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35 Cards in this Set
- Front
- Back
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What is the committed step of glycolysis?
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PFK-1
phosphofructokinase-1 step |
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What is the purpose of glycolysis?
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oxidation of glucose
energy genreation (ATP and NADH) |
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where is the glycolysis located?
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cytoplasm
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How many reactions are there?
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10 reactions for glucose => pyruvate
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What are the regulated steps of glycolysis?
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1. glucokinase/hexokinase
2. phosphofructokinase-1 (committed step) 3. pyruvate kinase |
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Where and when does anaerobic glycolysis occur?
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RBCs (no mitochondria)
exercising muscle no O2 supply (ischemic stroke) |
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Glycolysis is broken down into three phases..what are they?
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investment phase: hydrolysis of 2ATP
spliting phase: 1x6Cs => 2x3Cs energy generation phase: all rxns repeated 2x per glucose 2x2 = 4 ATP per glucose net yield of AtP is 2 |
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Why do you need to phosphorylate the glucose?
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to trap it in the cell because it's not a substrate for a transporter
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____ is saturated at fasting blood glucose
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hexokinase
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Liver traps more glucose so what enzyme does it use to be more active?
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glucokinase
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What does the key step with PRK-1 do?
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fructose 6-P to fructose 1,6-biphosphate...requires ATP
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what enzyme is used to convert dihydroxyacetone phosphate into ___?
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triose phosphate isomerase
to GAP |
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NADH is a ____carrier
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electron
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how does arsenate work?
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competes with Pi...so no NADH therefore no 1,3BPG, no ATP => poisoning
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What is one way of producing ATP
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substrate-level phosphoryllation
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What is the net yield of aerobic glycolysis?
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2 pyruvate
2 ATP 2 NADH |
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What organs is the GAP shuttle present?
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brain and muscle
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What organs is the malate-aspartate shuttle?
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liver and heart
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GAP shuttle does what?
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transfers electrons and protons from NADH (cytoplasm) to FADH2 (inner mitochondrial membrane)
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Malate-Asparate shuttle does what?
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transfers electrons and protons from NADH (cytoplasm) to NADH (inner mitochondrial membrane)
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glucokinase is activated by
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glucose
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glucokinase is inhibited by
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glucose-6-P
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PFK-1 is inhibited by
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ATP and citrate
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PFK-1 is activated by
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AMP and fructose-2,6-BP
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pyruvate kinase inhibited by
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ATP
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Pyruvate kinase activated by....
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fructose 1,6-BP
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Induction by insulin of
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glucokinase, PFK-1, pyruvate kinase
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Repression by glucagon of
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glucokinase, PFK-1, pyruvate kinase
in liver only |
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Why are there additional mechanisms to regulate glycolysis in liver?
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glycolysis needs to be off during fasting and starvation so glucose produced not used by liver (futile cycle)
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In liver only, The PFK-2 and Fructose 2,6-biphosphatase is on the same enzyme...true or false?
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true
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glucagon stimulaes what?
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PKA: protein kinase A
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insulin stimulates what?
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protein phosphatase
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anaerobic glycolysis: pyruvate to what?
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lactate
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the energy yield from anaerobic glycolysis is
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2 ATP per glucose net yield
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lactic acidosis
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decrease arterial blood pH
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