Term
| Describe cellular respiration |
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Definition
| Process in living cells where large food molecules (glucose) are broken down to release energy, water and carbon dioxide. |
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Term
| Equation for cellular respiration |
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Definition
glucose + oxygen water + carbon dioxide + energy
C6H12O6 + 6O2 -------------------> 6CO2 + 6H2O + ~38 ATP |
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Term
| Where does cellular respiration occur? |
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Definition
| Respiration occurs in the cytoplasm and mitochondria. |
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Term
| Explain the role of ATP in respiration |
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Definition
| Glucose is broken down in steps which are controlled by enzymes. The energy produced is stored in an ATP (adenosine tri-phosphate) molecule. ATP is the energy carrier in cells, it acts as a short-term biological battery. These ATP molecules can then breakdown to form ADP (adenosine di-phosphate) and a phosphate group and release energy. |
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Term
| What are the four stages of cell respiration? |
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Definition
| 1) Glycolisis, 2) Forming acetyl co-enzyme A 3) The krebs cycle 4) Electron transport chain |
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Term
| Describe where the first stage of respiration occurs and briefly explain what happens. |
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Definition
| Glycolysis occurs in the cytoplasm. Here glucose is broken down into pyruvate molecules and some ATP is also produced. If conditions inside the cell are anaerobic, pyruvate stays in the cytoplasm. In animal cells it forms lactic acid and in plant cells forms ethanol and carbon dioxide. Needs two ATP to occur, produces 4. NAD bonds with the hydrogen, and takes it to the mitcohondria. |
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Term
| Describe where the second stage of respiration occurs and briefly explain what happens |
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Definition
| Pyruvate from glycolisis is turned into and acetyl group. Cannot exist on it's own so bonds with co-enzyme A. Acetyl is transported to the matrix where it can be used in the Krebs cycle. |
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Term
| Describe where the third stage of respiration occurs and briefly explain what happens |
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Definition
| Occurs in the matrix of the mitochondria and is a complicated series of chemical reactions. It requires oxygen (aerobic) and 2ATP molecules are produced, as well as C02 as a waste product. Most importantly many NAD's bond with H2 to create NADH2. This hydrogen is transported to the electron transfer chain. |
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Term
| Describe where the fourth stage of respiration occurs and briefly explain what happens |
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Definition
| The respiratory chain occurs on the cristae of the mitochondria. Hydrogen from the Krebs cycle produces high energy electrons which move across the cristae and produce large amounts of ATP. The hydrogen joins with oxygen to produce water. |
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Term
| Describe some of the factors which affect the rate of respiration. |
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Definition
- Amount of oxygen present
- Amount of glucose or fat present
- Cells’ or bodies’ demand for energy
- Temperature, higher temperature, higher rate of respiration |
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