Chapter 9 Exam 3

What amount of free energy is released by the oxidation of 2 moles of NADH? 7.3 kcal 14.6 kcal 21.9 kcal 52.4 kcal 104.8 kcal

104.8 kcal

What is the net free energy captured by 32 moles of ATP? 7.3 kcal 52.4 kcal 234 kcal 686 kcal 730 kcal

234 kcal

Approximately how many ATP molecules per glucose molecule are produced via glycolysis and cellular respiration? 2 4 8 16 32

32

Oxidative phosphorylation has two major components: _______ and _______. proton transport; chemiosmosis electron transport; chemical reduction electron transport; osmosis proton transport; energy coupling electron transport; chemiosmosis

electron transport; chemiosmosis

The types of chemical reactions involved in the aerobic breakdown of glucose by a cell include reductions and phosphorylations. oxidations. reductions. oxidations and phosphorylations. oxidation-reduction reactions and phosphorylations.

oxidation-reduction reactions and phosphorylations.

The reaction equation that represents the chemical change resulting from glycolysis followed by cellular respiration is C6H12O6 + 6 O2 → 6 CO2 + _______ ATP + 6 _______. 2; H2O 2; NADH 16; H2O 32; H2O 32; NADH

32; H2O

A student wants to develop a demonstration to explain the energy changes taking place as electrons are transferred along the respiratory chain. Which everyday objects could he use to accomplish his goal? A hot plate boiling water in a pot A bat striking a ball A ball rolling down a staircase A book falling from a table to the floor An ice cube melting in a bowl

A ball rolling down a staircase

Some poisons are compounds that interfere with metabolic pathways. Which poison would interfere with the citric acid cycle but not affect glycolysis? A compound that inhibits regeneration of NAD+ from NADH A compound that accelerates coenzyme A synthesis A compound that inhibits pyruvate dehydrogenase A compound that accelerates ATP hydrolysis A compound that accelerates pyruvate oxidation

A compound that inhibits pyruvate dehydrogenase

The carbon-containing molecule that enters glycolysis differs from the one that enters the citric acid cycle. How do the numbers of carbon atoms per molecule compare in these two cases? A six-carbon molecule enters glycolysis, while a two-carbon molecule enters the citric acid cycle. A six-carbon molecule enters glycolysis, while a four-carbon molecule enters the citric acid cycle. A six-carbon molecule enters glycolysis, while a three-carbon molecule enters the citric acid cycle. A four-carbon molecule enters glycolysis, while a three-carbon molecule enters the citric acid cycle. A four-carbon molecule enters glycolysis, while a two-carbon molecule enters the citric acid cycle.

A six-carbon molecule enters glycolysis, while a two-carbon molecule enters the citric acid cycle.

Which reaction is not an example of an oxidation-reduction reaction? CH4 + ½ O2 → CH3OH + H+ NADH + H+ + ½ O2 → NAD+ + H2O C2H5OH + NAD+ → C2H4O + NADH + H+ ADP + Pi → ATP + H2O C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

ADP + Pi → ATP + H2O

Which component of the respiratory chain is a peripheral protein? Complex I Complex II Complex III Complex IV Cytochrome c

Cytochrome c

The cell harvests a very large amount of free energy from glucose in the form of ATP. Which statement can be used as part of an explanation about how the cell accomplishes this harvesting process with high efficiency (i.e., with very little loss in energy as heat)? NADH and FADH2 enter the electron transport chain at different points. Electron flow through the respiratory chain results in the active transport of protons across the inner mitochondrial membrane, creating a proton concentration gradient. Pyruvate oxidation and the citric acid cycle cannot operate unless oxygen is available to function as the final acceptor of electrons. The net energy change for the transfer of electrons from NADH to oxygen is very large. Electron transport uses a series of several proteins, each of which functions to capture a portion of the total energy of the electrons entering the chain.

Electron transport uses a series of several proteins, each of which functions to capture a portion of the total energy of the electrons entering the chain.

