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47 Cards in this Set
- Front
- Back
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Classification of carbs...based on..
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number of sugar moplecules in the compound
number of C atoms in a single sugar unit |
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monosaccharides... structure
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- many hydroxyl groups
open chain structures complex CH20 carbs + non CH20 molecules |
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Functional groups of monosaccharides=
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aldehydes and ketones
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__= monosaccharides that have same chemical formula but different structure ( D and L / alpha and beta)
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isomers
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__= isomer with orientation around C5; chiral concept
__= isomer with orientation around C1; ring formation produces a new chiral center |
D and L
alpha and beta |
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2 reactions of disaccharides..
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condensation and hydrolysis
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__= disac. reaction that is the formation of a new bond btw molecules w removal of H2O
___= disac. reaction that is the breaking of bonds btw 2 molecules with addition of H2O |
condensation
hydrolysis |
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2 linkages of disaccharides..
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- mammalian enzymes can hydrolyze some linkages ( alpha)
-some linkages require microbial enzymes for hydrolysis (beta) |
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polysaccharides..structure related to digestibility..
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starch- corn/potatoes; easily hydrolyzed
glycogen- meat byproducts/liver chains; easily digested cellulose- cotton fiber by-products; linear molecule; not readily available hemicellulose- not available |
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__= not a carb
gives strength to the plant |
lignin
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what is dietary fiber?
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lignin, cellulose
-polysac. not degraded by human enzymes |
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2 sources of enzymes for digestion and absorption of carbs=
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-pancreas- alpha amylase
- enzymes associated with intestinal epithelial cells |
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2 steps of digesting carbs
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intraluminal/ intestinal
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differences btw alpha amylase and lactase?
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alpha amylase- simple stomached greater than ruminants
- dogs greater than cats lactase- decreases with age |
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uses for glucose
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source of energy
glycogenesis lipogenesis lactose synthesis |
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__= formation of glycogen in liver, muscle
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glycogenesis
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__= synthesis of LCFA; occurs in adipose tissue in most domestic animals
-occurs in the liver of birds and humans -stored as a triglyceride |
lipogenesis
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__= maintenance of relatively constant blood glucose concentration
-too low=coma -too high= glucose in urine |
glucose homeostasis
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what body tissues use glucose?
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nervous system
muscle adipose RBC renal medulla retina fetus mammary glands |
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what hormones/body tissues are involved in glucose homeostasis?
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pancreas- insulin and glucagon
adrenal gland- cortex ( glucocorticoids) and medulla- epinephrine liver/muscles |
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absorptive vs post absorptive periods after eating?
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absorptive- immediately after eating up till several hours after eating
-nutrients being absorbed from the GI tract -body absorbs more glucose than immediately needed -increased insulin, decreased glucagon -glucose oxidized in body tissues and converted to glycogen in the liver and muscles -converted to fatty acids and stored as triglycerides postabsorptive- hours after eating -no longer absorbing glucose from the meal -body needs more glucose than absorbing at the moment -glycogenolysis in muscle -glucose stays in muscle -muscle removes less glucose from the blood lipolysis (breakdown of triglycerides) in body tissues -fatty acids released and used for energy by body tissues |
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absorptive period= time of ___
post absorptive period = |
hyperglycemia
hypoglycemia |
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what happens 18-24 hrs after eating?
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gluconeogenesis
occurs in liver and kidnesy changes in secretions of key hormones - increased glucocorticoids -increased glucagon and epinephrine decreased insulin |
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gluconeogenesis=
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the synthesis of glucose from noncarb precursors
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what occurs in the first stage of digestion of carbs?
2nd stage? |
-digestion into simple sugars
-relies on extracellular microbial enzymes 2nd stage -metabolism of simple sugars by the M.O. -produces ATP for microbial growth and other end products - |
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effects of a diet of forages?
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increase rumination, saliva production and buffering
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effects of a diet with increase grains in the diet?
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decrease rumination, saliva production, and buffering
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what is absorbed as end products of carb digestion?
