REVISION 1 (44 Marks)
IB Standard and Higher level Biology Dulwich College Shanghai
Topic 3 (SL): Chemistry of Life
Topic 8 (HL): Respiration and Photosynthesis
3.7
3.7.1
3.7.2
3.7.3
3.7.4
8.1
8.1.1
8.1.2
8.1.3
8.1.4
8.1.5
8.1.6
Respiration (SL)
Define cell respiration  cell respiration is the controlled release of energy from
organic compounds in cells to form ATP.
State that, in cell respiration, glucose in the cytoplasm is broken down by glycolysis into
pyruvate, with a small yield of ATP.
Explain that, during anaerobic cell respiration, pyruvate can be converted in the
cytoplasm into lactate, or ethanol and carbon dioxide, with no further yield of ATP.
Explain that, during aerobic cell respiration, pyruvate can be broken down in the
mitochondrion into carbon dioxide and water with a large yield of ATP.
Cell Respiration (HL)
State that oxidation involves the loss of electrons from an element, whereas reduction
involves a gain of electrons from an element, whereas reduction involves a gain of
electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen,
whereas reduction frequently involves losing oxygen or gaining hydrogen.
Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP
formation (in the cytoplasm, one hexose sugar is converted into three-carbon atom
compounds – pyruvate, with a net gain of two ATP and two NADH + H +.
Draw and label a diagram showing the structure of a mitochondrion as seen in electron
micrographs.
Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of
NADH + H+, the electron transport chain and the role of oxygen.
In aerobic respiration (in mitochondria in eukaryotes), each pyruvate is decarboxylated
(CO2 removed). The remaining two-carbon molecule (acetyl group) reacts with reduced
coenzyme A, and, at the same time, one NADH + H+ is formed. This is known as the link
reaction.
In the Krebs cycle, each acetyl group (CH 3CO) formed in the link reaction yields two
CO2. The names of the intermediate compounds in the cycle are not required. Thus it
would be acceptable to note:
C2 + C4 = C6  C5  and so on.
Explain oxidative phosphorylation in terms of chemiosmosis.
Explain the relationship between the structure of the mitochondrion and its function.
Paper 1
Multiple Choice (8 Marks)
1.
Of the following products, which is produced by both anaerobic respiration and
aerobic respiration in humans?
I.
Pyruvate
II.
ATP
III. Lactate
A.
I only
B.
I and II only
C.
I, II and III
D.
II and III only
2.
Which is not a product of the Krebs cycle?
A.
CO2
B.
C.
D.
NADH + H
Pyruvate
ATP
+
3.
How many ATP molecules (net yield) are produced per molecule of glucose as a
direct result of glycolysis?
A.
2
B.
4
C.
10
D.
38
4.
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.
5.
What is the “link reaction” in eukaryotic respiration?
Pyruvate joining with coenzyme A to produce CO2 and NADH + H
B.
C.
Oxidation of NADH to yield electrons and protons
Acetyl coenzyme A combining or joining with a C4 compound to give C6 +
coenzyme A
Passage of acetyl coenzyme A through the mitochondrial membrane
D.
6.
+
A.
How are photosynthesis and aerobic respiration similar?
ATP synthetase enzyme
A.
B.
C.
D.
Key:
= both have or use this
Electron transport chain
NADH + H
= both do not have or use this
+
7.
Which row in the table describes the first stage of cellular respiration?
Substrate
Location
Product
Product
A.
pyruvate
mitochondria
oxygen
water
B.
pyruvate
cytoplasm
carbon dioxide
ATP
C.
glucose
mitochondria
pyruvate
water
D.
glucose
cytoplasm
pyruvate
ATP
8.
The diagram below shows the three stages of glycolysis. Which processes are
indicated by I, II and III?
6-carbon glucose
I
6-carbon glucose phosphate
II
3-carbon
sugar phosphate
3-carbon
sugar phosphate
III
3-carbon
pyruvate
3-carbon
pyruvate
I
II
Phosphorylation
A.
Lysis
B.
Phosphorylation
C.
Oxidation and ATP
formation
Phosphorylation
D.
Phosphorylation
Oxidation and ATP
formation
Lysis
III
Oxidation and ATP
formation
Lysis
Oxidation and ATP
formation
Lysis
Paper 2
Section A
Data Analysis (6 marks)
1.
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 15°C and 30°C over a 24-hour period. The units of carbon dioxide
–1.
absorption are mg CO2 h
The results are shown below. The centre of the graph corresponds to –2 mg CO2 h
1
–
–1
and the outer ring is +2.5 mg CO2 h .