Complete the following reaction found in the NADH shuttle mechanism in some eukaryotic cells: FAD + glycerol 3-phosphate → _______ + DHAP. . FADH glycerol FADH2 FADH2 + NAD+ FADH2 + NADH

FADH2

Electrons are shuttled from glycolysis and the citric acid cycle to the respiratory chain via ATP. FADH2 only. GTP. FADH2 and NADH. NADH only.

FADH2 and NADH.

Products from the citric acid cycle include GDP. ATP. FADH2. NAD+. acetyl CoA.

FADH2.

Which describes how the components of the respiratory chain are ordered? From high to low ability to pump protons across the inner membrane From high to low reduction potential relative to oxygen From low to high free energy relative to oxygen From large to small mass From low to high ability to pass electrons to oxygen

From high to low reduction potential relative to oxygen

In eukaryotes, the proton-motive force allows protons to move passively through ATP synthase in which direction? From the mitochondrial inner membrane space to the mitochondrial matrix From the cytoplasm to the mitochondrial inner membrane space From the cytoplasm to the mitochondrial matrix From the mitochondrial matrix to the inner mitochondrial membrane space From the outside of the cell to the cytosol

From the mitochondrial inner membrane space to the mitochondrial matrix

Which list places the molecules, from left to right, from most oxidized to least oxidized? CO2 > CH2O > HCOOH > CH4 HCOOH > CH4 > CH3OH > CO2 CO2 > CHOOH > CH3OH > CH4 CH2O > CO2 > CH3OH > CH4 CH4 > CH3OH > CHOOH > CO2

CO2 > CHOOH > CH3OH > CH4

Pyruvate oxidation to acetyl CoA is a complex reaction because one pyruvate molecule is oxidized to another three-carbon compound. it requires the input of energy. it is located in the mitochondrial matrix. it involves the transfer of acetyl CoA to oxaloacetate. it is a multistep chemical reaction involving five different coenzymes and 60 individual proteins.

it is a multistep chemical reaction involving five different coenzymes and 60 individual proteins.

Metabolic pathways are resistant to inhibitors and activators. small sets of chemical reactions that are always taking place in every cell. large sets of interconnected chemical transformational steps, each with a specific enzyme. ways of creating energy for a cell. not regulated.

large sets of interconnected chemical transformational steps, each with a specific enzyme.

When a person runs for an extended period of time, the main source of glucose for muscle cells comes from the breakdown of glycogen in the lungs. muscle. liver. electron transport chain. heart.

liver

How are steps 1-3 of glycolysis different from steps 6-10? Steps 1-3 catalyze reactions that require ATP, while steps 6-10 catalyze changes that produce NADH and GTP. Steps 1-3 catalyze reactions that require ATP, while steps 6-10 catalyze changes that produce NADH and ATP. Steps 1-3 catalyze reactions that require ATP, while steps 6-10 catalyze changes that require NADH. Steps 1-3 catalyze changes in a six-carbon molecule, while steps 6-10 catalyze changes in a four-carbon molecule. Steps 1-3 occur in the cytosol, while steps 6-10 occur in the mitochondrial matrix.

Steps 1-3 catalyze reactions that require ATP, while steps 6-10 catalyze changes that produce NADH and ATP.

Energy production occurs in different locations in prokaryotic and eukaryotic cells. Which statement is true for eukaryotes? The conversion of glucose to pyruvate occurs in the mitochondria. The citric acid cycle enzymes are found in the cytoplasm. The conversion of pyruvate to lactate occurs in the mitochondria. The conversion of pyruvate to CO2 and H2O occurs in the mitochondria. The respiratory chain enzymes are found at the plasma membrane.

The conversion of pyruvate to CO2 and H2O occurs in the mitochondria.

Which statement best describes steps 1, 2, and 3 of glycolysis (glucose → glucose 6-phosphate → fructose 1,6-bisphosphate)? All three reactions are exergonic. These reactions require energy in the form of one ATP per glucose. These reactions produce energy in the form of one NADH per glucose. A six-carbon molecule is broken down into three two-carbon molecules. These reactions require energy in the form of two ATP per glucose molecule.

These reactions require energy in the form of two ATP per glucose molecule.

Under anaerobic conditions, pyruvate Please choose the correct answer from the following choices, and then select the submit answer button. is broken down on the cell membrane. is reduced to lactate. enters the citric acid cycle. is fermented to lactate or alcohol. is converted to lactate or tricarboxylic acids.

is fermented to lactate or alcohol.

