In which process is pyruvate converted to sy)u:yaf7 nku77 xy5yacetyl CoA?

  Which pair of characteristics l:9 be6f8en6ly biaq 0are correct descriptions of aerobic and anaerobic cellular respiray69flqnble 60eb i: 8ation?

  In chemiosmosis, whayox.d ev*xp*dy 91y0bt is the name of the enzyme which plays an important role in the diffusion of protons into the matrix of the mitoch d*b1y*.9xvpyodyx 0eondrion?

  What happens after the oxidative decarboxylati lnl0-jn(e9u qon of pyruvate?

  What are the products of the hydrbg/pr fm ts)d)cf) dj3t708liolysis of ATP?

  Which of the following diagrams shows the cor-kp:aozv-+ r3nqq8x3m 1 r quarect structure of ATP?

  Which of the following processes does not reqn- 0nngx) njj,hf/c/fuire energy from ATP?

  Which of the following requires ATP as j3+i6hbujx 4i an immediate source of energy?
I.Transmission of a nerve impulse
II.Osmosis
III.Condensation of a polypeptide

  Which substance is present in the brewing of :dpx9bg( 9yrotgy9i ) beer but not found in bread?

  How many times does phosphorylatio3xhu.5/jsp hg se).ywn happen in glycolysis?

  In respiration which process does not involve the conau brai5/ mv*v-;j3o tversion of ADP to ATP?

  There are four main 6v yw04z8 dogf hii;:cstages of respiration.
Identify the correct row in the table below that is true of these four stages.

There are four stages in cellular respiration. Some of these stages take pla 8 zb1vqj9xb2jce in the mitochondria. The e 1xzjb 8b9vjq2lectron micrograph shows an image of a mitochondrion from a mouse embryonic fibroblast (MEF) cell.

1.Label the diagram with the letter A to indicate the location of ATP synthase.
2.ATP is the energy carrier that provides an immediate source of energy to the cell. State one more energy carrier in cellular respiration other than ATP.
3.Outline the roles of oxidation reactions in oxidative phosphorylation.
4.Explain what would happen to the cell if cellular respiration was an uncontrolled release of energy from glucose.

  The diagram shows part of the electron transport cha jym +va2 e.1(p+rxacnin.

What explains the role of oxygen?

Coleus blumei is an attractive rcu*kwm7w0/h bk1:fl houseplant with red leaves.


1.Determine with a reason whether or not this plant is still able to conduct photosynthesis with red leaves.
2.Red leaves absorb and reflect different coloured light than green leaves. Distinguish between red light and green light in the visible spectrum.
3.Outline how limiting factors affect the rate of photosynthesis.
4.Explain how oxygen produced during photosynthesis can be used during respiration.

  Which of the following processes 89;curftk.3yjc qqw: 2 oqyj6involve decarboxylation?
I.Phosphorylation of glucose
II.Oxidation of pyruvate to form acetyl CoA
III. Oxidation of an acetate group to reform the four-carbon oxaloacetate

  The Krebs cycle is one of the stages in aerobic cellular respirat pl0/o. sev;4gk7t tdcion. Which of the following correctl to04k;. c7sv g/tedlpy describes the electron carriers?

  Which of the following9h)huih96(q j gs8wb w correctly describes photosynthesis or respiration?

  A mitochondrion is shown in thepk4 z+xlogaoc5 5 sj, yq(vst6lb/ m:4 diagram. Which letter indicates the site where protons accumulate prior to the forma vkj/y:xbq mtl+o ca,spz56gs 5l4(o4tion of ATP?

  The graph shows the changes in blood pH levels of an individual before ex9w)ibw *4p 4x pci8 phwia2:asercise, during exercise and after exp:ipi4 h8awwc2 is4)9pabx*w ercise.


Which statement may explain the changes in blood pH shown in the graph?

Cell respiration is a metab2 u1wzxx xs;w-f eea7pd/jbv 5 89w0fedyk))oolic process that occurs in living organisms.
The electron micrograph shows a longitudinal section of a budding yeast cell.


