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23 Cards in this Set
- Front
- Back
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1. What type of cells can generate ATP from glycolysis?
Where are the enzymes of glycolysis? Does glycolysis need O2? |
All cells (every cell in body can use glucose to generate ATP)
Cytoplasm Anaerobic |
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2. How is NAD+ regenerated under anaerobic conditions?
How is NAD+ regenerated when O2 is present? |
Conversion of pyruvate to lactate
Regenerated in cytosol and e- of NADH are passed to e- transport chain of mitochondria |
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3. What is the net reaction of glycolysis?
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Glucose -> 2 Pyruvate
Use: 2 ATP and 2 NAD+ Form: 4 ATP and 2 NADH |
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4. What is the continuation in anaerobic glycolysis?
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2 Pyruvate -> 2 Lactate
Use: 2 NADH Form: 2 NAD+ |
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5. What are the two phase of glycolysis?
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1. Preparative Phase
glucose -> fructose 1,6 bisphosphate 2. ATP-generating Phase fructose 1,6 bisphosphate -> 2 pyruvate |
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6. What is the first step of glycolysis?
What is the enzyme involved? |
Glucose -> Glucose 6-phosphate
*Phosphorylation of glucose that traps it within the cells Hexokinase or glucokinase (liver) |
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7. What is a kinase?
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Breaks gama phosphate off ATP and moves it to another molecule
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8. What is the major regulatory point of glycolysis?
Why? |
Regulation is of phosphofructokinase (PFK-1)
First irreversible step that is committed to glycolysis Glucose 6-P can feed into glycogen synthesis, pentose phosphate pathway and others (not committed) |
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9. What reaction does PFK-1 catalyze?
What else does this reaction use? When is this enzyme greatly stimulated? |
Fructose 6-P -> Fructose 1,6-bisP
**Main control points Uses molecule of ATP When go from rest to exercise |
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10. In what reaction is NAD+ reduced?
What enzyme catalyzes this reaction? What other types of reactions does this enzyme catalyze? |
Glyceraldehyde 3-phophate -> 1,3 Bisphosphoglycerate
**Glyceraldehyde is both oxidized and phosphorylated Glyceraldehyde 3-phosphate dehydrogenase Enzymes catalyzes both oxidation and phosphorylation |
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11. Where does the first substrate-level phosphorylation occur?
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Transfer high energy phosphate from 1,3-bisphosphoglycerate to ADP
Phosphoglycerate kinase |
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12. What enzyme catalyzes the second substrate-level phosphorylation?
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Pyruvate kinase
**This is a control point |
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13. What do deficiencies in enzymes involved in glycolysis result in?
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Hemolytic anemias
**This is b/c RBC which is total dependent on glycolysis lacks sufficient ATP to operate ion pumps **Only have partial defects in glycolytic enzymes or else couldn't have life |
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14. What does fluoride inhibit?
What might this do? |
Enolase
Contribute to its anti-bacterial and anti-caries effect |
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15. How are e- from NADH transferred into the mitochondria since it cannot cross the inner mitochondrial membrane?
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Shuttle on glycerol 3-p or malate-asparate shuttle
In first step of both shuttles NAD+ is regenerated in cytosol and available for glycosis |
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16. In anaerobic glycolysis how is NAD+ regenerated?
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Reduction of pyruvate to lactate by lactate dehydrogenase
This is a readily reversible reaction depending on needs of cell |
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17. What types of tissues use anaerobic glycolysis?
Three characteristics.... |
1. Few or no mitochondria
2. Low O2 supply and/or poor vascularization (i.e muscles before warm up induced increase in blood flow) 3. When large amounts of ATP is need in aerobic tissues and ATP demand exceeds rate of ATP production by aerobic metabolism -simpler pathway so can go quicker |
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18. How does the heart use lactate?
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Convert lactate to pyruvate (lactate dehydrogenase)
Pyruvate then enters TCA cycle (aerobic metabolism) |
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19. How does the liver use lactate?
What is this called? |
Converts it back to glucose (gluconeogensis)
Glucose is then cycled back to muscle or RBC **Cori Cycle |
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20. What is lactic acidosis?
Why does it occur? |
Accumulation of lactic acid in the blood to levels that significantly decrease blood pH
Results from production of lactate in excess of its metabolism Occur due to... 1. Severe exercise 2. Heart attack (MI) 3. Anemia 4. Large tumor |
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21. How do anaerobic bacteria contribute to dental caries?
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Located in plague or tissue of teeth and produce lactic acid and other acids from glucose, fructose, and other dietary sugars
Acids produced by glycolysis w/in minutes of eating Acids produced in between meals using stored glucose (glycogen) **Acid promotes dissolution of tooth enamel that occurs in dental caries |
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22. Where is regulation of glycolysis?
What regulates it? |
First irreversible step
Phosphofructose Kinase (PFK -1) AMP activates it |
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23. In what types of muscles is this important in and how/why?
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Exercising muscles
AMP reflects need of muscle for ATP since it is produced by ADP (produce of ATP hydrolysis) Changes in AMP concentration is a sensitive indicator Increase AMP levels, stimulate PFK-1 |
