MODULE 5
RESPIRATION QUESTIONS
1.
The diagram shows anaerobic respiration in yeast.
(a)
Glucose [6C]
Complete the boxes in the diagram to show:
(i) the number of carbon atoms in each molecule of
fructose bisphosphate and in each molecule of pyruvate;
2ATP
(1)
2ADP
(ii)
the name of compound X.
(1)
Fructose bisphosphate
[...... C]
(b) Under anaerobic conditions, the oxidised form
of NAD is regenerated. Explain why this is essential.
Triose phosphate [3C]
(Type 1)
Phosphate
Triose phosphate [3C] .....................................................................................
(Type 2)
.....................................................................................
NAD
.....................................................................................
(1)
Reduced NAD
(c) In the reactions shown in the diagram, what is
the net gain of ATP molecules per molecule of
glucose? Explain how you worked out your answer.
2ADP
2ATP
.....................................................................................
.............................……………………………………
[...... C]
………………….........................................................
Reduced NAD
.....................................................................................
Pyruvate
...…………………………………………………...
NAD
(2)
(Total 5 marks)
CO 2
X: .................... [2C]
2
The diagram shows the main steps in the biochemical pathways involved in respiration.
Glycolysis
Anaerobic
respiration
Link
reaction
Krebs cycle
Oxidative
phosphorylation
(a)
(i)
Which step or steps take place on the cristae of the mitochondria?
.........................................................................................................................
(1)
(ii)
In which step or steps is carbon dioxide produced in an animal cell?
..........................................................................................................................
(1)
(b)
If a pond freezes over during the winter, goldfish can remain alive in the water under the ice. Explain
why they use the carbohydrate stores in their bodies much faster in these conditions.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
(2)
(c)
What is the main difference between the way in which ATP is produced by oxidative phosphorylation
and the way in which it is produced in photosynthesis?
...................................................................................................................................
...................................................................................................................................
(1)
(Total 5 marks)
3.
A preparation of mitochondria was made from liver tissue. Substances were added to this preparation and the
amount of oxygen in the preparation was monitored over a period of time. The diagram shows the trace
obtained and the times when the different substances were added.
Respiratory
substrate added
Time
A ADP added
Amount
of oxygen
remaining
in the
preparation
Time
B ADP added
Time
C ADP added
Time
(a)
Suggest why the respiratory substrate added to this preparation was a molecule from Krebs cycle and
not glucose.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
What additional substance, other than those mentioned on the diagram, would need to be added to this
preparation in order to get the results shown?
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
Explain:
(i)
why the amount of oxygen fell between lines A and B;
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
the shape of the trace after time C.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 5 marks)
4
Cockroaches are insects. The table shows the rates of oxygen consumption and carbon dioxide production of
cockroaches kept under different conditions.
(a)
Time after last
fed/hours
Temperature/°C
Rate of oxygen
consumption/
cm3 g–1 hour–1
Rate of carbon
dioxide
production/
cm3 g–1 hour–1
1
20
2.82
2.82
72
20
2.82
1.97
1
30
5.12
5.12
72
30
5.12
3.57
When the temperature is raised from 20°C to 30°C, the cockroach becomes more active and its
respiration rate and oxygen consumption increase. What causes the increase in respiration rate?
...................................................................................................................................
...................................................................................................................................
(1)
(b)
(i)
Calculate the Respiratory Quotient (RQ) of a cockroach kept at a temperature of 20°C, 72 hours
after it had last been fed. Show your working.
Respiratory Quotient =...........................
(2)
(ii)
The rate of carbon dioxide production by cockroaches is less 72 hours after they were last fed
than it is 1 hour after they were last fed. Explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 5 marks)
5.
(a)
Complete the table with a tick if the statement is true about the particular stage of respiration.
Statement
Stage of respiration
ATP produced
Glucose
pyruvate
Pyruvate
acetylcoenzyme A
Carbon
dioxide
produced
Reduced NAD
converted to
NAD
Krebs cycle
Electron carrier chain
(b)
(4)
The graph shows the volume of oxygen consumed and the volume of carbon dioxide released by a
small animal over a 15-minute period.
Oxygen
12
10
Carbon
dioxide
8
Volume
/mm 3
6
4
2
0
0
2
4
6
8
Time/minutes
10
12
14
16
Showing your working in each case, use the graph to calculate:
(i)
the rate of oxygen consumption;
Rate of oxygen consumption =.................................
(ii)
(1)
the respiratory quotient (RQ) of this animal over the 15-minute period.
RQ = ...........................................
(2)
(Total 7 marks)