15 and/or 16 please QUESTION 15The formation of ethanol from pyruvate is an example ofO 1. an exergonie reactionO 2. an extra source of energy as the result of glycolysis.3. a fermentation process that takes place in the absence of oxygen.O 4. cellular respiration5. chemiosmosis.QUESTION 16Which of the following occurs during the carbon-fixation reactions of photosynthesis?O 1. Water is converted into hydrogen and water.O 2. CO2 and water are converted into sugars.O 3. Chlorophyll acts as an enzyme.O 4. Nothing occurs; the plant rests in the dark.5. Glucose and oxygen are reduced to CO2 and water.

Photosynthesis is a process of making organic compounds by using sunlight by green plants. It is endergonic process ,it means there is consumption of energy (ATP). It is anabolic process. On the other hand cellular respiration is a catabolic process and exergonic that is release energy during the process. Aerobic cellular respiration releases large amount of energy in the presence of oxygen and by oxidative phosphorylation. But in the absence of oxgen, anerobic respiration produces only 2ATP that is from glycolysis pathway which is a common pathway between aerobic and anerobic respiration or fermentation. In the absence of oxygen: Anaerobic fermentation: partial oxidation of glucose into ethanol and 2ATP NADH + H+ from glycolysis will acts as a reducing agent and it is regenerated into NAD+ by dehydrogenase enzyme , so that glycolysis can continue. Pyruvate is converted into organic products like ethanol , lactic acid and gases like carbon dioxide etc. Chemical reactions of fermentation by yeast: 1 Glucose ---> 2 ethanol + 2 carbon dioxide + 2ATP Answer 15. So we conclude that the 3rd option is the best suitable option. fermentation process that takes place in the absence of oxygen.Answer 16. Photosynthesis is done in two phases : Light reaction : capturing light energy and splitting water by green pigment chlorophyll. It forms assimilatory powers ,ATP and NADPH Dark reaction : fixing carbon dioxide into organic compounds ( sugars like sucrose, glucose ) by using assimilatory powers produced during light reaction. Photosynthesis reaction: 6CO2 ( carbon dioxide) + 6H2O ( water )→ C6H12O6 (glucose) + 6O2 Answer 16. Hence 2nd option is the correct answer 2) CO2 and water are converted into sugars.