Ch. 5

Which of the following would you predict to be a feedback inhibitor of the glycolytic enzyme phosphofructokinase? fructose ADP FAD NAD+ ATP

ATP

The chemical reactions involved in synthesizing proteins and cell wall peptidoglycan are examples of __________ reactions. catabolic photosynthetic anabolic autotrophic

anabolic

_____ involves an inhibitor that fills the active site of an enzyme and competes with the normal substrate for the active site. (Two words)

competitive inhibition

Biochemical tests for the identification of bacteria involve testing fermentation products or amino acid catabolism.

t

The synthesis of sugars by using carbon atoms from CO2 gas is called carbon fixation.

t

Fermentation differs from anaerobic respiration in that fermentation does NOT __________. a) oxidize NADH b) require molecular oxygen c) oxidize glucose d) use an electron transport chain

use an electron transport chain

Which of the following are products of noncyclic photophosphorylation reactions in oxygenic organisms? a) O2 and NADPH b) glucose and O2 c) ATP and NADPH d) O2, ATP, and NADPH

O2, ATP, and NADPH

Which of the following statements is accurate concerning glucose metabolism? Glucose is split in glycolysis and produces large amounts of ATP. Fermentation produces large amounts of ATP. Pyruvic acid, the product of glycolysis, is the starting block for both the Krebs cycle and fermentation. The electron transport chain is the final step for both fermentation and aerobic respiration.

Pyruvic acid, the product of glycolysis, is the starting block for both the Krebs cycle and fermentation

During glycolysis, electrons from the oxidation of glucose are transferred to __________. NADH FAD ADP NAD+ FADH2

NAD+

In an enzymatic reaction involving oxidation of a substrate, which of the following would be required? H2O NAD+ ATP O2 FADH2

NAD+

In fermentation, the electrons from _____ are passed to pyruvic acid to form reduced organic molecules.

NADH

Which of the following molecules carry electrons during various stages of glucose catabolism? pyruvic acid acetyl CoA NADH and FADH2 glucose

NADH and FADH2

Which of the following mechanisms does NOT generate ATP using an electron transport chain? a) anaerobic respiration b) aerobic respiration c) photophosphorylation d) substrate-level phosphorylation

substrate-level phosphorylation

During the light-independent reactions of photosynthesis, organisms __________. a) produce molecular oxygen b) synthesize sugars c) use molecular oxygen to produce ATP d) ferment glucose

synthesize sugars

Enzymes work most effectively at their optimal temperature and pH.

t

Glycolysis produces ATP through substrate-level phosphorylation.

t

Metabolic pathways that function in both anabolism and catabolism are called amphibolic pathways.

t

NADPH produced in noncyclic photosynthesis is used to provide electrons for the fixation of CO2 in the Calvin-Benson cycle.

t

The complete oxidation (catabolism) of glucose typically involves three stages. The greatest number of ATPs is produced in which stage? Krebs cycle the electron transport chain photosynthesis glycolysis

the electron transport chain

Which of the following statements is correct about enzymes? a) Enzymes raise the activation energy of the reaction. b) Enzymes have active sites that interact with a variety of different molecules. c) Enzymes are used up in the reactions they catalyze. d) Each enzyme has a characteristic three-dimensional shape.

Each enzyme has a characteristic three-dimensional shape

All of the following steps are involved in the aerobic electron transport chain. Which step happens last? NADH is oxidized. Protons move to the outside of the membrane. NAD+ is formed. Electrons are transferred to O2. Electrons flow between membrane-bound electron carriers.

Electrons are transferred to O2

Which group of organisms has members representing each of the following nutritional classifications: chemoheterotrophs, chemoautotrophs, photoheterotrophs, and photoautotrophs? protists animals plants bacteria

bacteria

Enzymes are important in living organisms because they __________. a) bind irreversibly to substrates and remove them from the cellular pool b) increase environmental temperatures to increase rates of reactions c) interact with and destroy unwanted cellular substrates d) bring together reactants or properly orient a molecule for a reaction e) catalyze the covalent bonding of NAD+ molecules to substrates

