Catabolism: Energy Release and Conservation Flashcards
The total of all chemical reactions occurring in a cell is called \_\_\_\_\_\_\_\_. A) anabolism B) catabolism C) metabolism D) None of the choices are correct.
C
Metabolic pathways can be either catabolic or anabolic but not both.
False
________ pathways are those that function both catabolically and anabolically.
Amphibolic
The catabolism of glucose begins with one or more of the glycolytic pathways that yield pyruvate.
True glycolysis
________ ________ is a process that can completely catabolize an organic energy source to CO2 using the glycolytic pathways and TCA cycle with O2 as the terminal electron acceptor for an electron transport chain.
Aerobic respiration
Very few Gram-positive bacteria utilize the Entner-Doudoroff glycolytic pathway.
True almost none
Some aerobic bacteria lack the Entner-Doudoroff and Embden-Meyerhoff pathways and instead use the pentose phosphate pathway for glycolysis.
False
An organism may use glycolysis and the pentose phosphate pathway simultaneously.
True
The net gain of ATP per molecule of glucose metabolized anaerobically via the Embden-Meyerhof pathway in prokaryotes is ________.
2 becuase no oxygen
The net gain of ATP per molecule of glucose metabolized to pyruvate using Entner-Doudoroff pathway is ________.
1
The pentose phosphate pathway produces \_\_\_\_\_\_\_\_. A) CO2 B) NADPH C) glyceraldehyde 3-phosphate D) All of the choices are correct.
D
The synthesis of ATP from ADP and Pi, when coupled with an exergonic chemical reaction is called \_\_\_\_\_\_\_\_ phosphorylation. A) chemiosmotic B) oxidative C) substrate-level D) conformational change
C
) The most common pathway for conversion of glucose to pyruvate is \_\_\_\_\_\_\_\_. A) Entner-Doudoroff B) Pentose phosphate C) Embden-Meyerhoff D) mixed acid fermentation
C make sure not to confuse with A
The TCA cycle generates all of the following from each acetyl-CoA molecule oxidized except \_\_\_\_\_\_\_\_. A) three NADH molecules B) two CO2 molecules C) one FADH2 molecule D) two ATP or GTP molecules
D
The pyruvate dehydrogenase complex oxidizes and cleaves pyruvate to form one CO2 and \_\_\_\_\_\_\_\_. A) lactate B) isocitric acid C) acetyl-CoA D) succinyl-CoA
C
After glycolysis, pyruvate is oxidized to one CO2 and the two-carbon molecule acetyl-CoA by a multienzyme system called the ________ ________ complex.
pyruvate dehydrogenase
TCA cycle enzymes are found in the ________ ________ of eukaryotic cells
mitochondrial matrix
Krebs cycle
In the TCA cycle, two carbons are removed from citric acid in the form of \_\_\_\_\_\_\_\_, thereby regenerating oxaloacetate to complete the cycle A) acetyl-CoA B) ethanol C) carbon dioxide D) methanol
C
In the TCA cycle, two carbons in the form of \_\_\_\_\_\_\_\_ are added to oxaloacetate at the start of the cycle. A) acetyl-CoA B) ethanol C) carbon dioxide D) methanol
A
The major function(s) of the TCA cycle is(are) ________.
A) energy production
B) provision of carbon skeletons for biosynthesis of cell components
C) electron transport
D) energy production and provision of carbon skeletons for biosynthesis of cell components
D
When mitochondria pass electrons donated by NADH through the electron transport chain to molecular oxygen, a theoretical maximum of ________ molecules of ATP can be made per oxygen molecule reduced.
3
The hypothesis that proton motive force drives ATP synthesis is called the ________ hypothesis.
chemiosmotic
The most commonly accepted hypothesis for the production of ATP that results from electron transport system is called the ________ hypothesis.
chemiosmotic
Bacterial electron transport chains may be comprised of fewer components and have lower phosphate to oxygen (P/O) ratios than mitochondrial transport chains.
True
The electron transport systems in eukaryotes and prokaryotes use different electron carriers.
True
In addition to being used in the making of ATP, a proton motive force is used directly to power the rotation of bacterial flagella
True
Differences between mitochondrial and E. coli electron transport chains include which of the following?
A) The E. coli chain contains a different array of cytochromes.
