11.The diagram below shows possible pathways for the breakdown of glucose in various cells.

(a)State the names of processes Q and R.Q:..................................................................................................................................(1)R:..................................................................................................................................(1)(b)Deduce the names of substances A and D.A:..................................................................................................................................(1)D:..................................................................................................................................(1)(c)State the organelle in which process R takes place................................................................................................................................................(1)(Total 5 marks)

2.At the start of glycolysis, glucose is phosphorylated to produce glucose 6-phosphate, which is converted into fructose 6-phosphate. A second phosphorylation reaction is then carried out, in which fructose 6-phosphate is converted into fructose 1,6-bisphosphate. This reaction is catalyzed by the enzyme phosphofructokinase. Biochemists measured the enzyme activity of phosphofructokinase (the rate at which it catalyzed the reaction) at different concentrations of fructose 6-phosphate. The enzyme activity was measured with a low concentration of ATP and a high concentration of ATP in the reaction mixture. The graph below shows the results.

(a)(i)Using only the data in the above graph, outline the effect of increasing fructose 6-phosphate concentration on the activity of phosphofructokinase, at a low ATP concentration.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(ii)Explain how increases in fructose 6-phosphate concentration affect the activity of the enzyme.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)

(b)(i)Outline the effect of increasing the ATP concentration on the activity of phosphofructokinase.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(ii)Suggest an advantage to living organisms of the effect of ATP on phosphofructokinase...........................................................................................................................................................................................................................................................................(1)(Total 7 marks)

3.Explain the process of aerobic respiration including oxidative phosphorylation.(Total 8 marks)

4.(a)Define the term species..............................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(b)List three kingdoms into which living organisms are classified...............................................................................................................................................................................................................................................................................................(1)(c)The seven levels used in hierarchy of taxa are:Kingdom, Phylum, Class, Order, Family, Genus and Species.State which two are used in the binomial system of nomenclature................................................................................................................................................(1)(Total 4 marks)

5.Of the following products, which is produced by both anaerobic respiration and aerobic respiration in humans?I.PyruvateII.ATPIII.LactateA.I onlyB.I and II onlyC.I, II and IIID.II and III only(1)

6.Which is not a product of the Krebs cycle?A.CO2B.NADH + H+C.PyruvateD.ATP(1)

7.How many ATP molecules (net yield) are produced per molecule of glucose as a direct result of glycolysis?A.2B.4C.10D.38(1)

8.What happens during muscle contraction?A.Both actin and myosin filaments shorten.B.Na+ ions are taken up by the sarcoplasmic reticulum.C.The actin and myosin filaments slide over each other.D.Cross bridges remain attached to the filaments.(1)

9.Explain the similarities and differences in anaerobic and aerobic cellular respiration.(Total 8 marks)

10.Anaerobic respiration occurs in the absence of oxygen while aerobic respiration requires oxygen.(a)State one final product of anaerobic respiration................................................................................................................................................(1)(b)Complete the table showing the differences between oxidation and reduction.

OxidationReductionElectrons gained orlost

Oxygen or hydrogen gained or lost

(2)

(c)The structure of a mitochondrion is shown in the electron micrograph below.

Name the parts labelled A, B and C and state the function of each.Part A:Name: ..................................................................................................................Function: .............................................................................................................Part B:Name: ..................................................................................................................Function: .............................................................................................................Part C:Name: ..................................................................................................................Function: .............................................................................................................(3)(Total 6 marks)

11.(a)(i)Identify the cell organelle shown in the micrograph below.

.....................................................................................................................................(1)(ii)Identify the structure labelled I above and explain how it is adapted for the organelle to function efficiently....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(3)(b)Describe the role of acetyl CoA in the metabolism of lipids.............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(Total 6 marks)

12.The rate of carbon dioxide uptake by the green succulent shrub Aeonium goochiae can indicate the amount of photosynthesis taking place in the plant. This rate was measured at 15C and 30C over a 24-hour period. The units of carbon dioxide absorption are mg CO2 h1.The results are shown below. The centre of the graph corresponds to 2 mg CO2 h1 and the outer ring is +2.5mg CO2 h1.

