biology chapter 12

Question 1

what is respiration

Answer 1

respiration is the breakdown of food molecules with the release of energy in living cells

Question 2

what is the chemical equation for aerobic respiration

Answer 2

C6H12O6 + 6O2 —> 6CO2 + 6H2O

Question 2

what are some examples of energy consuming processes in organisms

Answer 2

• cell division
• transmission of nerve impulses
• synthesis of protein from amino acids
• muscular contractions such as heartbeats and respiratory movements

Question 2

what is aerobic respiration

Answer 2

aerobic respiration is the chemical breakdown of food molecules in the presence of oxygen to release a large amount of energy. carbondioxide and water are released as a waste product

Question 2

what is the word equation for aerobic respiration

Answer 2

glucose + oxygen —> carbondioxide + water

Question 3

what is anaerobic respiration

Answer 3

anaerobic respiration is the chemical breakdown of food molecules in the absence of oxygen. anaerobic respiration releases much less energy per glucose molecules compared to aerobic

Question 4

what is anaerobic respiration like in yeasts

Answer 4

yeast releases ethanol and carbon dioxide as waste products during anaerobic respiration. anaerobic respiration in yeast is also called alcoholic fermentation

Question 5

what is the word equation for anaerobic respiration

Answer 5

glucose —-> ethanol + carbondioxide ( small amount of energy released)

Question 6

what is the chemical equation for anaerobic respiration

Answer 6

C6H12O6 —> 2C2H5OH + 2CO2

Question 7

what is the anaerobic respiration like in muscle cells

Answer 7

during vigorous muscular contractions, the muscle cells first respire aerobically. maximum aerobic respiration is unable to release energy quickly enough to meet the demand. if vigorous muscular contractions continue, extra energy has to be released. the muscles cells carry out anaerobic respiration to release this extra energy. lactic acid is formed in the process

Question 8

what is the word equation for anaerobic respiration in humans muscles

Answer 8

glucose —> lactic acid (+ small amount of energy released)

Question 9

how does the small amount of energy released in anaerobic respiration, together with the energy released in aerobic respiration help the muscles to contract

Answer 9

during vigorous muscles contractions, lactic acid builds up in the muscles and blood. since there is insufficient oxygen to meet the demands of the vigorous muscular contractions, the muscles are said to incur an oxygen debt.

Question 10

how can oxygen debt (or lactic acid acid) be removed

Answer 10

• continuation or deeper and faster breathing
• continuation of fast heart rate

Question 11

what are the similarities of aerobic and anaerobic respiration

Answer 11

• both processes release energy
• both processes involve the breakdown of food molecules
• both processes require enzymes, this is because the chemical reactions involved in the breakdown of food molecules are catalysed by enzymes

Question 12

what are the differences between aerobic and anaerobic respiration

Answer 12

aerobic respiration
- oxygen is required
- a large amount of energy is released
- carbondioxide and water are produced

anaerobic respiration
- oxygen is not required
- small amount of energy is released
- in human muscles, lactic acid is produced

Question 13

how do we know that living organisms respire

Answer 13

in aerobic respiration, oxygen is consumed, while carbon dioxide, energy and water are released. therefore, if we can show that an organism consumes oxygen and gives off carbondioxide and heat energy, we can say that it respires aerobically