bring together reactants or properly orient a molecule for a reaction

Like glucose, amino acids are catabolized for energy, but these must be converted to a form in which they can enter the Krebs cycle for oxidation. All of the following reactions occur in the catabolism of amino acids EXCEPT __________. a) carbon fixation b) decarboxylation c) dehydrogenation d) deamination

carbon fixation

A Thiobacillus bacterium uses the Calvin-Benson cycle to reduce CO2 and the oxidation of sulfide ions for energy. This organism is a __________. a) photochemotroph b) photoheterotroph c) photoautotroph d) chemoheterotroph e) chemoautotroph

chemoautotroph

All of the following are required for the generation of ATP by chemiosmosis EXCEPT __________. a) passage of electrons through electron carrier chains b) active transport of protons across a phospholipid membrane c) use of proton flow by ATP synthase d) conversion of pyruvic acid to lactic acid e) formation of a proton motive force

conversion of pyruvic acid to lactic acid

You inoculate a bacterial culture into a tube containing glucose and peptides. The pH indicator shows that the pH decreased after 24 hours and then increased at 48 hours. What has caused the increase in pH? a) compounds in the Krebs cycle b) fermentation of glucose c) oxidation of glucose d) deamination

deamination

Biological oxidations are also called _____ reactions.

dehydrogenation

One of the sites of allosteric regulation of the Krebs cycle is the conversion of pyruvic acid to acetyl CoA. Which of the following conditions would you expect to inhibit the conversion of pyruvic acid to acetyl CoA? a) high ATP and low NADH b) high ATP and high NADH c) high ADP and low NADH d) low ATP and high NADH e) low ATP and low NADH

high ATP and high NADH

NADH molecules formed during glycolysis and in the Krebs cycle are __________. oxidized when electrons are passed to the electron transport chain transported out of the cell during oxidative phosphorylation stored in the mitochondria oxidized when electrons are passed to NADP+ oxidized when electrons are needed in anabolic pathways

oxidized when electrons are passed to the electron transport chain

In noncyclic photophosphorylation, _____ is/are produced as water is oxidized.

oxygen

Which of the following molecules traps energy released during oxidation-reduction reactions? a) FAD+ b) NAD+ c) ATP d) NADP+

ATP

Streptococcus bacteria lack an electron transport chain. How many molecules of ATP can a Streptococcus cell net from one molecule of glucose? a) 1 b) 2 c) 10 d) 36 e) 38

2

For every NADH that is oxidized via the electron transport chain, _____ ATP(s) is/are formed.

3

At the completion of aerobic respiration, energy has been formed. The energy from the oxidation of glucose is stored in _____.

ATP

Which of the following statements accurately describes the difference between aerobic and anaerobic respiration? a) Anaerobic respiration uses oxygen as the final electron acceptor, and aerobic respiration uses either an inorganic molecule, such as nitrate ions or sulfate ions, or an organic molecule, such as an acid or alcohol. b) Aerobic respiration uses O2 as the final electron acceptor, whereas anaerobic respiration uses H2O. c) Aerobic respiration uses oxygen as the final electron acceptor, and anaerobic respiration uses either an inorganic molecule, such as nitrate ions or sulfate ions, or an organic molecule, such as an acid or alcohol. d) Aerobic respiration uses an organic molecule as the final electron acceptor, and anaerobic respiration uses an inorganic molecule as the final electron acceptor.

Aerobic respiration uses oxygen as the final electron acceptor, and anaerobic respiration uses either an inorganic molecule, such as nitrate ions or sulfate ions, or an organic molecule, such as an acid or alcohol

At the completion of the Krebs cycle, the carbons from glucose are in _____. (Name the molecule.)

CO2

Which of the following is true of catabolism? a) Catabolic reactions are exergonic; they break down complex organic molecules into simpler ones. b) Catabolic reactions build up complex organic compounds from simpler ones. c) An example of a catabolism is the creation of sugar from carbon dioxide and water. d) Catabolic reactions use energy from ATP, converting it to ADP.

