxes
2) Complex Lipids
- phospholipids
- glycolipids
- lipoproteins
3) cholesterol
Zwitterion
- amino acid that is ionized but has no net charge
Glucose is the major metabolic fuel for all mammals except the ruminant why?
- it would be inefficient because ruminants have microbes (microbial fermentation) that break down glucose into volatile fatty acids
- therefore glucose does not go directly into the blood stream the volatile fatty acids do
(Glucose+microbes)= VFA
Fatty acid as aliphatic carboxylic acid properties and types
- aliphatic carboxylic acids that contain ONLY C, H, O
Types:
1) saturated
- fatty acid contains no C=C double bonds
2) monounsaturated
- fatty acid contains 1 C=C double bond
3) polyunsaturated
- fatty acid contains 2 or more C=C double bonds
List of Essential Amino Acids
PVT TIM HALL
1) phenylalanine
2) valine
3) tryptophan
4) threonine
5) isoleucine
6) methionine
7) Arginine
8) Leucine
9) Lysine
*essential amino just for cats is TOURINE
Cholesterol is a precursor to (can be made into)
1) steroids
- all steroid hormones in the body are made from cholesterol
2) bile acids
Monogastrics vs Ruminant Digestion/Absorption of Carbohydrates
Monogastrics (mammals)- have digestive enzymes like lactase that can break down glucose(carbohydrates) in the small intestine and be directly absorbed into blood circulation
Ruminants- have microbes that break down carbohydrates (glucose) during microbial fermentation and they are converted into Volatile Fatty Acids which are then absorbed into the blood stream
- glucose is not directly absorbed into blood stream
(Glucose + microbes) = VFA
Amylolytic Bacteria
- STARCH digesters
- prefer pH 5-6
- produce propionate, butyrate and sometimes LACTATE
- predominate in animals fed grain diets
- lactate produced can sometimes be harmful to the ruminant if there is a rapid change to grain diet (lactic acidosis- rapid decrease in pH)
Amino acid availability and factors affecting availability
- related to all factors affecting amino acid utilization from the time of ingestion to the time of assimilation into the body
External factors:
1) protein type
2) processing effects
3) amino acid balance of the diet
4) other nutrients in the diet
5) antiquality factors
Internal factors
1) efficacy of digestive tract
2) Catabolic/Anabolic Hormone
3) Physiological Status
4) Microbial Digestion and Synthesis
Heterocyclic
- ring structure of amino acid contains within the ring an atom other than carbon
Aromatic
- amino acid contains benzene ring structure
For production of w6 and w3 polyunsaturates must have a dietary source of
1) linoleic acid
2) linolenic acid
How is active transport for glucose accomplished? draw and steps
1) glucose and sodium begin in the SMALL INTESTINE and travel through the SGLT SYMPORT using ACTIVE TRANSPORT across the APICAL MEMBRANE and transport into the ENTEROCYTE (cells)
2) GLUCOSE leaves the enterocyte by going through the GLUT UNIPORT using PASSIVE TRANSPORT across the BASOLATERAL MEMBRANE into the BLOOD STREAM
3) SODIUM leaving from the enterocyte and K+(POTASSIUM) leaving from the blood stream travel across the BASOLATERAL MEMBRANE through a ANTIPORT
Globular Proteins
- water SOLUBLE
- spherical
Ex: Albumin and Globulins
3 Transport mechanisms an animals cells can use to move nutrients across membranes
1) symport- enter together in same direction
2) antiport- one enters, one exits opposite directions
3) uniport- only one goes in or out
Basic
- amino acid has an extra ionized amino group at physiological pH
Micelles function in a monogastric vs in a ruminant
Micelles purpose is to get the triglycerides from the small intestine into the enterocyte by packaging the triglycerides
Micelles makeup in Monogastric:
1) monoacylglyceride **
2) free fatty acids
3) bile salts
4) cholesterol
5) fat soluble vitamins
Micelles makeup in Ruminant:
1) lysolecithin***
2) free fatty acids
3) bile salts
4) fat soluble vitamins
5) little to no monoacylglyceride (replaced)
Why can ruminants digest hardier fibers that mammals can not?
- ruminants have microbes that make cellulase and they can break the 1-4 beta linkage in non digestible dissacharides
What does this mean 18:2🔺^9,12 and w6(omega)
What If there was 14:0
18 is the number of total carbons on the chain
2 is the number of double bonds
9,12 are the carbons where the double bonds are located counting from the carboxylic acid
——
Omega 6 tells us that there is a double bonded carbon on the 6th carbon counting from the opposite side of the carboxylic acid, the methyl side
- only tells us the first double bond on the chain
———
14 total number of carbons
0 tells us there are No double bonds
Which can utilize VFAs for energy better carnivores or hind gut fermenters?
Carnivores bacteria produces small quantities of cellulase so has limited anaerobic fermentation
HINDGUT FERMENTERS (horses and rabbits) can utilize large quantities of cellulose, the cecum and colon (LI) contain bacteria that produces cellulase - increased capacity to utilize VFAs for energy
Nutritional value of a protein and example factors affecting quality
- ability of a protein to meet the essential amino acid requirements of the animal
Ex:
- amino acid balance
- digestibility
- absorption
- antiquality factors
- health of animal
- caloric intake
Where is a brush border and what is its function?
- it surrounds the villis on the small intestine
- it is composed of water and mucins
- it’s function is to keep out fat that isn’t packaged in micelles and microbes
