Start learning →

KCSE Cellular Respiration — practice questions — page 2

Explore 86 free Cellular Respiration questions in KCSE Biology. Open each question or exercise to read its content, reference answers and available explanation.

Practise Cellular Respiration with Quill →

Cellular Respiration questions and exercises with answers

Showing questions 31–60 of 86.

Why does the pathway that starts with citrate carry the alternative name TCA cycle?Read the answer and worked solution →In which compartment does the citric acid cycle take place?Read the answer and worked solution →How many steps make up the citric acid cycle?Read the answer and worked solution →Which statement about the citric acid cycle and oxygen is correct?Read the answer and worked solution →Why is the first step of the citric acid cycle irreversible?Read the answer and worked solution →What happens to the rate of the first reaction of the citric acid cycle when adenosine triphosphate levels rise?Read the answer and worked solution →Citrate is converted into its isomer isocitrate in step two. How does this happen?Read the answer and worked solution →The oxidation of isocitrate in step three produces a molecule with how many carbon atoms?Read the answer and worked solution →In step five of the citric acid cycle, what replaces coenzyme A on the succinyl group?Read the answer and worked solution →Guanine triphosphate is energetically equivalent to adenosine triphosphate, but which process uses it in particular?Read the answer and worked solution →How is oxaloacetate regenerated at the end of the citric acid cycle?Read the answer and worked solution →How many carbon dioxide molecules are released on each turn of the citric acid cycle?Read the answer and worked solution →How many NADH molecules are formed on each single turn of the citric acid cycle?Read the answer and worked solution →Why is the citric acid cycle described as amphibolic?Read the answer and worked solution →Which part of glucose metabolism is the only one that uses atmospheric oxygen?Read the answer and worked solution →Which two components make up complex I of the electron transport chain?Read the answer and worked solution →What is a prosthetic group?Read the answer and worked solution →How many hydrogen ions can complex I pump across the inner mitochondrial membrane?Read the answer and worked solution →The enzyme of complex I is a very large protein. How many amino acid chains does it contain?Read the answer and worked solution →Which compound connects the first and second complexes of the electron transport chain to the third?Read the answer and worked solution →What kind of gradient does the uneven distribution of hydrogen ions across the membrane establish?Read the answer and worked solution →Dinitrophenol makes the inner mitochondrial membrane leaky to protons. Until which year was it used as a weight-loss drug?Read the answer and worked solution →Cyanide is a metabolic poison. Which component of the electron transport chain does it inhibit?Read the answer and worked solution →Roughly what proportion of the energy contained in glucose is extracted by the pathways of glucose catabolism in living systems?Read the answer and worked solution →At how many points along the electron transport chain is free energy used to transport hydrogen ions across the membrane?Read the answer and worked solution →In aerobic respiration, what serves as the final electron acceptor?Read the answer and worked solution →What is the fundamental difference between fermentation and anaerobic cellular respiration?Read the answer and worked solution →Which group of Archaea reduces carbon dioxide to methane in order to oxidize NADH?Read the answer and worked solution →Sulfate-reducing bacteria and Archaea regenerate their oxidized carrier by reducing sulfate to which product?Read the answer and worked solution →Which type of fermentation runs routinely in mammalian red blood cells and in oxygen-starved skeletal muscle?Read the answer and worked solution →

Worked practice questions

Why does the pathway that starts with citrate carry the alternative name TCA cycle?

  1. Because it turns three times per glucose
  2. Because citrate is a tricarboxylic acid
  3. Because it needs three carrier molecules
  4. Because three carbon atoms leave each turn
Show answer and solution

Correct answer: B. Because citrate is a tricarboxylic acid

1. The same pathway is called by three different names for three different reasons. 2. It is the citric acid cycle after citrate, the first intermediate formed. 3. It is the TCA cycle because citric acid and isocitrate are tricarboxylic acids. 4. Tricarboxylic acid is shortened to TCA, so the initials come from chemistry rather than counting. 5. Two carbon dioxide molecules leave on each turn, not three, so the carbon-counting option is wrong on its numbers. 6. The number of turns per glucose is a separate matter and plays no part in the naming. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.3 Oxidation of Pyruvate and the Citric Acid Cycle_

Open this question →

In which compartment does the citric acid cycle take place?

  1. In the matrix of mitochondria
  2. In the intermembrane space
  3. In the outer mitochondrial membrane
  4. In the cytoplasm outside
Show answer and solution

Correct answer: A. In the matrix of mitochondria

1. Glycolysis runs in the cytoplasm, but the next stages move inside the mitochondrion. 2. The conversion of pyruvate to acetyl coenzyme A takes place in the matrix of mitochondria. 3. The citric acid cycle takes place in the same compartment, the matrix. 4. The intermembrane space is where protons collect later, so it hosts no cycle enzymes. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.3 Oxidation of Pyruvate and the Citric Acid Cycle_

Open this question →

How many steps make up the citric acid cycle?

  1. Four steps
  2. Six steps
  3. Eight steps
  4. Ten steps
Show answer and solution

Correct answer: C. Eight steps

1. The citric acid cycle is described as having eight steps. 2. Those eight steps are a series of redox, dehydration, hydration and decarboxylation reactions. 3. They produce two carbon dioxide molecules, one high-energy nucleotide and reduced electron carriers. 4. Ten is the count for glycolysis, which is the usual mix-up. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.3 Oxidation of Pyruvate and the Citric Acid Cycle_

Open this question →

How to practise

  1. Choose a Cellular Respiration question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

More Biology topics

Photosynthesis