Carbohydrates Flashcards
L1: Glycogen breakdown is catalyzed by _______.
Glycogen phosphorylase
L1: Glycogen synthase creates polymers of glycose with ____ linkages.
Alpha 1-4
L1: Insulin release by beta cells is stimulated by opening of ______ channels.
ATP-dependent Potassium
L1: Name key products of the pentose phosphate pathway.
NADPH, ribose-5-phosphate
L1: What % of the diet is accounted for by carbohydrates usually?
45-60%
L1: What is the effect of somatostatin on insulin release?
Decreases release
L1: What is the relative glycemic index for the following foods: croissant, coca-cola, raisin bran, whole grain bread?
Medium
L1: What is the relative glycemic index for the following foods: sourdough bread, apple juice, pumpernickel, oatmeal, pasta, basmati rice?
Low
L1: What is the relative glycemic index for the following foods: white bread, doughnuts, corn flakes, white rice?
High
L1: What percentage of total energy expenditure? Basal metabolic rate? Thermic effect of food?
75%; 8%
L1: Which intracellular proteins are activated to effect the metabolic actions of insulin?
Tyrosine kinases
L2: ______, involved in phosphorylation of glucose, has a high Km and Vmax
Glucokinase
L2: ______, involved in phosphorylation of glucose, has a low Km and Vmax
Hexokinase
L2: Depleted glutathione and Heinz bodies in RBCs are characteristic of a deficiency of ________.
Glucose-6-Phosphate Dehydrogenase
L2: FADH2 produced in the TCA cycle is produced in a step involving the production of _______.
Fumarate
L2: Fructose enters glycolysis at the level of _______.
Fructose-1,6-bis-phosphate
L2: Glucokinase is inhibited by _____-6-phosphate.
fructose
L2: Glucose is converted to glucose-6-phosphate by _____ in all cells of the body.
Hexokinase
L2: Glucose is converted to glucose-6-phosphate by ______ in the liver and pancreatic Beta cells.
Glucokinase
L2: GLUT__ transporters are insulin-______ and take up glucose in skeletal muscle and adipose tissue.
4; sensitive
L2: GLUT__ transporters are insulin-______ and take up glucose in the liver
2; independent
L2: GTP produced in the TCA cycle is produced in a step involving the production of ______.
Succinate
L2: Hexokinase is inhibited by _____-6-phosphate.
glucose
L2: In galactose metabolism, galactose is converted to ______, which may then be converted to glucose
UDP-galactose
L2: Name a key mediator in mitochondrial proliferation.
Peroxisome Proliferator-Activated Receptor Gamma Co-activator-1-alpha (PGC1-alpha)
L2: What byproducts are produced in the conversion of pyruvate to acetly CoA by PDH?
NADH, Carbon dioxide
L2: What effect do fatty acids have on PDH?
Allosteric Inhibition
L2: What effect does citrate have on glycolysis?
Inhition of PFK-1
L2: What enzyme is responsible for interconversion between glucose-1-phosphate and glucose-6-phosphate in glycogen metabolism?
Phosphoglucomutase
L2: What is the best way to measure total energy expenditure?
Doubly labeled water
L2: What is the effect of acetylcholine on insulin release?
Increases release
L2: What is the effect of AMP on glycogen breakdown?
Allosteric activation of glycogen phosphorylase
L2: What is the effect of calcium on glycogen breakdown?
Activates phosphorylase kinase, which phosphorylates glycogen phosphorylase
L2: What is the key enzyme in the pentose phosphate pathway?
Glucose-6-Phosphate Dehydrogenase
L2: What is the most accurate way to measure body composition?
DEXA (Dual Energy X-Ray Absorptiometry)
L2: What is the predominant form of starch found in basmati rice and bananas?
Amylose
L2: What is the predominant form of starch found in white bread, potatoes, and pastas?
Amylopectin
L2: Where does glycogen synthesis and breakdown occur?
Liver and skeletal muscle
L2: Which carbohydrate is often seen in beans, onions, asparagus, other vegetables, and probiotics?
Oligosaccharides
L2: Which cells produce GLP-1?
L cells of the intestinal mucosa
L2: Which enzyme in the TCA cycle is located in the inner mitochondrial membrane?
Succinate dehydrogenase
L2: Which gluconeogenic enzyme is found only in the liver and kidney?
Glucose-6-phosphatase
L2: Which intermediate in gluconeogenesis crosses the mitochondrial membrane to enter the cytosol?
Malate
L2: Which intracellular proteins are activated to effect the mitogenic actions of insulin?
MAP kinases
L2: Which two enzymes early in gluconeogenesis require ATP?
Pyruvate carboxylase, Phosphoenolpyruvate Carboxykinase (PEPCK)
L2: Which type of polysaccharide is found significantly in whole grains, vegetables, fruits, bran, celery, and beans?
Fiber
L2: Which type of starch is slowly absorbed and exists in a crystal structure (Ex. corn starch)?
Resistant starch
L3: ATP produced in glycolysis are produced in steps involving the production of _______.
3-Phosphoglycerate, Pyruvate
L3: Carbon dioxide produced in the TCA cycle are produced in steps involving the production of _______.
Alpha-ketoglutarate, Succinyl CoA
L3: NADH produced in glycolysis are produced in steps involving the production of _______.
Dihydroxyacetone Phosphate and Glyceraldehyde-3 Phosphate
L3: NADH produced in the TCA cycle are produced in steps involving the production of _______.
Alpha-ketoglutarate, Succinyl CoA, Oxaloacetate
L3: Name 4 actions of GLP-1.
Increase insulin release, Decrease glucagon release, decrease appetite, decrease GI motility
L3: Pyruvate kinase is inhibited by _______. (3)
Alanine, ATP, Glucagon signaling
L3: Which enzymes are involved in the TCA reactions that produce NADH?
Isocitrate dehydrogenase, alpha-keoglutarate dehydrogenase, malate dehydrogenase
L4: Name 5 required cofactors for PDH.
Coenzyme A, Thiamine Pyrophosphate, NAD (niacin derivative), FAD (riboflavin derivative), lipoate