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