biochemistry glycolysis, glycogen metabolism

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biochemistry glycolys

Created Apr 17, 2012
by yvette27

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1	Through glycolysis, what is the net production of ATP?	2 molecules per 1 glucose molecule (but it uses 2 molecules ATP/1 molecule glucose)
2	How many molecules of pyruvate and NADH does one molecule of glucose produce?	2
3	What are the 3 pathways of glucose utilization in humans?	1) Glycogen 2) Oxidation via pentose phosphate pathway --> Ribose-5-phosphate 3)...
4	First phase of glycolysis Step 1	Glucose + ATP --> Glucose-6-P + ADP First priming reaction, catalyzed by enzyme hexokinase...
5	Hexokinase	First enzyme used in glycolysis pathway (all cells but liver) Add phosphate from ATP to glucose...
6	Glucokinase	First enzyme used in glycolysis pathway (just liver cells) Add phosphate from ATP to glucose...
7	First phase of glycolysis Step 2	Glucose-6-P --> Fructose-6-P Enzyme is an isomerase
8	phosphoglucoisomerase or just "isomerase"	Enzyme that catalyzes step 2 of first phase of glycolysis
9	First phase of glycolysis Step 3	Fructose-6-P + ATP --> Fructose-1,6-bisP + ADP Second priming reaction; major regulatory...
10	Phosphofructokinase 1 (PFK 1)	Enzyme catalyzed 3rd step of glycolysis,turning Fructose-6-P to Fructose-1,6-bisP thru the...
11	First phase of glycolysis Step 4	Fructose-1,6-bisP --> dihydroxyacetone + glyceraldehyde 3-P Catalyzed by aldolase Basically...
12	Aldolase	Enzyme in step 4 of glycolysis Cleaves fructose 1,6, bisP into dihydroxyacetone + glyceraldehyde...
13	First phase of glycolysis Step 5	Dihydroxyacetone P --> Glyceraldehyde P One of the products of the last reaction was glyceraldehyde,...
14	Triose phosphate isomerase	Dihydroxyacetone P --> Glyceraldehyde PIn step 5 of glycolysis. So now, 1 molecule of glucose...
15	Second phase of glycolysis Step 6	Glyceraldehyde-3-P + NAD+ + Pi --> 1,3-Bisphosphoglycerate + NADH + H+ Generates a high...
16	Glyeraldehyde-3P dehydrogenase	Removes H from Glyceraldehyde and replaces with Phosphate, yielding very high energy compound. Step...
17	Second phase of glycolysis Step 7	1,3-Bisphosphoglycerate + ADP --> 3-Phosphoglycerate + ATP First time ATP is formed!! Actually...
18	Phosphoglycerate kinase	Adds phosphate group to ADP, creating first molecule of ATP in glycolysis! Step 7 Transfers...
19	Second phase of glycolysis Step 8	3-phosphoglycerate -> 2-phosphoglycerate Just a change of position of P group Catalyzed...
20	Phosphoglycerate mutase	changes position of phosphate group in the 8th step of glycolysis pathway
21	Second phase of glycolysis Step 9	2-Phosphoglycerate --> Phosphoenopyruvate + H20 dehydration reaction catalyze by enolase
22	Enolase	catalyzes step 9 of glycolysis creates phosphoenopyruvate, an unstable high energy molecule
23	Second phase of glycolysis Step 10	phosphoenopyruvate + ADP --> pyruvate + ATP Catalyzed by pyruvate kinase.
24	Net reaction for glycolysis	Glucose + 2ADP + 2NAD+ + 2Pi --> 2 pyruvate + 2ATP + 2NADH + 2H2O (uses 2 ATPs to produce...
25	What happens to pyruvate?	Under aerobic conditions, ends up in TCA cycle Under anaerobic conditions, reduced to lactate...
26	A)What is the reaction to regenerate NAD+?B) What enzyme catalyzes it? C) What is this enzyme...	A) Pyruvate + NADH + H --> NAD+ + Lactate B) Lactate dehydrogenase C) Level of it in blood...
27	Buildup of what substance produces cramps in muscle? Why?	Lactate; it lowers the pH
28	What happens to lactate?	Can be oxidized back to pyruvate in other tissues and then used in TCA cycle Can be taken...
29	Regulation of glycolysis by ATP and AMP	Since role of glycolysis is to produce ATP, the [ATP] in the cell regulates it. *Presence...
30	Pyruvate kinase	Enzyme in last step (10) in glycolysis. phosphoenopyruvate + ADP --> pyruvate + ATP Activated...
31	What is the most serious glycogen storage disease?	Type I - von Gierke disease Primarily affects liver Leads to enlarged liver and...
32	Advantages of storing glucose as glycogen	1) Branching structure allows for rapid degradation
33	Two main tissues that store glycogen	Muscle and liver
34	Two enzymes involved in making glycogen	1) Glycogen synthase (highly regulated) 2) Branching enzyme
35	Two enzymes involved in degrading glycogen	1) Glycogen phosphorylase (highly regulated) 2) Debranching enzyme
36	Glucose-6-Phosphatase	In liver, removes phosphate group of glucose-6-phosphate producing free glucose that...
37	What hormone stimulates glycogen synthesis?	Insulin: stimulates glycogen synthase
38	What hormones stimulate glycogen degradation?	Glucagon: stimulates glycogen phosphorylase Epinephrine
39	High blood glucose leads to what?	High insulin and low glucagon --> Stimulates synthesis of glycogen, inhibits glycogen degradation Glucose...
40	Low blood glucose leads to what?	Low insulin and high glucagon --> Stimulates degradation of glycogen and inhibits synthesis Leads...
41	How is glycogen phosphorylase in/activated?	Phosphorylase kinase activates(adds Phosphate group) Protein Phosphatase deactivates (removes...
42	How is glycogen synthase de/activated?	Protein Phosphatase1 activates (removes Phosphate group) PKA deactivates : adds phosphate...
43	What does protein phosphatase-1 do?	Inactivates glycogen phosphorylase Activates glycogen synthase
44	What does PKA do?	cAMP dependent protein kinase A (PKA) deactivates glycogen synthase directly by adding phosphate...
45	What enzyme does the binding of glucagon and/or epinephrine activate?	Adenylate cyclase which makes cAMP
46	What enzymes does the binding of insulin activate?	Activates: Phosphodiesterase which degrades cAMP Activates: leads to series of rxns which...
47	What enzyme does cAMP activate (wrt glycogen metabolism)?	Protein Kinase A (PKA) which stimulates glycogen degradation
48	Three ways glycogen metabolism differs in muscle	1) No glucagon receptors . Because muscle does not release glycogen into the bloodstream (it...