Respiration. Name.. Q.Anaerobic respiration happens in muscle cells and yeast cells. The equation describes anaerobic respiration in muscle cells. glucose lactic acid (a) How can you tell from the equation that this process is anaerobic?...... () (b) Exercise cannot be sustained when anaerobic respiration takes place in muscle cells. Explain why............. (2) (c) The diagram below shows an experiment to investigate anaerobic respiration in yeast cells. Page
What gas will bubble into Tube B? Tick one box. Carbon dioxide Nitrogen Oxygen Water vapour () (d) Describe how you could use tube B to measure the rate of the reaction in tube A............. (2) (e) Anaerobic respiration in yeast is also called fermentation. Fermentation produces ethanol. Give one use of fermentation in the food industry.... () (Total 7 marks) Q2.An athlete ran as fast as he could until he was exhausted. (a) Figure shows the concentrations of glucose and of lactic acid in the athlete s blood at the start and at the end of the run. Page 2
(i) Lactic acid is made during anaerobic respiration. What does anaerobic mean?...... () (ii) Give evidence from Figure that the athlete respired anaerobically during the run....... () (b) Figure 2 shows the effect of running on the rate of blood flow through the athlete s muscles. Page 3
(i) F how many minutes did the athlete run? Time =... minutes () (ii) Describe what happens to the rate of blood flow through the athlete s muscles during the run. Use data from Figure 2 in your answer............. (2) Page 4
(iii) Explain how the change in blood flow to the athlete s muscles helps him to run............................... (4) (Total 9 marks) Q3.Photosynthesis needs light. (a) Complete the balanced symbol equation f photosynthesis. light 6CO 2 +...... + 6O 2 (2) (b) A green chemical indicat shows changes in the concentration of carbon dioxide (CO 2) in a solution. The indicat solution is green when the concentration of CO 2 is nmal. The indicat solution turns yellow when the concentration of CO 2 is high. The indicat solution turns blue when the concentration of CO 2 is very low when there is no CO 2. The indicat solution does not harm aquatic ganisms. Students investigated the balance of respiration and photosynthesis using an aquatic snail and some pondweed. Page 5
The students set up four tubes, A, B, C and D, as shown in the table below. The colour change in each tube, after 24 hours in the light, is recded. Tube A Tube B Tube C Tube D Indicat solution only Indicat solution + pondweed Indicat solution + snail Indicat solution + pondweed + snail Stays green Turns blue Turns yellow Stays green (i) What is the purpose of Tube A? () (ii) Explain why the indicat solution in Tube C turns yellow. (2) (iii) Predict the result f Tube D if it had been placed in the dark f 24 hours and not in the light. Explain your prediction. Prediction... Page 6
Explanation... (3) (Total 8 marks) Q4.During exercise, the heart beats faster and with greater fce. The heart rate is the number of times the heart beats each minute.the volume of blood that travels out of the heart each time the heart beats is called the stroke volume. In an investigation, Person and Person 2 ran as fast as they could f minute. Scientists measured the heart rates and stroke volumes of Person and Person 2 at rest, during the exercise and after the exercise. The graph below shows the scientists results. (a) The cardiac output is the volume of blood sent from the heart to the muscles each minute. Cardiac output = Heart rate Stroke volume Page 7
At the end of the exercise, Person s cardiac output = 60 77 = 2 320 cm 3 per minute. Use infmation from Figure above to complete the following calculation of Person 2 s cardiac output at the end of the exercise. At the end of the exercise: Person 2 s heart rate =... beats per minute Person 2 s stroke volume =... cm 3 Person 2 s cardiac output =... cm 3 per minute (3) (b) Person 2 had a much lower cardiac output than Person. (i) Use infmation from Figure above to suggest the main reason f the lower cardiac output of Person 2. () (ii) Person was able to run much faster than Person 2. Use infmation from Figure above and your own knowledge to explain why. (5) (Total 9 marks) Page 8
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M.(a) no oxygen (is used) (b) muscles become fatigued / stop contracting because not enough energy is transferred (c) carbon dioxide (d) count the bubbles measure volume of gas in a given time (e) brewing / bread making allow other suitable use of fermentation in food industry [7] M2.(a) (i) without oxygen allow not enough oxygen igne air igne production of CO 2 igne energy Page 0
(ii) me / high / increased lactic acid (at end) allow approximate figures (to show increase) igne reference to glucose (b) (i).5 allow only.5 / ½ / one and a half (ii) increases at first and levels off igne subsequent decrease suitable use of numbers eg rises to 0 / by 9 (dm 3 per min) increases up to.5 (min) / levels off after.5 (min) (of x axis timescale) allow answer in range.4 to.5 after the first minute (of the run) (iii) supplies (me) oxygen supplies (me) glucose need me/faster once only f full marks allow removes (me) CO 2 / lactic acid / heat as an alternative f either marking point one two, once only f (me) respiration releases (me) energy (f muscle contraction) do not allow energy production f respiration [9] M3.(a) 6H 2O in the crect der C 6H 2O 6 Page
(b) (i) control do not accept control variable allow: to show the effect of the ganisms to allow comparison to show the indicat doesn t change on its own (ii) snail respires releases CO 2 (iii) turns yellow plant can't photosynthesise so CO 2 not used up but the snail (and plant) still respires so CO 2 produced [8] M4.(a) 5624 allow 2 marks f: crect HR = 48 and crect SV = 38 plus wrong answer / no answer only one value crect and ecf f answer allow mark f: increct values and ecf f answer only one value crect 3 (b) (i) Person 2 has low(er) stroke volume / SV / described eg Person 2 pumps out smaller volume each beat do not allow Person 2 has lower heart rate Page 2
(ii) Person sends me blood (to muscles / body / lungs) (which) supplies (me) oxygen (and) supplies (me) glucose (faster rate of) respiration transfers (me) energy f use igne aerobic / anaerobic allow (me) energy release allow aerobic respiration transfers / releases me energy (than anaerobic) do not allow makes (me) energy removes (me) CO2 / lactic acid / heat allow less oxygen debt less lactic acid made (me) muscle contraction / less muscle fatigue if no other mark awarded, allow person is fitter (than person 2) f max mark [9] Page 3