1.ATP is a readily available source of energy for a cell. The primary substrate for the production of ATP is glucose. State one more possible substrate other than glucose.
2.Identify the part of the yeast cell labelled A in the image.
3.The ability of yeast to produce carbon dioxide is used in the making of food and beverages. Outline the role of carbon dioxide in the making of bread.
4.Discuss which type of respiration is adapted for high-intensity activities such as weightlifting and sprinting.

  Below is a micrograph of mitochondria with four structuresg7 p4+fw7yvlzb)0 yc1x f+b rg or locations labelled. Which is a correct description of how one of these structures is adapted to its functi07zx r++cybv f4wy ggb7pf1l) on?

Oxidative phosphorylation, which generates ATP f0y2s6+i -yyyg vul, wuor the cell, is comprised of the electron transport chain al062ywy sygy- iuv, u+nd chemiosmosis.
1.Distinguish between the electron transport chain in aerobic cellular respiration and the electron transport chain in photosynthesis.
2.Outline how ATP can be recycled after being used by the cell.
3.Explain how 38 molecules of ATP can be produced from one glucose molecule in a cell.

  Human mesenchymal stem cells (MSCs) are found i/gdhb: a,x, xu tiqb5 0cd1y4vn a variety of tissues, such as the bone marrow and adipose ticx 4u5,ddbhiq/ gtb,1:x0v a yssue. Due to their multipotency, MCSs can differentiate into a number of different types of cell.
Recent studies have suggested that changes in metabolism are vitally important during the process of cell differentiation. In one such study, scientists investigated the changes which occur to the mitochondria in MSCs during the process of differentiation into adipogenic cells, which are cells of the adipose tissue, an important energy storage site in the body.
To begin the investigation, scientists had to stimulate the differentiation of MSCs into adipogenic cells. Differentiation of MSCs was confirmed with the use of both Oil Red O staining and RT-PCR, which demonstrated the relative expression of adiponectin mRNA, which is a key indicator of adipogenic differentiation.


1. 1.Calculate how many times greater the expression of adiponectin is in adipogenic cells after 21 days, compared to 7 days.  
2.Predict the relative expression of adiponectin mRNA after 14 days. `  

In their next experiment, scientists stained mitochondria in undifferentiated MSCs and differentiated adipogenic cells after 7 days, using MitoTracker Green stains, and then using flow cytometry, recorded fluorescence as a measure of mitochondrial mass.

2. 1.Suggest why there is an increase in mitochondrial mass in adipogenic cells after 7 days compared to MSCs.
2.Calculate, as a percentage, the increase in mean fluorescent intensity in adipogenic cells after 7 days compared to MSCs.  %

In their penultimate experiment, scientists measured the TOM20 protein levels of the outer mitochondrial membrane.


3.Compare and contrast the results obtained from the measurement of mitochondrial mass using flow cytometry and protein levels.

In their final experiment, scientists measured the mitochondrial oxygen consumption rate and lactate production in both MSCs and adipogenic cells.

4. 1.Outline the effect of differentiation on the rate of oxygen consumption and lactate production.
2.Suggest a reason for the change in oxygen consumption rate in adipogenic cells from day 1 to 7.
3.Explain, with reference to respiration, the change in lactate production in adipogenic cells.
5.Explain how the results obtained from these experiments on mitochondria can be used to understand metabolic changes during differentiation.
6.Using all the data provided, evaluate the hypothesis that the rate of respiration increases during cell differentiation

DNA and RNA are nucleic acids that are essential to all living orga9rmorvr+m7tt36 c* (x tp3j adnisms.
1.Distinguish between ATP and DNA.
2.Discuss model-making as an approach used in the discovery of the structure of DNA and the importance of this discovery.
3.DNA is a polymer of nucleotides. Describe the structure of DNA.

  Students were investigating metabolic reactions in the classroom and wer2euux/sk8wta13y. n hgt9h 7be given an experiment which demonstrated the effect of temperature on a cayh7us/ bwh12.t8gta exu3n9k tabolic reaction.
A sample of fat was added to a beaker, which contained 150ml of a 1% sodium chloride solution.



