Living Cells

Respiration & Photosynthesis

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1) Energy is measured in units called .
2) Glucose is the main source of in a living cell. the chemical energy stored in glucose is released by a series of reactions controlled by enzymes. This biochemical process is called and some of the energy is released as .
3) ATP is a high-energy compound able to release and energy when it is required for cellular processes.
4) ATP is regenerated from and inorganic phosphate using energy released from the breakdown of during respiration.
5) is a respiratory pathway common to aerobic and anaerobic respiration. It involves the breakdown of glucose to acid.
6) In the presence of oxygen, respiration occurs. In plant and animal cells, water and CO2 are formed and molecules of ATP are produced per molecule of glucose.
7) In the abosence of oxygen, respiration occurs. In animal cells, pyruvic acid is reversibly converted to acid which causes muscle . In plant cells, pyruvic acid is irreversibly converted to and CO2. In each case only molecules of ATP are produced per molecule of glucose.
8) Green plants use sunlight as their source of energy to make food. This process is called . It is the means by which the raw materials and CO2 are converted to the end products glucose and by a series of controlled reactions.
9) During the first stage of photosynthesis called , light energy is captured by green in chloroplasts and used to split molecules of water into oxygen and . Some of the energy is used to regenerate from ADP and inorganic .
10) During the second stage of photosynthesis, called carbon , hydrogen from photolysis is combined with to form glucose. This process requires energy supplied by ATP.
11) Some glucose molecules formed during photosynthesis are converted to and stored; others are converted to and become part of the cell .
12) Photosynthesis is affected by environmental factors such as intensity, CO2 concentration and . Its rate is therefore by whichever of these factors is in short supply.