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31 Cards in this Set
- Front
- Back
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What are four pathways of glucose utilization?
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Structural polymers, storage, oxidation via glycolysis, oxidation via pentose phosphate pathway
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How much ATP is produced by Glycolysis? in the electron transport chain? Maximum possible?
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2 ATP in glycolysis, 28-30 ATP in electron transport, 30-32 total
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Which ATP production is anaerobic? Aerobic?
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Glycolysis - aerobic
Electron transport - anaerobic |
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Where does glycolysis occur and what remains after glycolysis? What feeds into the krebs cycle, and where does the krebs cycle and electron transport occur?
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Glycolysis occurs in the cytosol, and produces pyruvate.
Pyruvate feeds into the Krebs cycle, krebs cycle and electron transport occur in mitonchondria |
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If oxygen is present what does pyruvate become? if anaerobic?
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aerobic - acetyl-CoA
anaerobic - Lactate |
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How much ATP does glycolysis requre? How much does it produce? What is the net yield?
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Requires 2 ATP, produces 4ATP, yields 2 ATP
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Other than ATP what does Glycolysis produce?
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2 NADH
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What is glucose broken down into during the first stage of glycolysis? and what do they become?
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2 phosphoglyceraldehydes -> 2 pyruvates
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What does Hexokinase do, and why is it important? Why is the product important?
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it irreversibly phosphorylates (high neg. delta G for reaction) glucose which commits it to metabolism in the cell b/c glucose 6-P can not cross the cell membrane...
branch point for carbohydrate metabolism |
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What are three irreversible reactions in glycolysis?
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Glucose --hexokinase-> Glucose 6-P
Fructose 6-P --Phosphofrucokinase-> Fructose 1,6, bis -P Phosphoenolpyruvate --Pyruvate kinase--> Pyruvate |
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What does Phosphofructokinase-1 do? What is it regulated by? In what pathway is it a rate limiting enzyme?
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1- converts Fructose 6-P to Fructose 1,6-bis-P
2. Inhibited by ATP, activated by AMP 3. Glycolysis |
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What converts Glucose to Glucose 6-P in the liver?
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Glucokinase
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Which of the 3 irreversible reactions produces ATP?
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Production of pyruvate
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What are the significant inputs and outputs of glycolysis?
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Inputs 2-ATP
Output - 4 ATP - 2 NADH - 2 Pyruvate |
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Which electron acceptor is necessary for glycolysis to continuse? How is the acceptor reoxidized?
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NADH
Through shuttle systems |
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In the absence of oxygen where does NADH deposit electrons? What does it produce?
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Deposits on Pyruvate to make lactate
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In the presence of oxygen what accepts electrons from NADH? and what does it do with them?
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Glycerol 3-P and malate-aspartate shuttles. Uses them in electron transport
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How many ATP is produced per NADH in Aerobic glycolysis?
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3 ATP
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Why are shuttles necessary in glycolysis?
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Because NADH cannot pass across the inner mitochondrial membrane
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Where is NAD located in the cell? Where is FAD located?
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NAD - cytosol
FAD - mitochondria |
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Which electron carrier system is more efficient? Which shuttle system involves FAD?
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Malate shuttle 2.5 ATP
G-3-P shuttle - 1,5 ATP G-3-P |
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In the glycerol 3-phosphate shuttle what accepts electrons from NADH? Which deposits electrons on what, which deposits electrons where?
Which enzyme catalyzes these steps? |
Glycerol 3-P accepts, deposits on FAD, which deposits in electron transport for a net gain of 1.5 ATP
glycerol 3-phosphate dehydrogenase |
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Which enzyme works in the malate-aspartate shuttle? Which electron acceptor is involved?
How many ATP are produced? |
Malate dehydrogenase
NADH 2.5 |
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What tissues rely on anaerobic metabolism?
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RBCs, Skin, Brain, Skeletal muscle. Low ATP demand and few capillaries
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Where is lactate reformed to glucose? How many Lactate molecules and ATP are required to reform glucose, and what is the process called? and what is the cycle called?
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Liver
2 lactate + 6 ATP make a glucose Gluconeogenesis Cori Cycle |
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What compounds does glycolysis produce that aid in biosynthesis? (4)
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ribose-5 phosphate for nucleotides
Serine from 3-phophosglycerate Alanine from pyruvate Fatty acids from triglycerides |
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What is a precursor for fatty acid biosynthesis, and in which tissues does it occur?
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Pyruvate
Liver, fat |
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What are three types of glycolytic regulation?
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Hormones (glucagon and Insulin)
Allosteric regulation ATP, AMP Long Term - gene expression |
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What allosteric factor is the key regulator of glycolysis?
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ATP
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What does AMPK stand for and what does it do in response to?
What about if active for a long time? |
Activated protein kinase
If ratio of AMP/ATP increases, it increases anabolic and catabolic ATP production, it regulates transcription |
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What is hexokinase inhibited by?
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Its product glucose 6-Phosphate
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