Search results for "Aerobic Respiration"

Biology

CAIE2024

During aerobic respiration, cells respire substrates such as glucose to produce ATP. Some events that occur during aerobic respiration are: • The respiratory substrate breaks down into smaller and smaller molecules. These series of reactions are described as catabolism. • Coenzymes take part in various reactions. In some reactions, coenzymes are reduced or oxidised. • Carbon dioxide is released. (a) Aerobic respiration occurs in four successive stages: glycolysis (G), link reaction (LR), Krebs cycle (KC) and oxidative phosphorylation (OP). Complete Table 3.1 to show which events occur in each stage of aerobic respiration. Use a tick (✓) to show that the event does occur or a cross (✗) to show that the event does not occur. Table 3.1 stage event G LR KC OP catabolism coenzyme is reduced or oxidised a coenzyme forms a covalent bond with a respiratory intermediate carbon dioxide is released [4] (cid:300)(cid:209)(cid:266)(cid:190)(cid:288)(cid:180)(cid:237)(cid:200)(cid:245)(cid:207)(cid:298)(cid:197)(cid:266)(cid:222)(cid:252)(cid:181)(cid:254)(cid:215) © UCLES 2024 (cid:300)(cid:298)(cid:183)(cid:242)(cid:209)(cid:294)(cid:255)(cid:283)(cid:223)(cid:260)(cid:266)(cid:211)(cid:206)(cid:218)(cid:253)(cid:267)(cid:240)(cid:258) 9700/41/O/N/24 (cid:293)(cid:229)(cid:245)(cid:277)(cid:181)(cid:181)(cid:197)(cid:181)(cid:245)(cid:261)(cid:293)(cid:197)(cid:261)(cid:277)(cid:293)(cid:213)(cid:277)(cid:213) NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD PMT * 0000800000007 *

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Biology

CAIE2024

During aerobic respiration, cells respire substrates such as glucose to produce ATP. Some events that occur during aerobic respiration are: • The respiratory substrate breaks down into smaller and smaller molecules. These series of reactions are described as catabolism. • Coenzymes take part in various reactions. In some reactions, coenzymes are reduced or oxidised. • Carbon dioxide is released. (a) Aerobic respiration occurs in four successive stages: glycolysis (G), link reaction (LR), Krebs cycle (KC) and oxidative phosphorylation (OP). Complete Table 3.1 to show which events occur in each stage of aerobic respiration. Use a tick (✓) to show that the event does occur or a cross (✗) to show that the event does not occur. Table 3.1 stage event G LR KC OP catabolism coenzyme is reduced or oxidised a coenzyme forms a covalent bond with a respiratory intermediate carbon dioxide is released [4] (cid:300)(cid:209)(cid:266)(cid:190)(cid:288)(cid:180)(cid:237)(cid:200)(cid:245)(cid:207)(cid:298)(cid:197)(cid:266)(cid:222)(cid:250)(cid:182)(cid:254)(cid:215) © UCLES 2024 (cid:300)(cid:228)(cid:199)(cid:252)(cid:209)(cid:299)(cid:288)(cid:295)(cid:223)(cid:260)(cid:245)(cid:230)(cid:194)(cid:295)(cid:256)(cid:195)(cid:269)(cid:258) 9700/43/O/N/24 (cid:293)(cid:181)(cid:277)(cid:213)(cid:181)(cid:213)(cid:261)(cid:181)(cid:277)(cid:293)(cid:213)(cid:197)(cid:261)(cid:277)(cid:229)(cid:181)(cid:245)(cid:213) NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD PMT * 0000800000007 *

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Biology

CAIE2023

[4] [Total: 8]  UCLES 2007 9700/4/SP07 final [Turn over PPMMTT

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Biology

CAIE2023

Fig. 2.1 shows the main stages of the Calvin cycle. (a) State precisely where the Calvin cycle occurs in plant cells. [1] (b) Describe how carbon dioxide is fixed in the Calvin cycle. [2] (c) Explain how the products of photophosphorylation are used in the Calvin cycle. [3] (d) Explain what initially happens to the concentration of RuBP and GP if the supply of carbon dioxide is reduced. RuBP GP [2] [Total: 8]  UCLES 2007 9700/4/SP07 final PPMMTT

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Biology

CAIE2023

cross pollination

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Biology

CAIE2023

(a) State what is meant by the term respiratory quotient (RQ). [1] (b) (i) Complete the following equation for the aerobic respiration of the respiratory substrate A. C H O + 26O + [2]

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Biology

CAIE2023

The potato plant, Solanum tuberosum, is an important food crop. Crop yield is reduced if the leaves of the plant are eaten by the larvae (immature stages) of the Colorado beetle, Leptinotarsa decemlineata. Crop scientists used recombinant DNA technology to create two genetically modified (GM) varieties of potato plant. These plants produce proteins that are poisonous to insects. • GM potato variety A contains two new genes, SN and Bt. • GM potato variety B contains two new genes, SN and OCII. The new varieties were tested by having a constant number of Colorado beetle larvae introduced to the plants at time 0 hours. The number of larvae that were alive after 24, 48 and 72 hours was recorded. The percentage of the larvae that had died in each time interval was calculated. This was repeated for potato plants that had not been genetically modified (non-GM). Table 4.1 shows the percentage of Colorado beetle larvae that had died on the GM potato plant varieties and on non-GM potato plants. Table 4.1 percentage of Colorado beetle larvae that had died type of potato plant

