Citric Acid Cycle and Feedstuffs Flashcards
What are the 3 ways pyruvate is used after glycolysis?
- Fatty acid synthesis.
- Lactate formation (Anaerobic conditions only).
- Citric acid/Kreb’s cycle (Most common).
Where does the citric acid cycle happen?
In the mitochondria, due to requiring aerobic conditions.
How is ATP created in the citric acid cycle?
The complete oxidation of acetyl-CoA, oxidation of NAD+ into NADH + H^+, and the oxidation of FAD+ into FADH_2.
What enzyme is required to convert pyruvate into acetyl-CoA?
Pyruvate dehydrogenase.
What co-factors are required to convert pyruvate into acetyl-CoA?
The oxidation of NAD+ into NADH +H^+. CoA goes in and CO2 comes out.
What enzyme is required to convert acetyl-CoA (in combination with oxaloacetate) into citrate?
Citrate synthase.
What co-factors are required to convert acetyl-CoA (in combination with oxaloacetate) into citrate?
H2O goes in. CoA comes out, now having been separated from acetyl.
What enzyme is required to convert citrate into isocitrate?
Aconitase.
What enzyme is required to convert isocitrate into alpha-ketoglutarate?
Isocitrate dehydrogenase.
What co-factors are required to convert isocitrate into alpha-ketoglutarate?
The oxidation of NAD+ to create NADH + H^+. The release of a CO2.
What enzyme is required to convert alpha-ketoglutarate into succinyl-CoA?
Alpha-ketoglutarate dehydrogenase.
What co-factors are required to convert alpha-ketoglutarate into succinyl-CoA?
The oxidation of NAD+ into NADH + H^+. CoA goes in and CO2 goes out.
What is important about the formation of succinyl-CoA?
At this point in the citric acid cycle, pyruvate is completely oxidized.
What enzyme is required to convert succinyl-CoA into succinate?
Succinyl-CoA synthetase.
What co-factors are required to convert succinyl-CoA into succinate?
ADP + Pi goes in. ATP and
CoA goes out.
What enzyme is required to convert succinate into fumarate?
Succinate dehydrogenase.
What co-factors are required to convert succinate into fumarate?
The oxidation of FAD+ into FADH_2.
What enzyme is required to convert fumarate into malate?
Fumarase.
What co-factor is required to convert fumarate into malate?
H2O goes in.
What enzyme is used to convert malate into oxaloacetate?
Malate dehydrogenase.
What co-factor is required to convert malate into oxaloacetate?
The oxidation of NAD+ into NADH + H^+.
How many ATP are produced from NADH+H^+?
25 from 10 H^+.
What is the ATP equivalency of NADH + H^+?
2.5 ATP.
How many ATP are produced from FADH_2?
9 from 6 H^+.
What is the ATP equivalency of FADH_2?
1.5 ATP.
At what 2 steps is the citric acid cycle regulated?
- Pyruvate dehydrogenase.
- Isocitrate dehydrogenase.
What is pyruvate dehydrogenase activated by?
Insulin, preventing gluconeogenesis.
What is isocitrate dehydrogenase regulated by?
Inhibited by an increase in the NADH + H^+: NAD+ ratio in the cell. Stops the reaction to prevent running out of NAD+.
What is citrate a substrate for?
Fatty acid synthesis.
What are the 2 mitochondrial membranes?
- Outer.
- Inner.
What is the function of the outer membrane?
Encompass the whole mitochondrion and forms the outer surface of the mitochondrion.
What is the function of the inner membrane?
Has transporters for different compounds. Controls what enters and leaves the mitochondrion.
What is the nutrient composition of a concentrate?
- Low in fiber.
- High in energy or protein.
What are energy concentrates?
Concentrates that are high in energy.
What are protein concentrates?
Concentrates that are high in protein.
What is the nutrient composition of a roughage?
- High fiber.
- Low nutrient density.
What are feed additives?
Any substance, other than concentrates and roughages, intentionally added to a diet/ration. ex: Vitamin, mineral, amino acid, drug, enzyme.
What family are cereal grains from?
The grass family.
What are cereal grains the primary energy source for?
- Non-ruminant animals.
- Ruminant animals.
What is the most important feed grain?
Corn.
Why is corn the most important feed grain?
- Highest DE content of all cereal grains.
- Overproduced.
- Inexpensive.
What is the energy profile of corn?
- High in starch.
- High in unsaturated fats.
- Roughly 4% oil.
- Low in fiber.
What is the protein profile of corn?
- 9% CP.
- Poor quality protein (insufficient amount of essential amino acids) because of the high zein (protein) content.
What is the mineral profile of corn?
- Low calcium.
- High in unavailable phosphorous, usually bound to phytate.
