KCSE Cellular Respiration — practice questions
120 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice KCSE Cellular Respiration in the app →An oxidation reaction strips an electron from an atom in a compound and that electron is added to another compWhat happens to the potential energy of a compound when an electron is removed from it?Why is it useful for a cell to move energy about as high-energy electrons rather than releasing it all at onceThe principal electron carriers of cellular respiration are derivatives of nucleotides and come from which groWhich statement correctly pairs nicotinamide adenine dinucleotide with its oxidation state?How many electrons and protons does the oxidized form of nicotinamide adenine dinucleotide accept when it becoIn a reaction where an organic molecule RH gives its electrons to the oxidized carrier of nicotinamide adenineHow does the second variation of nicotinamide adenine dinucleotide, called NADP, differ in structure from NAD?Which pair of processes relies most heavily on NADP rather than on the carriers used to strip energy from sugaWhy can a living cell not simply store large amounts of free energy inside itself?Adenosine triphosphate is built from a core molecule of adenosine monophosphate. Which three parts make up thaWhy are the phosphate groups arranged in series in adenosine diphosphate and adenosine triphosphate inherentlyWhat is the term for the removal of a phosphate group from a molecule?What two products are formed when adenosine triphosphate is hydrolysed, alongside the release of free energy?In nearly every living thing on earth, where does the energy to regenerate adenosine triphosphate from adenosiDuring an endergonic reaction driven by adenosine triphosphate, what does the transfer of the third phosphate Which method of making adenosine triphosphate takes a phosphate group straight from an intermediate reactant iWhat percentage of the adenosine triphosphate made during glucose catabolism is generated by chemiosmosis?Where does chemiosmosis take place in a prokaryotic cell, which has no mitochondria?Why is the production of adenosine triphosphate by chemiosmosis in mitochondria called oxidative phosphorylatiIn type 2 diabetes, reduced oxidation efficiency of NADH affects which part of cellular respiration?In which part of the cell does glycolysis take place in both prokaryotes and eukaryotes?Glycolysis does not use oxygen. What term describes a process of this kind?Which group of integral proteins assists the facilitated diffusion of glucose into heterotrophic cells?Glycolysis begins with one six-carbon glucose molecule. What does it end with?What is the job of the first half of the glycolysis pathway?Which enzyme catalyses the very first step of glycolysis by phosphorylating glucose?Why can glucose-6-phosphate no longer leave the cell once it has been formed?An isomerase converts glucose-6-phosphate into which molecule during the second step of glycolysis?Which enzyme adds the second phosphate during glycolysis and acts as a rate-limiting enzyme for the pathway?How does a high concentration of adenosine triphosphate together with low adenosine diphosphate affect phosphoWhich enzyme cleaves the six-carbon sugar of glycolysis into two three-carbon isomers?Why does the fifth step of glycolysis convert dihydroxyacetone-phosphate into glyceraldehyde-3-phosphate?How many molecules of adenosine triphosphate has the cell invested by the end of the fifth step of glycolysis?The sixth step of glycolysis adds a second phosphate group to the sugar. What is notable about that phosphate?Which carrier must be regenerated in its oxidized form for the second half of glycolysis to keep running?In an environment without oxygen, which alternative pathway restores the oxidized carrier needed by glycolysisWhich enzyme catalyses the seventh step of glycolysis, in which 1,3-bisphosphoglycerate donates a phosphate toWhat change takes place during the eighth step of glycolysis?Enolase catalyses a dehydration reaction in the ninth step of glycolysis. What is the product?Counting gross output, how many adenosine triphosphate and NADH molecules does glycolysis produce from one gluWhat is the net gain to the cell from glycolysis after the initial investment is repaid?Mature mammalian red blood cells cannot carry out aerobic respiration. What follows from that fact?If pyruvate kinase is not present in sufficient quantity, what happens to glycolysis?In a eukaryotic cell, where are the pyruvate molecules made by glycolysis taken once oxygen is available?Which carrier compound picks up and activates the acetyl group derived from pyruvate?Coenzyme A is made from which vitamin?What is released when a carboxyl group is removed from pyruvate during its conversion to an acetyl group?How many carbons of the original glucose molecule have been released as carbon dioxide by the time both pyruvaDuring the oxidation of the hydroxyethyl group to an acetyl group, where do the removed electrons go?Acetyl coenzyme A delivers its acetyl group to which four-carbon acceptor at the start of the citric acid cyclWho first identified the steps of the citric acid cycle, and in which tissue?Why does the pathway that starts with citrate carry the alternative name TCA cycle?In which compartment does the citric acid cycle take place?Almost every enzyme of the citric acid cycle is soluble. Which single enzyme is the exception, and where does What is the key structural difference between glycolysis and the citric acid cycle?How many steps make up the citric acid cycle?Which statement about the citric acid cycle and oxygen