GBIO 106 Chapter 6
Select reactions that occur during the first stage of glycolysis, called the energy investment stage, which consists of the first five reactions.
1. A 6-carbon intermediate is split into two 3-carbon molecules. 2. Phosphate is transferred to glucose.
Rank the types of metabolic pathways from smallest ATP production (at the top) to largest production of ATP (at the bottom). fermentation aerobic respiration anaerobic respiration
1. fermentation 2. anaerobic respiration 3. aerobic respiration
Rank the 3 groups of reactions of aerobic respiration in the order they occur, beginning with the first stage of cellular respiration at the top: Krebs cycle, electron transport chain, and glycolysis
1. glycolysis 2. Krebs cycle 3. electron transport chain
Rank the following pathways in the order that they likely evolved, from the first one to evolve at the top to the last one to evolve at the bottom: photosynthesis using H2O as electron donor aerobic respiration glycolysis photosynthesis using H2S as electron donor
1. glycolysis 2. photosynthesis using H2S as electron donor 3. photosynthesis using H2O as electron donor 4. aerobic respiration
Rank the 3 groups of reactions of aerobic respiration in the order they occur, beginning with the first stage of cellular respiration at the top. electron transport chain Krebs cycle glycolysis
1. glycolysis 2. Krebs cycle 3. electron transport chain
Pyruvate is the product of glycolysis, and after it moves into the _________________, it is oxidized to form _____________ that enters the Krebs cycle.
Mitochondrial matrix; acetyl CoA
In lactic acid fermentation, NADH reduces pyruvate, and the products are ______________ and lactic acid.
NAD+
During fermentation, ________________ reduces pyruvate and is oxidized to NAD+, which can then be used in glycolysis.
NADH
The electron transport chain harnesses the potential energy of the molecules ___________, which donate electrons to proteins in the electron transport chain.
NADH and FADH2
The rearrangement and oxidation of intermediates in the Krebs cycle transfers electrons to what molecules?
NADH and FADH2
Select all the products of glycolysis and the Krebs cycle that carry electrons to the electron transport chain in aerobic respiration.
NADH, FADH2
Select the molecules that are products of the Krebs cycle.
NADH, FADH2, ATP, and carbon dioxide
Select all of the following that are true of ATP synthesis.
a phospate group is added to ADP, requires an input of energy (endergonic reaction)
The fatty acids of fat molecules are converted into two-carbon molecules called _____________, which can enter the Krebs cycle of aerobic respiration.
acetyl CoA
What product of pyruvate oxidation enters the Krebs cycle?
acetyl CoA
Select all of the following that are outputs of pyruvate oxidation during the "transition step" of cellular respiration.
acetyl CoA, CO2, NADH
C6H12O6 + 6O2 -----> 6CO2 + 6H2O + 36ATP
aerobic respiration
What cellular process uses glucose and oxygen to produce ATP?
aerobic respiration
What cellular process generates ATP and uses an inorganic molecule other than oxygen as the final electron acceptor of the electron transport chain?
anaerobic respiration
Two types of pathways that generate ATP from glucose without oxygen are __________________ respiration and __________________.
anaerobic, fermentaton
The Krebs cycle produces ATP, NADH, FADH2, and releases _____________, which contains the carbon atoms remaining from the original 6-carbon glucose molecule.
carbon dioxide
Select the molecules that are products of the Krebs cycle
carbon dioxide, NADH, FADH2, and ATP
In substrate-level phosphorylation, a molecule donates a(n) _____________ group to ADP to form ATP, and a ________________ is not required.
phosphate; proton gradient
Although the theoretical yield of ATP per one molecule of glucose in aerobic respiration is about 36 ATP, the actual yield is about _____ ATP per glucose.
30
Before the NADH and FADH2 produced during glycolysis and the Krebs cycle are "cashed in" during the electron transport chain, the net number of ATP molecules produced per glucose molecule is _____ molecules.
4
ATP synthase is an enzyme that forms a channel for hydrogen ions to diffuse across a membrane and power the formation of
ATP
The potential energy stored in food (such as glucose) is used by all organisms to make the energy-carrying molecule ______________, which powers cellular activity.