How is the unavailable phosphorous in corn made available to the animal?
The feed additive phytase.
What is the vitamin profile of corn?
- High vitamin A due to carotenoid pigments.
- Xanthophylls (pigment, not vitamin).
- Low in niacin (Vitamin B3).
Why are carotenoid pigments and xanthophylls important?
They provide the yellow color to chicken legs, egg yolks, and the yellowish-tinge to meat.
What is a deleterious factor associated with corn?
Aspergillus flavus.
What is aspergillus flavus?
A fungus that grows on live and stored corn that releases aflatoxin, a type of mycotoxin.
What are the preferred conditions for Aspergillus flavus growth?
Hot and humid conditions.
What affects does aflatoxin have on animals?
- Reduced feed intake.
- Diarrhea.
- Liver damage.
- Reduced growth.
What two cereal grains are good substitutes for corn?
- Sorghum.
- Millet.
What type of environment do sorghum and millet grow in?
Semiarid tropics.
*Corn cannot grow here.
What type of feed is millet commonly found in?
Bird seed.
What is the alternative name for sorghum?
Milo.
What is the energy profile of sorghum*?
*Millet has the same properties.
- Similar to corn.
- Requires processing (breaking the outer coating of the seed) to improve digestibility.
What is the protein profile of sorghum?
- 10% CP.
- Poor quality (low availability of amino acids).
What deleterious factor is associated with sorghum?
Condensed tannins in the seed.
How do condensed tannins affect animals?
- React with proteins and make them unavailable. Processing methods (chemicals) can overcome this.
- Astringent flavor that reduces feed intake.
What cereal grain is most commonly used for human consumption, and for animals only in excess?
Wheat.
What is the energy profile of wheat?
Similar to corn.
What is the protein profile of wheat?
13% CP.
Where is wheat commonly found when given to animals?
In pellets due to wheat gluten acting as a binding agent.
What is the deleterious factor of wheat?
Pentosans. (5-carbon sugar).
What affect do pentosans have on animals?
Causes diarrhea due to its poor digestibility.
What is the energy profile of barley?
Lower than corn.
What is the protein profile of barley?
12% CP.
What is the mineral profile of barley?
Phosphorous bound to phytate.
*Phytase needs to be added.
What is the deleterious factor of barley?
Contains beta-glucans.
What affect does beta-glucans have on animals?
- Reduces digesta flow rate and lipid absorption.
- Causes sticky excreta in poultry, blocking the vent and cloaca.
*Counteracted using glucanases.
Why are oats most commonly used for humans (horses being the exception)?
Oats are expensive.
What is the energy profile of oats?
- Low.
- High in soluble fiber.
- Can be processed (flaked, rolled) to improve digestibility.
What is the protein profile of oats?
- 12% CP.
- High quality protein.
What is the energy profile of rye?
Similar to barley and oats.
What is the protein profile of rye?
12% CP.
What is the deleterious factor associated with rye?
Ergot.
What is ergot?
A fungus that grows on rye grass and other grasses that produces compounds that cannot be combated by feed additives.
What does ergot do to animals?
- Necrosis of the extremities (hoof tips, ear tips, tail tips).
- Abortions.
- Agalactia.
- Reduced growth.
What are the deleterious factors of rye?
- Pentosans.
- Pectins.
What do pectins do to animals?
- Poor growth.
- Binds feedstuffs, limiting digestibility.
- Sticky excreta.
What seed is normally provided alongside cereal grains?
Buckwheat.
What is the energy profile of buckwheat?
Similar energy to corn.
What is the protein profile of buckwheat?
- 11% CP.
- High quality protein.
What deleterious factor is in buckwheat?
Fagopyrins.
What effect does fagopyrin have on animals?
It causes photosensitization in light-skinned animals, leading to skin lesions.
What animals are unaffected by most of the deleterious factors in carbohydrates?
Ruminants, due to the microbes in the rumen breaking down the compounds.
What is the carbohydrate profile of liquid molasses?
48% sugar.
What is the protein profile of liquid molasses?
3-4% CP.
What is the maximum % of the diet that liquid molasses can be?
30%, otherwise it has a laxative effect.
What % of the diet does liquid molasses normally compose?
2-5%.
Is liquid molasses fed to meet carbohydrate requirements?
No, it is fed for palatability.
What animals can develop molasses toxicity?
Ruminants.
How does molasses toxicity occur?
Molasses, when fed with inadequate forages causes the overproduction of butyrate by microbes, leading to ketosis. Causes blindness and incoordination.
What are dried by-products?
What is leftover after products for human consumption have been made.
What are 3 common dried by-products?
- Beet pulp.
- Dried citrus pulp.
- Dried bakery by-product.