is correct?Why is the first step of the citric acid cycle irreversible?What happens to the rate of the first reaction of the citric acid cycle when adenosine triphosphate levels risCitrate is converted into its isomer isocitrate in step two. How does this happen?The oxidation of isocitrate in step three produces a molecule with how many carbon atoms?Which enzyme of the citric acid cycle is inhibited by feedback from adenosine triphosphate, succinyl coenzyme In step five of the citric acid cycle, what replaces coenzyme A on the succinyl group?Which tissues carry the form of the step five enzyme that produces adenosine triphosphate rather than guanine Guanine triphosphate is energetically equivalent to adenosine triphosphate, but which process uses it in partiStep six of the citric acid cycle transfers two hydrogen atoms to a carrier. Which carrier accepts them, and wHow does the reduced carrier made at step six differ in behaviour from NADH?How is oxaloacetate regenerated at the end of the citric acid cycle?How many carbon dioxide molecules are released on each turn of the citric acid cycle?How many NADH molecules are formed on each single turn of the citric acid cycle?Why is the citric acid cycle described as amphibolic?Which part of glucose metabolism is the only one that uses atmospheric oxygen?What happens to the electrons at the endpoint of the electron transport chain?Where is the electron transport chain located in a eukaryotic cell?Which two components make up complex I of the electron transport chain?What is a prosthetic group?How many hydrogen ions can complex I pump across the inner mitochondrial membrane?The enzyme of complex I is a very large protein. How many amino acid chains does it contain?Which compound connects the first and second complexes of the electron transport chain to the third?Why do the electrons that enter at complex II ultimately yield fewer adenosine triphosphate molecules?The number of adenosine triphosphate molecules obtained is directly proportional to which quantity?Cytochrome proteins carry a prosthetic group of heme. How does this heme differ from the heme in haemoglobin?Between which two oxidation states does the iron ion of a cytochrome fluctuate as it passes electrons?How does the electron-carrying capacity of cytochrome c differ from that of ubiquinone?In complex IV, what happens once the tightly held oxygen molecule is completely reduced?What kind of gradient does the uneven distribution of hydrogen ions across the membrane establish?Which integral membrane protein lets hydrogen ions cross the inner mitochondrial membrane and uses their movemThe enzyme that phosphorylates adenosine diphosphate in the inner membrane is compared to which kind of deviceDinitrophenol makes the inner mitochondrial membrane leaky to protons. Until which year was it used as a weighCyanide is a metabolic poison. Which component of the electron transport chain does it inhibit?Which statement best describes the number of adenosine triphosphate molecules generated from catabolising one Why must electrons from the NADH made in glycolysis be picked up again by a carrier inside the mitochondrion?Roughly what proportion of the energy contained in glucose is extracted by the pathways of glucose catabolism How many large multiprotein complexes and how many small diffusible carriers make up the electron transport chAt how many points along the electron transport chain is free energy used to transport hydrogen ions across thIn aerobic respiration, what serves as the final electron acceptor?What is the fundamental difference between fermentation and anaerobic cellular respiration?Which group of Archaea reduces carbon dioxide to methane in order to oxidize NADH?Sulfate-reducing bacteria and Archaea regenerate their oxidized carrier by reducing sulfate to which product?Which type of fermentation runs routinely in mammalian red blood cells and in oxygen-starved skeletal muscle?What happens to the lactic acid that builds up in a working muscle?Which enzyme catalyses the conversion of pyruvic acid to lactic acid?What inhibits the forward direction of the reaction that turns pyruvic acid into lactic acid?What is the current standing of the old belief that lactic acid build-up causes muscle stiffness and soreness?In alcohol fermentation, what is produced when a carboxyl group leaves pyruvic acid?Which enzyme catalyses the first reaction of alcohol fermentation, and where in the cell does it work?What range of ethanol tolerance is reported for yeast, depending on strain and conditions?What does it mean to say that many prokaryotes are facultatively anaerobic?How does oxygen affect an obligate anaerobe such as Clostridia?Which single form of fermentation does not produce gas?Which step of glycolysis would stall if no fermentation pathway were available in the absence of oxygen?Is the regeneration of the oxidized carrier during fermentation accompanied by the production of adenosine triInto which two pathways do the catabolic routes for carbohydrates, proteins and lipids eventually connect?Why are metabolic pathways described as porous rather than as closed systems?Where is glycogen made and stored in animals?Glycogen is broken down into glucose-1-phosphate. What must happen before that product can enter the glycolytiWhich three dietary monosaccharides are absorbed directly into the bloodstream during digestion?How does the adenosine triphosphate yield from catabolising fructose or galactose compare with that from glucoWhat must be removed from an amino acid before its carbon skeleton can enter the pathways of glucose catabolis