2200
2100 (late evening)
2000
1900
1800 (evening)
2400 (midnight)
2300 2.5
0100
2
1.5
1
0.5
0
Π0.5
Π1
Π1.5
Π2
Key:
30ΌC
15ΌC
0200
0300 (early morning)
0400
0500
0600 (morning)
1700
0700
1600
0800
1500 (early afternoon)
0900 (late morning)
1400
1000
1300
1100
1200 (mid-day)
[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)
06:00 / 19:30 to 19:45
1
Accept 6 am / 7:30 pm to 7:45 pm.
(b)
State the maximum rate of carbon dioxide uptake at 15°C.
–l
2.3 mg CO2 h (±0.1) (units required)
(1)
(c)
Compare the rate of carbon dioxide uptake at each temperature in daylight and
darkness.
(3)
more uptake at 15°C than 30°C during the hours of daylight;
both are high during the hours of daylight / reverse argument;
greater uptake at 30°C than 15°C during the hours of darkness;
at only 15°C uptake become negative;
(d)
Suggest why the carbon dioxide uptake may at times be negative.
respiration rate greater than photosynthesis (during the hours of darkness)
(1)
Paper 2
Section A
Short Structured (17 Marks)
1.
The diagram below shows possible pathways for the breakdown of glucose in various
cells.
Glucose
A
Process Q
(no oxygen present)
B
Process R
(oxygen present)
C+D
D+E
(a)
State the names of processes Q and R.
Q: anaerobic respiration / fermentation;
R: aerobic respiration / Kreb’s (citric acid) cycle;
(2)
(b)
Deduce the names of substances A and D.
A: pyruvate / 3-oxopropanoate;
D: carbon dioxide;
(2)
(c)
State the organelle in which process R takes place.
mitochondrion;
(1)
2.
The electron micrographs below show mitochondria in longitudinal section. The
mitochondrion in A is from a bat pancreas cell and that in B is from a mouse liver
cell.
A.
B.
[Source: Tribe and Whittaker, Chloroplasts and Mitochondria, (1972), 31, pp 28–29]
(a)
Annotate the micrographs to show two similarities in the structure of the
mitochondria.
both have two (outer) membranes;
both have cristae;
both have a matrix (with a grainy appearance) / ribosomes;
(2)
(b)
The mitochondria differ in size. State two other differences that are visible in the
mitochondria.
(2)
shape;
arrangement of cristae;
density of cristae;
amount of matrix granules / any reference to dark dots;
(do not accept ribosomes)
(c)
Predict, with two reasons, which of the mitochondria would have been able to
produce ATP at a greater rate.
A / bat’s;
larger size / volume;
greater surface area of cristae / more cristae;
closeness of mitochondria in B mouse reduces rate;
(3)
3.
(a)
State the net gain of ATP molecules during glycolysis of one glucose molecule.
2
(1)
(b)
State where in the mitochondrion the enzymes of the Krebs cycle are found.
Matrix (fluid)
(1)
(c)
Compare the process of chemiosmosis in both respiration and photosynthesis.
(3)
Award [1] for each row, up to [3 max].
Respiration
Photosynthesis
both make ATP;
both involve electron transport;
protons move against a concentration gradient in both;
both require ATP synthetase;
occurs in mitochondrion
occurs in chloroplasts /
thylakoids;
uses energy from oxidation
uses energy from light;
has NADH for electron
production
has water for electron
production;
Section B
Extended Response (13 Marks)
1.
Explain the process of aerobic respiration including oxidative phosphorylation.
(8)
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 (reject
+
donates 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);
Accept any appropriate terminology for NAD and FAD.
(Plus up to [2] for quality)
8 max
2.
Using a table, compare aerobic and anaerobic respiration in a eukaryotic cell.
Award [1] for each correct row, up to [5 max].
Aerobic respiration
Anaerobic respiration
occurs in mitochondria
occurs in cytoplasm;
requires O2
occurs without O2;
both produce pyruvate from glucose (glycolysis);
uses fatty acids / lipids / amino
acids
doesn’t use fatty acids;
(Krebs cycle) produces CO2 and
(fermentation) produces ethanol /
CO2
H2 O
(Krebs cycle) produces CO2 and
H2 O
(in yeast);
(fermentation) produces lactate in
animals (humans);
NADH produced in both;
large amount of ATP (36 per
glucose
molecule) produced
small amount of ATP (2 per glucose
molecule) produced;
(5)