C1.2 Cellular Respiration

Question 2

Outline why ATP is an efficient energy currency molecule?

Answer 2

Energy is formed through the formation of ATP from ADP and phosphate.

Then, in the presence of enzymes, ATP can participate in energy-requiring reactions. It does so through the hydrolysis of itself- forming ADP and phosphate. The energy itself that is released fron the reaction may be used for other metabolic processes (that require energy). Additionally, ATP forms phosphorylated (add a phosphate) intermediates when reacting with metabolites, hence making them more reactive in the process. The phosphate groups are released later, so both ADP and phosphate become available for reuse as metabolism continues.

Question 3

Distinguish between aerobic and anaerobic respiration

Question 4

Distinguish between cell respiration and gas exchange.

Answer 4

Gas exchange is a process where carbon dioxide and oxygen are exchanged at a surface such as the human alveoli. However, cell respiration is a chemical process whereby glucose loses an electron (is oxidized) in a step by step process to produce ATP

Question 5

Write down the word equations for aerobic and anaerobic respirations

Answer 5

Aerobic respiration

glucose+oxygen–> carbon dioxide+water+ATP

Anaerobic respiration

glucose—> lactate +ATP

Question 6

Identify 2 products of anaerobic respiration in the muscles.

Answer 6

Lactate and ATP

Question 7

Name 3 variables affecting rate of cell respiration

Answer 7

Firstly, metabolic rate of the cell. Muscle cells will require morr energy and therefore have higher rates of respiration.

Secondly, size of the organism. smaller organisms have alarger surface area compared to their sizr and thus have higher respiratory rates to allow for heat loss.

Lastly, pH. the release of carbon dioxide is controlled by enzymes, the temperature affects the rate of respiration by increasing it up to an optimum temperature.

temperature- as repiration is controlled by enzymes, temperature affects the rate of respiration vy increasing it up to an optimum temperature.

Question 8

Application of skills: Students should make measurements allowing for the determination of the rate of
cell respiration. Students should also be able to calculate the rate of cellular respiration from raw data that
they have generated experimentally or from secondary data.

Answer 8

Respuiration rate is measured by the uptake of oxygen per unit time with a manometer.

Question 9

Compare and contrast photosynthesis and respiraiton