In which process is pyr0,:twpbmt p et(qea9i+ hgc75uvate converted to acetyl CoA?

  Which pair of characteristics are correct descriptions of aerobic and anaerobipip t5igpf 6uc/x wos6a z0;9:c cellular resp6 act9i pouw6xsf; gizpp/0:5 iration?

  In chemiosmosis, what is the name of the enzyme which plays an important + *xsp p/r3ypvrole in the diffusion of protons into the matrix oy+pxp vr/* ps3f the mitochondrion?

  What happens after the oxidative decauc( yjw;nyjcp*e+hxih r : + .bc5q**brboxylation of pyruvate?

  What are the products of the hydrolwqd. xeef1 v.u+jf))l u85rerysis of ATP?

  Which of the following diagrams shows the corre :eng gxlw3;8:a e*b)b8j*/jbdzuy imct structure of ATP?

  Which of the following processe b*zo. 1o3rs/xveg*5dj6kclbs does not require energy from ATP?

  Which of the following requires ATP as an imme; :e:ij p; nr/rqk(/bqu kem6rdiate source of energy?
I.Transmission of a nerve impulse
II.Osmosis
III.Condensation of a polypeptide

  Which substance is present in the brewing of beer bu/ptts3h1fq r0b;f:l8 0kfg gr t not found in bread?

  How many times does phosphorylation happeq sl1)n(os0d sn in glycolysis?

  In respiration which process rt 9l7w7 nmmx(does not involve the conversion of ADP to ATP?

  There are four main stages of respiratio3 nctch 3pt+ 7b1kja1 qf-3vjmn.
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 tarjt. b87)o1h:o 51wo0u.gr yd dgskz cke place in the mitochondria. The electron micrograph shows an image of a mitochondrion from a mouse emb)j.o5g 1 o gdr1hwc:ydu7s0k 8.ozr tbryonic 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 chain.l hd5 0e ds27bwv1j7 wrylue78

What explains the role of oxygen?

Coleus blumei is an attractive houseb7( i.4uvd;c m yahmy6plant 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 involve .pbko5to(rs5 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 stages9wwk .z6vrxwq5n -ivn htb/dn: k9g; 8 in aerobic cellular respiration. Which of the following correctly describes the electron carriers9rz5tigx:bv9w hkdnn k q6vn ;w-w.8/ ?

  Which of the following correctly descri06ne vs) r1qezbes photosynthesis or respiration?

  A mitochondrion is shown in the diagrampavapy; ;yn a 67ak3k8. Which letter indicates the site where protons accumulate prior to the for;7n 6kkaypp3;ava 8ay mation of ATP?

  The graph shows the changes in blood pH levels of an individual before exerc 2mlri52c0a zyise, d r5y20il2a zcmuring exercise and after exercise.


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

Cell respiration is a metabolic process that occurs in living organismsheh.tgu1 851r,;gqof3bouwm.
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 structures or location/y rwo,/xj*f ls labelled. Which is a correct description of how one of these strucolyj,rw x/f* /tures is adapted to its function?

Oxidative phosphorylation, which generates ATP for the cell, is comprised ovn0h.v,sq04zz nc9ep f the electron trane qnsz zn9p.v,v4 h0c0sport chain and 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 (M 59e3ylmydym, SCs) are found in a variety of tissues, such as the bone marrow and adipose tissue. Due to their multipotency, MCSs can differentiate into a number of different types ofly9m5y,m 3 yed 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 liv,y7ulk//wp f b kot)6ging organisms.
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 investigatin6 a o.*nsjpjj8p pha+* 8*dlfag metabolic reactions in the classroom and were given an experiment which demonstrated the effect of temperature on a catabolic rean sajph**o+.f8p*8 jdajp6l action.
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 oxygen inside a jbu) r dwxs zp/m(lsx;/j-/:ichamber containing yeast cells and substrates as measured byjml:r;//dsp(bi -/ sxxuz)wj an oxygen sensor. The experimental investigation compared the rate of 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 tumf yl5t6uovk8;m vburotp w6(1do40c8ours have abnormal patterns of aerobic respiration, showing increased levels of glycolysis and lower levels of oxidative phosphorylation, even in the presence of high oxygen levels. A breast cancer cell line (MDA-MB-231) shows variable lmuwt5 1pc4(8bvor vd6uf oy k;8ot60 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 powerhouse of the cell because td)rk(fznd n3:m9oba bw5t w3(hey produce a high yield of adenosine triphosphate (ATP) through cell respiration. ar ( 3dnb fw wtd)b(59k:3mnozLarge 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 lactate on the sk)e2l.s vu a)5yqaph n2in of athletes during pr .v2n l)ayq2a5ep )shue-training (rest), training, and recovery.

Based on the graph, which is true?

  Which statement(s) are correct in explaining why lipids are used as ap 2kv3*wow1vo long-term energy sokwv1wo2pv * 3tore instead of 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 measure the respiration rrtudkfji nef3:)x 2 3fnv3m*: / pe4kfate of ger3:4ku jn f/x2rvt3ndme*f :ffki3 ep) minating seeds.


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