cell respiration multiple-choice qna
Process A represents *glucose --> process A; 2 ATP in, 4 ATP out* A) glycolysis B) the Krebs cycle C) the electron transport chain D) alcohol fermentation E) lactic acid fermentation
A) glycolysis glycolysis is the first step toward the complete breakdown of glucose and the production of ATP. the next step is the conversion of pyruvic acid to Acetyl-CoA, which enters the Krebs cycle. next in line is the electron transport chain and the creation of the proton gradient that produces the most ATP. alcohol and lactic acid fermentation are not part of aerobic respiration and produce no ATP.
the breakdown of glucose into pyruvic acid occurs during the process of A) glycolysis B) lactic acid fermentation C) the Krebs cycle D) the electron transport chain E) alcohol fermentation
A) glycolysis the breakdown of glucose is the first step in cell respiration. it occurs anaerobically and produces 4 ATP molecules. lactic acid and alcohol fermentation are also anaerobic but use pyruvic acid produced from glycolysis to produce either lactic acid or alcohol and carbon dioxide, respectively. the Krebs cycle and the electron transport chain occur in the presence of oxygen during aerobic respiration.
which of the following is correct about these processes? A) process A requires energy B) process B requires energy C) process C requires energy D) process A depends on a gradient E) process B releases oxygen
A) process A requires energy process A represents glycolysis. it is the only process that requires energy. it requires the input of 2 ATP and releases 4 ATP, for a net gain of 2 ATP. process C, oxidative phosphorylation, establishes a proton gradient. process B is the critic acid cycle.
the role of oxygen in aerobic respiration is A) to transport CO2 B) as the final proton and electron acceptor in the electron transport chain C) to transport electrons in glycolysis D) to provide electrons for the electron transport chain E) most important in the Krebs cycle
B) as the final proton and electron acceptor in the electron transport chain oxygen combines with protons (H+) that have passed through the ATP synthase channels during chemiosmosis after the electron transport chain. it also exerts a strong pull on electrons passing through the electron transport chain. oxygen ions + protons + electrons --> water water is a waste product of cell respiration. that is its only role in cell respiration. oxygen is not a part of glycolysis or the Krebs cycle.
the electron transport chain is located in the A) cytoplasm B) cristae of the mitochondria C) outer compartment of the mitochondria D) inner matrix E) Golgi body
B) cristae of the mitochondria the electron transport chain is a collection of molecules embedded in the cristae membrane of mitochondria. there are thousands of copies of the ETC in every mitochondrion, which greatly enhances the amount of ATP produced.
the loss of electrons is known as A) reduction B) oxidation C) redox D) electron transport chain E) lysis
B) oxidation oxidation is the loss of electrons; reduction is the gain of electrons. redox refers to a reaction where electrons are both gained and lost. the electron transport chain is a set of redox reactions where electrons are lost and gained by molecules like cytochromes. lysis is a process of breaking apart. EX: a cell is lysed if it is placed into a hypertonic solution.
each NADH molecule carrying protons to the electron transport chain can produce as much as ___ molecules of ATP A) 1 B) 2 C) 3 D) 20 E) an unlimited number of
C) 3 NADH delivers electrons to a higher energy level in the ETC than does FADH2. theoretically, each NADH produces 3 ATP molecules, while each FADH2 produces 2 ATP molecules from oxidative phosphorylation and the electron transport chain.
which of the following is a waste product of aerobic cell respiration? I. water II. carbon dioxide III. ATP A) I only B) II only C) I and II only D) III only E) I, II, III
C) I and II only water and carbon dioxide are waste products. water is formed as oxygen combines with protons flowing through the ATP synthase channels during chemiosmosis of aerobic respiration only after the electron transport chain. carbon dioxide is released from the Krebs cycle. ATP is a product of cellular respiration, not a waste product.
which of the following probably evolved first? A) the Krebs cycle B) chemiosmosis C) glycolysis D) the electron transport chain E) the citric acid cycle
C) glycolysis glycolysis occurs during the anaerobic phase of respiration and evolved on ancient Earth. it was possibly the way the first cells produced energy. the Krebs cycle and the electron transport chain evolved after free oxygen appeared on ancient Earth. together they make up the aerobic phase of cell respiration. chemiosmosis is the process of energy production during the electron transport chain. the citric acid cycle is another name for the Krebs cycle.
which is true about process C? A) it requires water B) it is universal. it is the way all organisms produce energy C) it involves the membrane structure ATP synthase D) it only occurs in animals, not plants E) it results in the by-product pyruvic acid
C) it involves the membrane structure ATP synthase process C represents the oxidative phosphorylation. it uses energy from the flow of electrons through the cristae membrane to pump protons across the membrane and create a proton gradient. this gradient will power the phosphorylation of ADP to ATP. this process is carried out by all aerobic organisms, including plants. pyruvic acid is a product of glycolysis and is required for the Krebs cycle. process C is not universal. it is only carried out by aerobic organisms.