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VFA's absorbed from the rumen
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what happens in high starch diets (high grain diets)
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-some starch will escape digestion in the rumen
-digestion of starch in the sm intesting -animal absorbs glucose from the diet |
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what is ruminal acidosis?
subclinical clinical associated problems prevention |
ruminal acidosis is a nutritional/mgt problem that occurs in animals on high grain diets or high silage diets, where the rate of acid production is greater than the ability to absorb or buffer the acids
subclinical- rumen pH <5.5, but not below 5.0 -decreased intake, decreased gain, poorer feed efficiency, decreased milk production; cyclic feeding associated problems- parakeratosis- damage to papillae and epithelial cells lining the rumen -liver abscesses -laminitis prevention- careful mgt (slow introduction of concentrates) -less grain -buffers (dairy cattle) -rumensin and tylan (beef cattle to prevent liver abscesses) |
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what are the end products of carb digestion?
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VFA's
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Which of the following is a disaccharide?
Choose one answer. a. glucose b. sucrose c. cellulose d. fructose . |
B
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Identify the substance that is a heteroglycan.
Choose one answer. a. hemicellulose b. starch c. glycogen d. cellulose |
A
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Choose the correct description of glycogen.
Choose one answer. a. composed of glucose units and found in the muscle of animals b. an example of an organic catalyst c. composed of glucose units and found in the seeds of plants d. given to ruminants as a source of nitrogen . |
A
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Out of the different linkages of glucose which one can be digested by mammalian enzymes?
Choose one answer. a. beta b. alpha c. gamma d. beta and alpha |
B
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Which of the following cell wall components decreases the total digestability of the plant?
Choose one answer. a. lignin b. cellulose c. hemicellulose d. pectin |
A
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Which of the following needs microbial enzymes for digestion?
Choose one answer. a. glycogen b. glucose c. starch d. pectin e. fructose |
D
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Which of the following is not part of the cell wall?
Choose one answer. a. cellulose b. lignin c. starch d. hemicellulose |
C
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If an animal has hypoglycemia, the body might respond by:
Choose one answer. a. increased glycogenolysis b. increased insulin release c. decreased gluconeogenesis d. decreased glucagon release |
A
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Where does glycogenesis occur?
Choose one answer. a. liver and muscle b. liver and kidneys c. adipose tissue d. muscle and kidneys |
A
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Gluconeogenesis occurs in 2 tissues. The 2 tissues are:
Choose one answer. a. liver and kidney b. adipose tissue and muscle c. muscle and kidney d. adipose tissue and liver |
A
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If glucose is completely oxidized then about _______% of the potential energy is captured in ATP.
Choose one answer. a. 30 b. 20 c. 50 d. 40 |
D
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Which of the following is TRUE about gluconeogenesis in ruminants?
Choose one answer. a. It is continuous. b. It is the highest after feeding. c. It uses absorbed nutrients - not body tissue. d. All of the above |
D
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When blood glucose level is high, the pancreas increases insulin production. Which of the following is NOT caused by increased levels of insulin?
Choose one answer. a. liver stores glucose in the form of glycogen b. muscle stores glucose in the form of glycogen c. kidneys store glucose in the form of glycogen d. adipose tissue stores glucose in the form of triglycerides |
C
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In practice all domestic animals are fed feedstuffs that contain carbohydrates. Which of the following is NOT true about these feedstuffs?
Choose one answer. a. They are a good source of energy. b. They can improve the health of the GI tract. c. They have been economical to feed. d. They are fed because there is a specified carbohydrate requirement. |
D
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What is the short-term response of a simple stomached animal to hypoglycemia?
Choose one answer. a. gluconeogenesis b. glycogenolysis c. lipogenesis d. glycogenesis |
B
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In the simple stomached animal, which of the following is NOT a major use for absorbed glucose?
Choose one answer. a. source of energy b. gluconeogenesis c. glycogenesis d. lipogenesis |
B
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