1. Photosynthesis and Cellular Respiration Review- Answers

2. 1. Explain how energy flows between mitochondria and chloroplasts. Chloroplasts absorb light energy to produce glucose & O 2 by photosynthesis. Mitochondria take glucose in the presence of oxygen and split glucose apart – using the energy released to form ATP Chloroplasts use the CO 2 & H 2 O released by the mitochondria to perform photosynthesis so the cycle continues.

3. 2. Explain how the breakdown of ATP provides energy for the cell. When ATP is reduced to ATP, the high energy bond is released and that energy is then available for the cell to carry on its processes.

4. 3. Compare the following characteristics between aerobic and anaerobic respiration (you can use a table or chart): amount of ATP produced, site of activity and final products. Aerobic respirationAnaerobic respiration Amount of ATP produced36 ATP2 ATP Site of ActivityMitochondriaMitochondria in animal cells (lactic acid fermentation) Cytoplasm of yeast cells (alcoholic fermentation) Final ProductsCarbon dioxide, water, 36 ATP Lactic Acid & 2 ATP or alcohol & carbon dioxide 2 ATP

5. 4. Predict what would happen to a cell if its mitochondria failed to work. No powerhouse, no cellular respiration could occur The cell would die as no energy would be available to carry on its life processes.

6. 5. Explain why runners consume large amounts of carbohydrates a few days prior to a big race. Carbs are our primary energy source. Athletes must have lots of glucose on hand for cellular respiration to occur in their mitochondria so they consume lots of carbs a few days prior to the race to allow digestion of the carbs into glucose.

7. 6. If plant cells can make their own food why do they need mitochondria? Plant cells make glucose through photosynthesis. They also need mitochondria to allow cellular respiration to break down the glucose and release the energy (ATP) for cell processes.

8. 7. What kind of fermentation do yeast perform? Fully explain how this process can be useful to humans. Yeast cells carry on alcoholic fermentation. This type of fermentation is valuable for the making of bread, alcohol Can be an important fuel source as the alcohol still contains 93% of the energy and it burns cleanly (only producing carbon dioxide and water).

9. 8. Why is photosynthesis viewed to be the most important chemical process on the earth? Plants are the only organism that can capture sunlight energy and transform it into a useable organic molecule – glucose, through photosynthesis. Without this process all life would die.

10. 9. Compare alcoholic fermentation and lactic acid fermentation. Consider starting materials, and products and energy produced. (use a chart!!) Lactic Acid FermentationAlcoholic Fermentation Starting materialsGlucose ProductsLactic Acid C 3 H 6 O 3 Carbon dioxide, alcohol Energy released2 ATP

11. 10. What is the difference between ADP and ATP? ADP = adenosine diphosphate Adenosine + P + P ATP = adenosine triphosphate Adenosine + P + P + P