The beaker and its contents were then added to a water bath, which was set at 15
o
C. The beaker was given 5 minutes to equalise with the temperature of the water bath. After 5 minutes,5 ml of a 2% lipase solution, at the same temperature as the water bath, was added to the beaker.


5 ml of 2 % sodium hydroxide (NaOH), pH 8.4, was added to a test tube and phenolphthalein, a colourless solution which turns pink in basic environments, was then added. The intensity of the pink colour is proportionate to the strength of the basic solution.
At exactly 20 minutes, a 5ml sample was taken from the beaker incubated in the water bath and added to the test tube.


The contents of the test tube were then immediately transferred into a cuvette and placed in a spectrophotometer set at 420 nm. The percentage transmission of light able to pass through the sample was measured and recorded.


The procedure was then repeated using water baths set at a range of different temperatures. The measurements were recorded in a table and presented in a graph.



1. 1.State the independent variable in this experiment.
2.Identify two factors, not already mentioned, that would need to be controlled in this experiment.
2. 1.Explain how the spectrophotometer is able to measure the breakdown of fat.
2.Explain the effect of increasing the temperature from 15
o
C to 35
o
C on the rate of the catabolic reaction.
3.Predict the percentage transmission for a sample incubated at 20
o
C.  %
4.Evaluate the claim that based on the data, the optimum temperature for lipase activity is 35
o
C.

  The graph shows the amount of oxyetn zfg,0 y2+zgen inside a chamber containing yeast cells and substrates as measured by an oxygen sensor. The experimental investigation compared the rate ofzt,0e+2f gyzn oxygen consumption during aerobic respiration by the yeast cells using three different substrates: sucrose, fructose and glucose.


What can be concluded from the graph?

Cancer studies have shown that many tumours have abnormal patterns of aerobicm z92qv,bwzu, respiration, showing increased levels of glycolysis and lower levels of oxidative phosphorylation, even in the presence of high oxygen levels. A breast caq w2v9u ,z,zmbncer cell line (MDA-MB-231) shows variable protein expression of complex III in the electron transport chain compared to normal breast tissue.



1.State the independent variable in this study.
2.Outline the role of the complexes in the electron transport chain.
3.Suggest one advantage and one disadvantage of breast cancer cells using glycolysis to generate ATP rather than oxidative phosphorylation.
4.Predict, with a reason, what would happen to the levels of oxidative phosphorylation in the non-cancerous cells if they were treated with an inhibitor of glycolysis.
5.Explain why non-cancerous breast cancer cells were used as a control in this study.
6.The researchers concluded that downregulation of complex III in breast cancer cells is a cause of breast cancer. Evaluate this conclusion.
7.Outline one measurement that could be taken to determine the activity of Complex III in this study.

Mitochondria are known as the p w dqe,,jr4(9lwgh+vaowerhouse of the cell because they produce a high yield of adenosine tw,wr ,delvq9a(gj4+hriphosphate (ATP) through cell respiration. Large numbers of mitochondria can be found in muscle cells.
1.Distinguish between anaerobic respiration in muscle and yeast cells.
2.Outline the role of ATP in cells.
3.Explain how the rate of cellular respiration can be measured.

  The graph below shows the changes in the levels of la ))f zebkn:5ao2aug.kctate on the skin of athletes during pre-tr.nk:uegabkz) ao)5f 2aining (rest), training, and recovery.

Based on the graph, which is true?

  Which statement(s) are correct in explaining why lipids are + 09kc. fzrjofused as a long-term energy store instead of fkjo.z0cr9f+ carbohydrates?

I.Lipids contain more energy per gramme than carbohydrates
II.Lipids are insoluble, whereas carbohydrates are not
III.Lipids contain less oxygen than carbohydrates

  A respirometer is a device that can be used to meas4xh+ 3kf+qd5: w kgwrsure the respiration rate of germinating qh4w5sfx3kwkd gr: ++ seeds.


In the experimental set-up shown above, how is the rate of oxygen uptake measured?