B) The fundamental principles on which they operate are different.
C) Higher P/O values are observed in E. coli.
D) The electron transport chain does not involve membranes in E. coli.
A
Which of the following is NOT true regarding ATP synthases?
A) They require proton motive force to make ATP.
B) They span the inner membrane of mitochondria.
C) The proton flow is outward during ATP synthesis.
D) The subunits of ATP synthase undergo conformational changes during ATP production.
C
The theoretical maximum net gain of ATP per molecule of glucose metabolized aerobically in eukaryotes is \_\_\_\_\_\_\_\_. A) 2 B) 32 C) 38 D) 85
C
Production of ATP using the energy liberated when electrons from reduced chemical bonds are passed through the electron transport system is generally referred to as \_\_\_\_\_\_\_\_. A) chemiosmotic B) respiration C) substrate-level D) conformational change
B
Mitochondrial electron transport takes place ________.
A) on the outer mitochondrial membrane
B) on the inner mitochondrial membrane
C) in the fluid matrix of the mitochondria
D) on the outer mitochondrial membrane and on the inner mitochondrial membrane
B
In higher eukaryotes, most aerobically generated ATP is produced by ________.
A) glycolysis
B) the TCA cycle
C) a membrane-bound proton translocating ATP synthase during oxidative phosphorylation
D) All of the choices are correct.
C
The number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed from NADH or reduced FAD (FADH) to O2 is called the \_\_\_\_\_\_\_\_. A) utilization ratio B) energy yield C) P/O ratio D) phosphorylation coefficient
C
In aerobic conditions, it takes ________ sugar to produce the same amount of ATP when compared to anaerobic conditions.
less
Prokaryotes may use several different terminal oxidases for the electron transport system.
True
Which of the following can be used as electron acceptors during anaerobic respiration? A) Nitrate B) Sulfate C) Carbon dioxide D) All of the choices are correct.
D
Organisms that form lactate, ethanol, and CO2 as end products of glucose metabolism are called ________ fermenters.
heterolactic
Fermentation involves the use of pyruvate and/or other organic molecules as electron acceptors.
True
In the process of fermentation an organic substrate, such as glucose, is reduced and an intermediate of the pathway, such as pyruvate, is oxidized.
False
Oxygen is always required for the regeneration of NAD from NADH.
False
Large external polysaccharides are degraded by bacteria and archaea using ________ ________, which they secrete outside the cell.
hydrolytic enzymes
Disaccharides and polysaccharides can be processed as nutrients after first being cleaved to monosaccharides by either ________ or ________.
hydrolysis; phosphorolysis
Fatty acids are metabolized by the \_\_\_\_\_\_\_\_ pathway. A) alpha-oxidation B) beta-oxidation C) gamma-oxidation D) delta-oxidation
B
During breakdown of fatty acids, carbons are removed \_\_\_\_\_\_\_\_ at a time with each turn of the cycle, and two carbon units are released as \_\_\_\_\_\_\_\_. A) one; carbon dioxide B) one; methane C) two; acetyl-CoA D) two; ethanol
C 2-acetyl CoA
Proteins are catabolized by hydrolytic cleavage to amino acids by the action of enzymes called ________.
proteases
Amino acids are processed first by the removal of the amino group through \_\_\_\_\_\_\_\_. A) deamination B) transamination C) phosphorolytic cleavage D) deamination or transamination
D
________ is a two-step process that depends on the activity of at least two genera to carry out the oxidation of ammonia to nitrate.
Nitrification
Which of the following may be used as sources of energy by chemolithotrophs? A) Hydrogen gas B) Reduced nitrogen compounds C) Reduced sulfur compounds D) All of the choices are correct.
D
How many molecules of ATP are needed to reduce one molecule of carbon dioxide to carbohydrate by oxygenic phototrophs during the dark reactions of photosynthesis? A) 2 B) 3 C) 4 D) 10–12
B—3
How many molecules of NADPH are needed to reduce one molecule of carbon dioxide to carbohydrate by oxygenic phototrophs during the dark reactions of photosynthesis? A) 2 B) 3 C) 4 D) 10–12
A–2
How many quanta of light are needed to reduce one molecule of carbon dioxide to carbohydrate during photosynthesis? A) 2 B) 3 C) 4 D) 10–12
D
