1. CELL RESPIRATION
Topic 3.7
IB Biology
Miss Werba

2. CARBS, LIPIDS & PROTEINS 3.5 TRANSCRIPTION & TRANSLATION
TOPIC 3 - BIOCHEMISTRY
3.1 ELEMENTS & WATER
3.2
CARBS, LIPIDS & PROTEINS
3.3
DNA STRUCTURE
3.4
DNA REPLICATION
3.5 TRANSCRIPTION & TRANSLATION
3.6 ENZYMES
3.7 CELL RESPIRATION
3.8 PHOTOSYNTHESIS
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3. THINGS TO COVER Cell respiration
Substrates/products aerobic respiration
Substrates/products anaerobic respiration
Glycolysis & Kreb’s Cycle (basics)
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4. CELL RESPIRATION Command term = DEFINE
Cell respiration: The controlled release of energy from organic compounds in cells to form ATP
ATP = adenosine triphosphate
Chemical equation:
C6H12O6 + 6O2 + (36 ADP + 36 Pi) → 6CO2 + 6H2O + (36 ATP)
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5. GLYCOLYSIS Command term = STATE
Process: The breakdown of glucose (6 carbons) into two molecules of pyruvate (2 × 3C)
Location: Occurs in the cytosol (cytoplasm)
Energy yield: Results in a small yield of ATP (net gain = 2 ATP)
Aerobic/anaerobic: Either – not O2 dependent
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6. GLYCOLYSIS Command term = STATE
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7. ANAEROBIC RESPIRATION
3.5.3
ANAEROBIC RESPIRATION
Location: in the cytosol of the cell
Energy yield: a small yield of ATP (only the 2 ATP molecules from glycolysis)
Oxygen requirement: oxygen absent
Results in:
lactic acid (animal cells)
ethanol + CO2 (plant cells = fermentation)
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8. ANAEROBIC RESPIRATION
3.5.3
ANAEROBIC RESPIRATION
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9. AEROBIC RESPIRATION Location: in the mitochondria of the cell
3.5.3
AEROBIC RESPIRATION
Location: in the mitochondria of the cell
Energy yield: a large yield of ATP
2 ATP molecules from glycolysis
2 ATP molecules from Krebs Cycle
32 ATP molecules from the Electron Transport Chain
Oxygen requirement: oxygen present
Results in:
carbon dioxide (CO2) + water (H2O)
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10. 3.7
CELL RESPIRATION
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11. 3.7
CELL RESPIRATION
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12. Sample questions
Q1. Which process produces the most ATP per molecule of glucose? A. Anaerobic respiration in a yeast cell B. Aerobic respiration in a bacterial cell C. Glycolysis in a human liver cell D. The formation of lactic acid in a human muscle cell
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13. Sample questions
A1. B
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14. Sample questions
Q2. Compare how pyruvate is used in human cells when oxygen is available and when oxygen is not available.
(5 marks)
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15. Sample questions
A2.
aerobic cell respiration if oxygen available and anaerobic if unavailable;
pyruvate enters mitochondrion for aerobic respiration;
whereas pyruvate stays in the cytoplasm for processing under anaerobic conditions;
pyruvate converted aerobically into carbon dioxide and water;
whereas pyruvate converted anaerobically to lactate;
large ATP yield when oxygen available/from aerobic cell respiration;
no (further) ATP yield without oxygen;
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