[Source: adapted from www.biologie.uni-hamburg.de/b-online/e24/9.htm](a)Identify a time that carbon dioxide uptake was the same at both temperatures................................................................................................................................................(1)(b)State the maximum rate of carbon dioxide uptake at 15C................................................................................................................................................(1)

(c)Compare the rate of carbon dioxide uptake at each temperature in daylight and darkness..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(3)(d)Suggest why the carbon dioxide uptake may at times be negative...............................................................................................................................................................................................................................................................................................(1)(Total 6 marks)

13.Which way do the protons flow when ATP is synthesized in mitochondria?A.From the inner matrix to the intermembrane spaceB.From the intermembrane space to the inner matrixC.From the intermembrane space to the cytoplasmD.From the cytoplasm to the intermembrane space(1)

14.What accumulates in the inter-membrane space of the mitochondrion during electron transport?A.ATPB.ElectronsC.Protons (hydrogen ions)D.Oxygen(1)

15.(a)State two functions of proteins with a named example of each..............................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(b)Explain chemiosmosis as it occurs during cell respiration............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(Total 4 marks)

16.Biosphere 2, an enormous greenhouse built in the Arizona desert in the USA, has been used to study five different ecosystems. It is a closed system so measurements can be made under controlled conditions. The effects of different factors, including changes in carbon dioxide concentration in the greenhouse, were studied. The data shown below were collected over the course of one day in January 1996.

[Source: http://www.Ideo.columbia.edu/martins/climate_water/labs/lab6/labinstr6/html](a)(i)Identify the time of day when the sun rose......................................................................................................................................(1)

(ii)Identify the time of minimal CO2 concentration......................................................................................................................................(1)(b)Determine the maximum difference in the concentration of CO2 over the 24-hour period...............................................................................................................................................................................................................................................................................................(1)(c)Suggest reasons for changes in CO2 concentration during the 24-hour period............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(Total 5 marks)

17.What is the sequence of stages during the conversion of glucose into pyruvate in glycolysis?A.lysis phosphorylation of sugar oxidationB.lysis oxidation phosphorylation of sugarC.phosphorylation of sugar lysis oxidationD.phosphorylation of sugar oxidation lysis(1)

18.(a)State two products of the process of glycolysis...............................................................................................................................................................................................................................................................................................(1)

(b)Explain the significance of polar and non-polar amino acids within the cell..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(3)(Total 4 marks)

19.The respiratory quotient (RQ) is a measure of the metabolic activity of an animal. It is the ratio of CO2 produced to O2 consumed. In general, the lower the RQ value the higher the energy yield. The RQ is dependent on the diet consumed by the animal. The following table lists the typical RQ values for specified diets.DietRQLipid0.71Carbohydrate1.00Protein0.74[Source: Walsberg and Wolf, Journal of Experimental Biology, (1995), 198, pages 213219. Reproduced by permission of The Company of Biologists Ltd]In an experiment to assess RQ values for house sparrows, the birds were fed a diet of pure mealworms (beetle larvae) or millet (a type of grain).

The graph below shows the RQ values of a house sparrow fed on a high carbohydrate diet (millet) and a high lipid diet (mealworms).

[Source: Walsberg and Wolf, Journal of Experimental Biology, (1995), 198, pages 213219. Reproduced by permission of The Company of Biologists Ltd](a)Compare the RQ values for millet and mealworms between 1 hour and 6 hours after feeding............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)The expected RQ value for house sparrows metabolizing millet is 0.93. The expected value when metabolizing mealworms is 0.75.(b)Explain why the expected RQ values for millet and mealworms are different............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)

(c)Suggest reasons for(i)the high initial RQ values for house sparrows fed on millet...........................................................................................................................................................................................................................................................................(1)(ii)the rapid fall in RQ values for house sparrows fed on millet...........................................................................................................................................................................................................................................................................(1)(Total 6 marks)

20.Which of the following produce ATP in mitochondria?A.The movement of protons from the matrix to the intermembrane spaceB.The movement of protons from the intermembrane space to the cytoplasmC.The splitting of water molecules and the movement of electrons to oxygenD.The movement of protons from the intermembrane space to the matrix(1)

21.How many molecules of acetyl CoA (ethanoyl CoA) does the oxidation of the fatty acid stearic acid produce?

A.2B.6C.9D.18(1)

22.Explain the process of aerobic cellular respiration.(Total 8 marks)

23.(a)Q: anaerobic respiration / fermentation;R: aerobic respiration / Kreb's (citric acid) cycle;2(b)A: pyruvate / 3-oxopropanoate;D: carbon dioxide;2(c)mitochondrion;1[5]

24.(a)(i)increasing fructose 6-phosphate concentration (initially) causes an increasein activity;activity levels out / remains constant as (substrate) concentration continues to rise;2(ii)more collisions with active site as concentration rises;at high substrate levels all active sites are occupied so no further increase in rate / enzyme working at maximum rate;2(b)(i)decreases activity;at all fructose 6-phosphate concentrations;most effect at intermediate fructose 6-phosphate concentrations / little differenceat high fructose 6-phosphate concentrations;ATP acts as an inhibitor;2 max(ii)end-product inhibition;respiration rate decreased if ATP already available;1 max[7]