ATP
What causes the difference between the theoretical and actual yields of ATP in aerobic respiration? Select all that apply.
ATP is spent transporting pyruvate and ADP into the mitochondrial matrix. Protons leak across the inner mitochondrial membrane without using ATP synthase.
What enzyme uses the energy of a proton gradient to combine a phosphate and ADP?
ATP synthase
Select all of the following that are encoded by mitochondrial DNA.
ATP synthase, proteins of the electron transport chain.
Glycolysis generates 4 ____________ molecules per glucose, but requires an input of ___________ ATP molecule(s), producing a net of 2 ATP molecules per glucose.
ATP, 2
Match the term with the correct description concerning food and energy.
ATP: supplies power to almost all cellular activities requiring energy photosynthesis: uses light energy to produce food in the form of glucose cellular respiration: converts the energy in food to an energy-carrying molecule
Anaerobic respiration and fermentation are two pathways that generate __________ in the absence of ____________.
ATP; oxygen
After glycolysis, oxidation of pyruvate, and the Krebs cycle occur, and before molecules enter the electron transport chain, what has been produced from the original glucose molecule? Select all that apply.
CO2, NADH, FADH2, and ATP
What happens to the lactate produced by muscle cells that conduct fermentation to acquire ATP?
Cells consume it within a short time.
The electron transport chain accepts energy-rich electrons from the ________ and __________ produced in the previous reactions of aerobic respiration.
FADH2 and NADH
Match each product or result with its type of anaerobic respiration.
H2S byproduct: wetland bacteria that use SO4 as the electron acceptor in anaerobic respiration generate menthane: archaea inside cow intestines that use CO2 as the electron acceptor in aerobic respiration results in production of nitrogen gas: bacteria living in water-logged soils that use NO3 as the electron acceptor in aerobic respiration
Categorize each molecule as an input or output of the "transition step" in aerobic cellular respiration.
Input: NAD+, pyruvate Output: Acetyl CoA, NADH, and carbon dioxide
Match the aerobic respiration step with the correct location where it occurs in the cell in the prokaryotes (bacteria and archaea) and eukaryotes.
Krebs cycle in prokaryotes: cytosol Krebs cycle in eukaryotes: mitochondrial matrix electron transport in prokaryotes: cell membrane electron transport in eukaryotes: inner mitochondrial membrane
Select all of the following that are stages of aerobic cellular respiration.
Krebs cycle, electron transport chain, and glycolysis
Select all of the following that are true about alcholic fermentation.
Pyruvate is converted to ethanol and CO2. NAD+ is produced.
Categorize the molecules as reactants or products in the overall equation for aerobic respiration: 02 (oxygen) CO2 (carbon dioxide) H20 (water) C6H12O6 (glucose) ATP (adenosine triphosphate)
Reactant: C6H12O6, Oxygen Product: CO2, ATP, and H2O
Categorize the molecules as reactants or products of glycolysis.
Reactant: NAD+, glucose Product: NADH, pyruvate
Categorize the molecules as reactants or products of glycolysis: NAD+ glucose NADH pyruvate
Reactant: NAD+, pyruvate Product: NADH, glucose
Categorize the molecules as reactants or products in the overall equation for aerobic respiration: adenosine triphosphate, glucose, oxygen, and carbon dioxide.
Reactant: O2 (oxegyn), C6H12O6 (glucose) Product: ATP (adenosine triphosphate), CO2 (carbon dioxide)
Select all of the following that are true of ATP synthesis.
Requires an input of energy (endergonic reaction), a phosphate group is added to ADP.
Match the pathway of aerobic respiration with the correct method of ATP generation. glycolysis Krebs cycle electron transport
Substrate-level phosphorlylation: glycolysis, Krebs cycle Chemiosmotic phosphorylation: electron transport
True or false: The potential energy stored in glucose cannot be removed all at once or it will cause destruction of the cell.
True
True or false: Plants use a portion of the glucose they produce in photosynthesis to make ATP in cellular respiration.
True.
Select reactions that occur during the second stage of glycolysis, called the energy harvest stage and consisting of reactions 6 through 10.
Two molecules of pyruvate are produced. NAD+ is reduced to NADH. ATP is generated by substrate-level phosphorylation.
