survey of biochemistry glycolysis
DESCRIPTION
SURVEY OF BIOCHEMISTRY Glycolysis. Announcements. Exam #2 on June 26 Chapters 7, 8, 11, 12, 14 Bring calculators Study Session with Vonda Thursday, June 26; 2-3:45 pm Boggs 228. Introduction to Glycolysis. Glycolysis: breakdown of sugars Primary start point = glucose - PowerPoint PPT PresentationTRANSCRIPT
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SURVEY OF BIOCHEMISTRY
Glycolysis
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Announcements
• Exam #2 on June 26– Chapters 7, 8, 11, 12, 14
• Bring calculators
• Study Session with Vonda – Thursday, June 26; 2-3:45 pm– Boggs 228
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Introduction to Glycolysis
• Glycolysis: breakdown of sugars
• Primary start point = glucose
• 10 enzymatic reactions
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Overview
Stage I of Glycolysis
• 2 ATP’s invested
• 1 Glucose is brokeninto 2 phosphorylated molecules
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Overview
Stage II of Glycolysis
• 4 ATP’s recovered
• 2 NADH’s produced
• GAP is converted to pyruvate
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Enzymes in GlycolysisStage I: Energy Investment
1. Hexokinase• Uses ATP
2. Phosphoglucose Isomerase [PGI]
3. Phosphofructokinase [PFK]• Uses ATP
4. Aldolase• Splits 6C into two 3C molecules
5. Triose Phosphate Isomerase [TIM]
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Enzymes in GlycolysisStage II: Energy Recovery
6. Glyceraldehyde 3-Phosphate Dehydrogenase• Uses NAD+ to form NADH
7. Phosphoglycerate Kinase [PGK]• Forms ATP (2 molecules)
8. Phosphoglycerate Mutase [PGM]
9. Enolase• Forms high energy molecule
10. Pyruvate Kinase [PK]• Forms ATP (2 molecules)
Classify theseon board
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Key Mechanisms
• Kinases: Transfer PO32- to substrate
• Phosphoglucose Isomerase
• Aldolase
• GAP Dehydrogenase
• Phosphoglycerate Mutase
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Example of Kinase Activity
Step 1: Hexokinase
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Phosphoglucose IsomeraseReaction Mechanism
Step 2
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PGI Reaction Mechanism
BaseCatalysis
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PGI Reaction Mechanism
AcidCatalysis
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PGI Reaction Mechanism
H+
Base catalyzes ring closure
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Glyceraldehyde 3-Phosphate Dehydrogenase
Step 6
Remember:Glycolysis produces 2 molecules of GAP, and therefore 2 molecules of NADH
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GAP Dehydrogenase Mechanism
Free Enzyme
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GAP Dehydrogenase Mechanism
Thiol Addition
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GAP Dehydrogenase Mechanism
Dehydrogenation
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GAP Dehydrogenase Mechanism
PhosphateBinding
Pi
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GAP Dehydrogenase Mechanism
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Phosphoglycerate Mutase
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Phosphoglycerate Mutase Mechanism
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Pyruvate Kinase
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What happens to pyruvate?
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PRS
• What is the maximum number of O2 molecules that hemoglobin can bind?
1. One2. Two3. Three4. Four
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PRS
• B cells mature in the ________.1. Thymus2. Bone marrow3. Muscle tissue4. Myosin
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PRS
• Oxygen binding to myoglobin results in what shaped curve?
1. Sigmoidal2. Hyperbolic3. Linear4. Sinusoidal
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PRS
• Which of the following amino acids is not in the catalytic triad of serine proteases?
1. Ser2. Thr3. His4. Asp
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PRS
• What is Km?
1. The catalytic efficiency2. The catalytic rate constant3. 1/2 Vmax
4. [S] at 1/2 Vmax