Which sequence of metabolic paths could a carbon atom take to go from a molecule of glucose to a molecule of DNA? Glycolysis → glycerol biosynthesis → triglyceride biosynthesis → fatty acid biosynthesis → citric acid cycle Glycolysis → pyruvate oxidation → citric acid cycle → electron transport → ATP synthesis Glycolysis → amino acid biosynthesis → protein biosynthesis → citric acid cycle → acetyl CoA synthesis Glycolysis → amino acid biosynthesis → citric acid cycle → acetyl CoA synthesis → nucleic acid biosynthesis Glycolysis → pyruvate oxidation → citric acid cycle → amino acid biosynthesis → purine biosynthesis

Glycolysis → pyruvate oxidation → citric acid cycle → amino acid biosynthesis → purine biosynthesis

A biochemist discovers several new microorganisms in a sample taken from the bottom of a deep lake in Antarctica. In characterizing one of these organisms, she finds that it cannot survive in an aerobic environment and produces lactic acid as a waste product. What is also likely true about this organism? It expresses all of the respiratory chain proteins. It is able to oxidize pyruvate to acetyl CoA. It lacks genes for the glycolytic enzymes. It is able to oxidize glucose to carbon dioxide. It lacks genes for citric acid cycle enzymes.

It lacks genes for citric acid cycle enzymes.

Some of the chemical energy present in pyruvate is harvested during an oxidation-reduction process taking place in the multistep reaction shown in the figure. In which molecule is this harvested chemical energy stored? CO2 NADH Coenzyme A NAD+ Pyruvate

NADH

Which statement best describes how key molecules are regenerated to allow continued metabolism in a cell? GTP can donate its electrons to the electron transport chain and be regenerated to allow pyruvate oxidation to continue. GTP, NADH, and FADH2 can donate their electrons to the electron transport chain and be regenerated to allow the citric acid cycle to continue. FADH2 can donate its electrons to the electron transport chain and be regenerated to allow glycolysis to continue. ATP can donate its electrons to the electron transport chain and be regenerated to allow the citric acid cycle to continue. NADH and FADH2 can donate their electrons to the electron transport chain and be regenerated to allow the citric acid cycle to continue.

NADH and FADH2 can donate their electrons to the electron transport chain and be regenerated to allow the citric acid cycle to continue.

Malate dehydrogenase is responsible for catalyzing which reaction? Oxidation of NADH to NAD+ Substrate phosphorylation of ADP to ATP Reduction of malate to oxaloacetate Oxidation of malate to oxaloacetate Decarboxylation of a five-carbon molecule to a four-carbon molecule

Oxidation of malate to oxaloacetate

Which statement regarding glycolysis is true? Glucose is not catabolized. Oxygen is not required. Pyruvate is not formed. NADH is not formed. ATP is not formed.

Oxygen is not required.

Which statement regarding glycolysis is true? Two molecules of glucose are catabolized to form two molecules of pyruvate. The first two steps are endergonic. Two ATP molecules are required in the first three steps per glucose molecule. ATP is not formed. NADH is not formed.

Two ATP molecules are required in the first three steps per glucose molecule.

Catabolic interconversion is a metabolic pathway in which many small molecules are combined into larger molecules and a pathway that requires energy. large molecules are built up into even larger molecules and a pathway that requires energy. a large molecule is broken down into its constituent molecules and releases energy. small molecules are broken down into CO2 and water molecules and release energy. a citric acid intermediate is a starting point.

a large molecule is broken down into its constituent molecules and releases energy.

ATP synthase is the protein complex that transfers electrons to oxygen in the final step of the respiratory chain. rotates when ATP is hydrolyzed in the mitochondrial matrix. creates a proton-motive force when glucose is oxidized. captures the potential energy of the proton gradient in the intermembrane space as the chemical energy in phosphate bonds of ATP. transfers electrons from the inner mitochondrial space to the mitochondrial matrix.

captures the potential energy of the proton gradient in the intermembrane space as the chemical energy in phosphate bonds of ATP.