B8.2 - Respiration

Question 1

what are examples of energy consuming processes?

Answer 1

muscle contraction, protein synthesis, cell division and growth and maintenance of a constant body temperature.

Question 2

what does muscle contraction do?

Answer 2

This is to create movement of the organism, to move food along the alimentary canal; another example is the contraction of the uterus wall during childbirth.

Question 3

what does protein synthesis do?

Answer 3

Building up proteins from amino acids.

Question 4

what does cell division do?

Answer 4

This is to create more cells or replace damaged or worn out cells or to make reproductive cells.

Question 5

what does growth and the maintenance of a constant body temperature do?

Answer 5

to ensure that vital chemical reactions continue at predictable rates as the surrounding temperature varies.

Question 6

what is aerobic respiration?

Answer 6

Aerobic respiration is the chemical reaction in cells that use oxygen to break down nutrient molecules to release energy

Question 7

what is the word equation for aerobic respiration?

Answer 7

Glucose + oxygen → carbon dioxide + water

enzymes

Question 8

what is the balanced chemical equation for aerobic respiration?

Answer 8

C6H12O6 + 6O2 → 6CO2 + 6H2O

Question 9

what is anaerobic respiration?

Answer 9

It is the chemical reactions in cells which break down nutrient molecules to release energy without using oxygen.

Question 10

what is the word equation for anaerobic respiration in muscles?

Answer 10

Glucose → lactic acid (in muscles during vigorous exercise)

^lactic acid builds up in muscles and blood during vigorous exercise causing an oxygen debt.

Question 11

what are the stages of anaerobic respiration during exercise?

Answer 11

1. During vigorous exercise, the blood is unable to supply the muscles with enough oxygen for aerobic respiration
2. Therefore, the muscles respire anaerobically
3. The lactic acid build up creates cramps
4. The liver breaks down lactic acid with oxygen
5. After exercising, we breathe hard until we get enough oxygen to break down the lactic acid
6. This is called oxygen debt
7. Once lactic acid has been broken down, your breathing rate & rate of heart beat return to normal.

Question 12

what is the word equation of anaerobic respiration in yeast?

Answer 12

Glucose → alcohol + carbon dioxide

Question 13

what is the role of anaerobic respiration in yeast during bread making?

Answer 13

1. In brewing, yeast is dissolved in a warm liquid containing the sugar maltose
2. The yeast respires anaerobically by a process called fermentation
3. This process produces ethyl alcohol (ethanol) making the drink alcoholic and carbon dioxide which makes the drink fizzy.
4. In bread making yeast is mixed with water and sugar to activate it.
5. The mixture is added to flour to make dough and left in a warm place
6. The dough rises as the yeast respires and releases carbon dioxide which gets trapped in the dough
7. When the dough is cooked, the high temperature kills the yeast and evaporates any alcohol formed from brewing
8. Air spaces are left where the carbon dioxide was trapped, which gives the bread a light texture.

Question 14

what is the difference between aerobic and anaerobic respiration in energy levels?

Answer 14

Anaerobic respiration releases relatively less energy aerobic respiration because of the lack of oxygen, therefore, glucose cannot be broken down completely.