Process C represents *glucose --> process A --> process B --> process C; NADH and FADH2 in, H2O out* A) glycolysis B) the Krebs cycle C) oxidative phosphorylation D) alcohol fermentation E) lactic acid fermentation
C) oxidative phosphorylation process C represents the electron transport chain. glycolysis is the first step toward the complete breakdown of glucose and the production of ATP. the next step is the conversion of pyruvic acid to Acetyl-CoA, which enters the Krebs cycle. next in line is the electron transport chain and the creation of the proton gradient that produces the most ATP. alcohol and lactic acid fermentation are not part of aerobic respiration and produce no ATP.
glycolysis A) produces water B) requires oxygen C) involves an electron transport chain D) is the breakdown of glucose to produce pyruvic acid E) produces carbon dioxide
D) is the breakdown of glucose to produce pyruvic acid glycolysis: glyco means sweet (sugar) , lyse means to break apart, and sis means process. glycolysis means the process by which sugar is broken down. pyruvic acid or pyruvate is a 3-carbon molecule and is essentially half a glucose molecule.
all of the following are correct about ATP synthase EXCEPT A) it is a molecule located within the cristae membrane B) it spins like a turbine C) it binds a phosphate to a molecule of ADP D) it is an important component of glycolysis E) its function depends on a proton gradient
D) it is an important component of glycolysis ATP synthase is an important component of aerobic respiration. glycolysis is part of anaerobic respiration.
during strenuous exercise, skeletal muscles use up ___ and produce large amounts of ___, which causes pain and fatigue in the muscle A) pyruvic acid--carbon dioxide B) carbon dioxide--pyruvic acid C) pyruvic acid--lactic acid D) oxygen--lactic acid E) glycogen--carbon dioxide
D) oxygen--lactic acid lactic acid fermentation occurs during strenuous exercise when the body cannot keep up with the increased demand for oxygen by skeletal muscles. pyruvic acid converts to lactic acid that builds up in the muscle, causing fatigue and burning.
which of the following is correct about aerobic cell respiration? A) it is a reductive process B) all plants carry out respiration only during the day C) it consists of glycolysis and fermentation D) protons are pumped across the cristae membrane to the outer compartment E) most ATP is produced during cell respiration as a result of the citric acid cycle
D) protons are pumped across the cristae membrane to the outer compartment cellular respiration is an oxidative reaction. all organisms carry out cell respiration ALL the time. don't confuse respiration with photosynthesis. aerobic respiration consists of glycolysis, the citric acid cycle, and chemiosmosis. anaerobic respiration consists of fermentation. the most ATP produced during cellular respiration is released from chemiosmosis and oxidative phosphorylation.
Process A occurs in *glucose --> process A; 2 ATP in, 4 ATP out* A) mitochondria B) chloroplasts C) the nucleus D) the cytoplasm E) different organelles in different cells
D) the cytoplasm process A represents glycolysis. glycolysis takes place in the cytoplasm of all cells. process B represents the Krebs cycle. process C represents the electron transport chain.
which of the following is the most important thing that occurs during cell respiration? A) CO2 is produced during the Krebs cycle B) protons and electrons combine with oxygen to form water C) oxygen is released D) a proton gradient is created E) ATP is produced
E) ATP is produced although A B and D are all correct about cell respiration, the purpose of the process is to produce energy in the form of ATP. C is incorrect. oxygen is used during cell respiration. it is released during photosynthesis, not during respiration.
the immediate result of the electron transport chain is A) water is produced B) ATP is produced C) lactic acid is produced D) glucose is broken down into 2 pyruvic acid molecules E) a proton gradient is created
E) a proton gradient is created the electron transport chain (ETC) pumps protons across the cristae membrane of mitochondria in order to create a proton gradient. this gradient will power the production of ATP during the process known as chemiosmosis. water is produced after protons flow through ATP synthase channels. lactic acid is produced as a consequence of fermentation. glucose is broken down into 2 pyruvic acid molecules during glycolysis.
choose the pair that is correctly matched A) Krebs cycle--cytoplasm B) electron transport chain--outer compartment of mitochondria C) glycolysis--cristae membrane D) glycolysis-mitochondria E) electron transport chain--cristae membrane
E) electron transport chain--cristae membrane glycolysis occurs in the cytoplasm. the Krebs cycle occurs in the inner matrix of the mitochondria. the electron transport chain occurs in the cristae membrane.
which is true about process B? *glucose --> process A --? process B; NADH, FADH2 to process 3, CO2 out* A) it produces the most energy of all the processes B) it produces energy by chemiosmosis C) its production of energy is explained by the laws of diffusion D) the raw material is pyruvic acid E) it releases carbon dioxide
E) it releases carbon dioxide process B is the citric acid cycle. carbon dioxide is a by-product of the Krebs cycle. pyruvic acid, the product of glycolysis, does not enter the Krebs cycle directly. it first must combine with coenzyme A to produce Acetyl-CoA, which does enter the Krebs cycle. the Krebs cycle produces only a small amount of ATP. C makes no sense