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Biology

CAIE2023

8 3 glucose C H O 6.0

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Biology

CAIE2023

6 5 oleic acid C H O 25.5

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Biology

CAIE2023

hours You must answer on the question paper. No additional materials are needed. INSTRUCTIONS ● Answer all questions. ● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs. ● Write your name, centre number and candidate number in the boxes at the top of the page. ● Write your answer to each question in the space provided. ● Do not use an erasable pen or correction fluid. ● Do not write on any bar codes. ● You may use a calculator. ● You should show all your working and use appropriate units. INFORMATION ● The total mark for this paper is 100. ● The number of marks for each question or part question is shown in brackets [ ]. This document has 24 pages. Any blank pages are indicated. [Turn over *5046300420* PMT DC (ST/JG) 323130/3 © UCLES 2023 PMT

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Biology

CAIE2023

2

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Biology

CAIE2023

(a) Some organisms carry out respiration in anaerobic conditions when oxygen is not available or when there is a low concentration of oxygen. In yeast and some plants, this is called ethanol fermentation. In mammals, it is called lactate fermentation. Fig. 1.1 outlines ethanol fermentation and lactate fermentation. glucose pyruvate ethanol lactate fermentation fermentation A B C D B C ethanol lactate Fig. 1.1 Identify substances A–D. A ............................................................................................................................................... B ............................................................................................................................................... C ............................................................................................................................................... D ............................................................................................................................................... [3] © UCLES 2023 9700/42/O/N/23 PMT

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Biology

CAIE2023

Yeasts are unicellular organisms from the kingdom Fungi. Saccharomyces cerevisiae is one species of yeast that can carry out either asexual reproduction by mitosis or sexual reproduction by meiosis. Budding in S. cerevisiae is a process where a small daughter cell forms as a bud on the parent cell. The bud contains a copy of the parent cell nucleus and it eventually separates from the parent cell to form a new cell. S. cerevisiae can exist in two forms: haploid cells or diploid cells. • Haploid cells can be one of two different mating types: a and α. • Haploid cells can only mate with other haploid cells of the opposite mating type. Fig. 2.1 shows the life cycle of S. cerevisiae with its asexual and sexual reproductive stages. Key: a mating type a a α α a budding budding α mating type α α a

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Biology

CAIE2023

1 a α α a mating a α formation of 2 zygote a α aα budding aα

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Biology

CAIE2023

3.841 6.635 10.828

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Biology

CAIE2023

5.991 9.210 13.816

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Biology

CAIE2023

When only neurone X is stimulated, an action potential will occur in the postsynaptic neurone.

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Biology

CAIE2023

When only neurone Y is stimulated, an action potential will occur in the postsynaptic neurone.

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Biology

CAIE2023

The potato plant, Solanum tuberosum, is an important food crop. Crop yield is reduced if the leaves of the plant are eaten by the larvae (immature stages) of the Colorado beetle, Leptinotarsa decemlineata. Crop scientists used recombinant DNA technology to create two genetically modified (GM) varieties of potato plant. These plants produce proteins that are poisonous to insects. • GM potato variety A contains two new genes, SN and Bt. • GM potato variety B contains two new genes, SN and OCII. The new varieties were tested by having a constant number of Colorado beetle larvae introduced to the plants at time 0 hours. The number of larvae that were alive after 24, 48 and 72 hours was recorded. The percentage of the larvae that had died in each time interval was calculated. This was repeated for potato plants that had not been genetically modified (non-GM). Table 4.1 shows the percentage of Colorado beetle larvae that had died on the GM potato plant varieties and on non-GM potato plants. Table 4.1 percentage of Colorado beetle larvae that had died type of potato plant

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Biology

CAIE2023

8 3 glucose C H O 6.0

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Biology

CAIE2023

6 5 oleic acid C H O 25.5

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Biology

CAIE2023

For Examiner's Use

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Biology

CAIE2023

[2] [Total: 8]  UCLES 2007 9700/4/SP07 final [Turn over PPMMTT

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Biology

CAIE2023

0.20 0.10

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Biology

CAIE2022

( a) During a sporting event, an athlete carries out aerobic respiration. Structures and compounds involved in aerobic respiration are listed, 1 to 1 0.

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Biology

CAIE2022

(a) The results of investigations carried out on mitochondria show how the structure of a mitochondrion is related to its role in aerobic respiration. • Intact mitochondria (not damaged) were removed from cells. • A technique was used to remove the outer mitochondrial membrane, leaving the inner membrane intact. • The inner mitochondrial membrane was separated from the contents of the matrix so that both could be analysed. (i) The removal of the outer membranes of mitochondria involves placing the organelles in pure water. This results in the rupture (bursting) of the outer membrane. The inner mitochondrial membrane does not rupture and remains intact. Suggest and explain why the inner membrane of a mitochondrion remains intact when the organelle is placed in pure water. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) Name three molecules, other than coenzymes, that are found in the mitochondrial matrix and explain their role in aerobic respiration. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [3] (iii) The inner membrane contains a very high proportion of the molecule cardiolipin. Cardiolipin makes the membrane impermeable to some ions. Suggest why the inner membrane contains a very high proportion of cardiolipin. ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [1] © UCLES 2022 9700/43/O/N/22 [Turn over PMT

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