1. Energy is required for respiration.
Answer: True.
Explanation: Cell respiration is a three-step process in aerobic organisms (Those that need oxygen): Glycolisis, Krebs cycle and oxidative phosphorilation. In glycolisis, glucose and other sugars are oxidize to pyruvic acid and energy (ATP) is needed in two of the reactions (to activate glucose and to activate fructose 6-phosphate).
2. Sugar and oxygen O2 are consumed in photosynthesis.
Answer: False.
Explanation: Photosynthesis is a process carry out by cianobacteria, algae and plants to produce sugar and oxygen from sunlight. This process has two phases:
a) Luminic phase. In this phase the energy from the sunlight is transported throught photosystems as electrons, oxygen and energy sustrates like NADPH are produced.
b) Calvin cycle. In this phase, sugars are synthetize from CO2 fixation and enzimatic activity in several steps, using NADPH produced in previous phase, as energy.
3. Carbon dioxide CO2 and water H2O are consumed in respiration.
Answer: False.
Explanation: In cell respiration, glucose and other sugars are completely oxidize to produce energy as ATP and as a residue, CO2. In this process, oxygen is consumed producing oxygen-reactive species that are neutralized by enzimes to form water (H2O).