25.glucose converted to pyruvate (two molecules);by glycolysis;pyruvate enters the mitochondria;pyruvate converted to acetyl CoA / ethyl CoA;by oxidative decarboxylation / NADH and CO2 formed;fatty acids / lipids converted to acetyl CoA;acetyl groups enter the Krebs cycle (accept acetyl CoA);FAD / NAD+ accepts hydrogen (from respiratory substrates) to form NADH / FADH2;FADH2 / NADH donates electrons / hydrogen to electron transport chain (rejectdonates H+);electrons release energy as they pass along the chain;oxygen final electron acceptor;production of water;builds up proton gradient / protons pumped across inner membrane;protons flow into matrix of mitochondria through ATPase;ATP produced;produces 36 / 38 ATP (per glucose);8 maxAccept any appropriate terminology for NAD and FAD.(Plus up to [2] for quality)[8]

26.(a)a group of individuals that could interbreed;to produce fertile offspring;individuals that share a common gene pool;2 max(b)Any three of the following.animalia / animals;plantae / plants;prokaryotae/monera;protoctista;fungi;1 max(c)genus and species;1Both are needed for [1].[4]

27.B[1]

28.C[1]

29.C[1]

30.C[1]

31.Answers must include both similarities and differences to receive full marks.aerobic requires oxygen and anaerobic does not utilize oxygen;similarities: 3 maxboth can start with glucose;both use glycolysis;both produce ATP/energy (heat);both produce pyruvate;carbon dioxide is produced;(both start with glycolysis) aerobic leads to Krebs' cycle and anaerobicleads to fermentation;differences: 5 maxanaerobic:(fermentation) produces lactic acid in humans;(fermentation) produces ethanol and CO2 in yeast;occurs in cytoplasm of the cell;recycles NADH (NAD+);aerobic cellular respiration:pyruvate transported to mitochondria;further oxidized to CO2 and water (in Krebs' cycle);produce a larger amount of ATP (36-38 ATP) / anaerobic produces less ATP (2);can use other compounds / lipids / amino acids for energy;[8]

32.(a)ATP;CO2;ethanol;lactic acid;heat energy;1

(b)ReactionOxidationReductionElectrons gained or lostloss of electronsgain of electrons;Oxygen or hydrogen gained or lostgain of oxygen / loss of H+ / hydrogenloss of oxygen /gain of H+ / hydrogen;2Award [2] for four correct and [1] for two correct.(c)A matrix: site for Krebs' cycle / link reaction / ATP synthesis;B inner membrane/cristae: site of oxidative phosphorylation / e transport chain / increase surface area / ATP synthesis;C inter membrane : H+ / proton build up;orC outer membrane: determines which substances enter the mitochondrion;3 maxAward [1 max] if only the three labels are given.[6]

33.(a)06:00 / 19:30 to 19:451Accept 6 am / 7:30 pm to 7:45 pm.(b)23 mg CO2 hl (0.1) (units required)1(c)more uptake at 15C than 30C during the hours of daylight;both are high during the hours of daylight / reverse argument;greater uptake at 30C than 15C during the hours of darkness;at only 15C uptake become negative;3 max(d)respiration rate greater than photosynthesis (during the hours of darkness)1[6]

34.B[1]

35.C[1]

36.(a)(i)07:30 / 7.30 am / 7.5 hours (accept answers in range up to 07.45)1(ii)17:00/5.00 pm ( hour)1(b)250 ppm ( 30 ppm) (unit required)1(c)at night / darkness / no light only respiration occurs so CO2 increases;in day / with light both respiration and photosynthesis occur / photosynthesis exceeds respiration in day;CO2 is used by photosynthesis and level decreases;when sun sets, CO2 again increases as only respiration occurs;2 max[5]

37.C[1]

38.(a)Award [1] for any two products.ATP;NADH;pyruvate;1 max(b)polar amino acids are hydrophilic and non-polar amino acidsare hydrophobic;position of polar and non-polar amino acids determineprotein shape / function / location;(in channel proteins) hydrophilic amino acids line thechannels and allow transport of ions/polar substances;non-polar amino acids are in contact/embeddedwithin the lipid membrane;polar amino acids on the surface proteins makethem water soluble;non-polar in the centre of water-soluble proteinsstabilize the structure;3 maxAccept any of the above points if clearly explained using a suitably labelled diagram.[4]

39.(a)between 1.5 and 3.5 hours (or number between these figures)after feeding mealworm RQ values are higher than for millet;no difference in RQ values between 3.5 hours and 6 hours;between 0.5 and 1.5 hours (or number between these figures)millet RQ values much higher than for mealworm;between 2 and 3 hours mealworm RQ values areslightly higher than for millet;2 max(b)millet is not composed entirely of carbohydrates;millet contains more carbohydrates;mealworms contain more lipids / proteins;2 max(c)(i)using carbohydrate (from millet as a respiratory substrate)1 (ii)reverting to other substrates /carbohydrates (from millet) used up1[6]