Which of the following can be a final electron acceptor in anaerobic respiration? Select all that apply.
carbon dioxide, sulfate, nitrate
When protons diffuse across the membrane through ATP synthase, energy is transferred to phosphorylate an ADP, making ATP in the process called
chemiosmotic phosphorylation
The first product of the Krebs cycle is the 6-carbon molecule citrate; hence, the Krebs cycle is also known as the _____________ acid cycle.
citric
The first product of the Krebs cycle is the 6-carbon molecule citrate; hence, the Krebs cycle is also known as the
citric acid cycle.
What step of aerobic respiration generates the most ATP?
electron transport chain
Select all of the following that are stages of aerobic cellular respiration.
electron transport chain, Krebs cycle, glycolysis
NADH and FADH2 transfer energy-rich ____________ from the molecules of glycolysis and the Krebs cycle to the electron transport chain of aerobic respiration.
electrons
NADH and FADH2 transfer energy-rich __________________ from the molecules of glycolysis and the Krebs cycle to the electron transport chain of aerobic respiration.
electrons
Two pathways that cells use to make ATP from glucose without oxygen are anaerobic respiration and
fermentation.
Cellular respiration harvests energy from ______________ and uses the energy to power the ______________ reaction of ATP sythesis from ADP and a phosphate group.
food molecules; endergonic
The organic product of photosynthesis, ________________, is the reactant of cellular respiration.
glucose
During which step of cellular respiration is glucose split into two 3-carbon pyruvate molecules?
glycolysis
In the electron transport chain, energy from electron transfers powers the pumping of ___________________ into the intermembrane compartment by some of the proteins in the chain.
hydrogen ions
Glycolysis can occur
in both aerobic and anaerobic conditions
Within mitochondria, the electron transport chain and ATP synthase proteins are located in the
inner mitochondrial membrane
The area between the outer and inner membranes of a mitochondrion is called the
intermembrane compartment
When there is no oxygen available to human muscle cells, the cells can continue to make ATP for a short time using glycolysis as part of
lactic acid fermentation
In the cells of protists, plants, fungi, and animals, the Krebs cycle and the electron transport chain take place in organelles called
mitochondria
Select all the organelles that contain electron transport chains within their inner membranes or inner compartments and that are likely to have arisen from endosymbiosis of bacteria with electron transport chains on their cell membranes.
mitochondria and chloroplasts
The space enclosed within the inner membrane of a mitochondrion is called the
mitochondrial matrix
Which of the following can be a final electron acceptor in anaerobic respiration? Select all that apply.
nitrate, sulfate, and carbon dioxide
When carbohydrate supplies are depleted in cells, amino acids from proteins can enter aerobic respiration after ____________ is removed from the amino acid and excreted.
nitrogen
Which of the following components is not required for glycolysis to occur?
oxygen
In glycolysis, a glucose molecule is split into two molecules of _____________, and energy is harvested as ATP and NADH.
pyruvate
After nitrogen is removed from the amino acids in protein-containing foods, the remainder of the amino acids can enter aerobic respiration pathways as what molecules? Select all that apply.
pyruvate, an intermediate in the Krebs cycle, acetyl CoA
What types of organisms can rely on fermentation as the sole pathway for producing ATP?
single-celled organisms, microorganisms in sugar-rich environment
Select organisms that are able to generate ATP by conducting anaerobic respiration, which includes an electron transport chain, but an inorganic molecule other than oxygen is the electron acceptor at the end of the electron transport chain.
some bacteria, some archaeans
Select all the food molecules that can be broken down into glucose monomers, which enter aerobic respiration at the beginning of glycolysis.
starch and glycogen
What method is used to generate ATP in glycolysis?
substrate-level phosphorylation
When the electron carrier molecules NADH and FAD2 enter ______________, electrons are removed, and the energy pumps protons into the intermembrane compartment of the mitochondrion.
the electron transport chain
Match each component of aerobic respiration with the correct number of ATP generated during the passage of one molecule of glucose: theortetical total glycolysis Krebs cycle electron transport
theoretical total: 36 ATP glycolysis: produces 4 ATP but requires 2 ATP; so net 2 ATP are produced Krebs cycle: 2 ATP electron transport: 34 ATP