Catabolic reactions are exergonic; they break down complex organic molecules into simpler ones

When fermentation tests are used to help identify bacteria, which of the following end-products is typically detected by a color change? O2 NADP acid gas

acid

Some amino acids are synthesized by adding an amine group to pyruvic acid or to one of the Krebs cycle intermediates. This process is known as __________. catabolism hydrolysis amination carbon fixation

amination

Which of the following terms refers to pathways that can function in both anabolism and catabolism? a) homolactic fermentation pathways b) light-dependent pathways c) amphibolic pathways d) chemiosmotic pathways

amphibolic pathways

The proton motive force is __________. an electrochemical gradient formed across a membrane the movement of water across a membrane ATP accumulation in the mitochondria the movement of flagella the accumulation of water formed in respiration

an electrochemical gradient formed across a membrane

Nitrobacter bacteria use carbon dioxide for their carbon source and nitrate ions as an energy source. This organism is a __________. a) chemoautotroph b) photoautotroph c) chemoheterotroph d) photoheterotroph

chemoautotroph

Organisms that use carbon dioxide as a carbon source and ammonia or hydrogen sulfide as energy sources are called __________. saprophytes photoautotrophs chemoautotrophs chemoheterotrophs photoheterotrophs

chemoautotrophs

In cyclic photophosphorylation, electrons released from excited chlorophyll molecules eventually return to _____.

chlorophyll

Competitive inhibition of enzyme action involves __________. irreversible binding to the enzyme's active site competition for binding at the enzyme's allosteric site competition with the substrate for binding at the active site alteration of the enzyme's active site destruction of the enzyme's substrate

competition with the substrate for binding at the active site

A coenzyme assists an enzyme by accepting or donating matter. What does NAD+ transfer? acetyl CoA phosphate groups electrons acetyl groups ATP

electrons

Anaerobic respiration is another name for fermentation.

f

Both DNA and RNA are required for protein synthesis.

f

Feedback inhibition generally acts on the last enzyme in an anabolic pathway.

f

Glycolysis produces ATP through oxidative phosphorylation

f

Lipids, proteins, and sugars all may serve as substrates of glycolysis.

f

You inoculated an unknown strain of E. coli into a medium containing sorbitol. Your test is positive for sorbitol fermentation. You conclude that your strain is the pathogenic strain E. coli O157.

f

Which one molecule could provide the carbon source, the energy source, and the electron source for a chemoheterotroph? sulfur nitrogen glucose ATP carbon dioxide

glucose

In fermentation, ATP is generated only in _____. (Name the pathway.)

glycolysis

Unlike chemiosmosis in eukaryotes, prokaryotes chemiosmosis __________. moves iron instead of protons across the membrane does not require a membrane occurs at the plasma membrane and not the mitochondria does not require ATP synthase electrons are eventually passed to organic molecules instead of inorganic acceptors

occurs at the plasma membrane and not the mitochondria

Which of the following pairs is NOT correctly matched? a) anabolism; building of complex molecules b) metabolic pathways; sequences of chemical reactions c) oxidation; reaction in which electrons are gained d) catabolism; breakdown of organic compounds e) metabolism; sum of all chemical reactions

oxidation; reaction in which electrons are gained

Which of the following four stages of glucose oxidation during aerobic respiration requires molecular oxygen? production of acetyl CoA oxidative phosphorylation glycolysis Krebs cycle

oxidative phosphorylation

Heterotrophs use organic molecules as energy and carbon sources. To produce five-carbon intermediates needed for synthesis of nucleic acids, the cell utilizes the __________. Krebs cycle glycolytic pathway mixed acid fermentation pathway pentose phosphate pathway cyclic photophosphorylation pathway

pentose phosphate pathway

You isolated an unknown that uses CO2 as carbon source and also uses H2O to reduce CO2. The organism is a(n) __________.

photoautotroph

Which organism is NOT correctly matched to its energy source? anoxygenic autotroph; light photoautotroph; CO2 photoheterotroph; light chemoautotroph; iron chemoheterotroph; glucose

photoautotroph; CO2

Carbon fixation occurs during __________. fermentation glycolysis photosynthesis the complete oxidation of glucose

photosynthesis

At the completion of glycolysis, the carbons from glucose are in _____ . (Name the molecule.)

pyruvate

All of the following are potential end-products of fermentation EXCEPT __________. lactic acid pyruvic acid ethanol carbon dioxide acetic acid

pyruvic acid