WorksheetsChapter 5 Cell and Dev
Total questions: 83
Worksheet time: 42mins
Which process involves the direct transfer of a high energy phosphate from a donor molecule to produce ATP?
Substrate-level phosphorylation
Oxidative phosphorylation
Photophosphorylation
Chemiosmosis
What is the main site within the mitochondrion where the machinery for ATP synthesis is located?
Cristae
Outer membrane
Intermembrane space
Matrix
Which of the following best describes the structure of a typical mitochondrion?
Bean-shaped organelle with a double membrane
Spherical organelle with a single membrane
Threadlike organelle with no membrane
Disk-shaped organelle with a triple membrane
What is the function of the mitochondrial matrix?
It contains DNA, ribosomes, and enzymes for protein synthesis.
It stores calcium ions for muscle contraction.
It is the site of photosynthesis.
It produces glucose from carbon dioxide.
How does the size and number of mitochondria in a cell relate to its function?
They reflect the energy requirements of the cell.
They determine the cell’s ability to divide.
They control the cell’s water content.
They regulate the cell’s genetic material.
Which process is responsible for the aerobic production of ATP in mitochondria?
Oxidative phosphorylation
Substrate-level phosphorylation
Glycolysis
Fermentation
A muscle cell rapidly generates ATP using stored creatine phosphate (CrP). Which reaction represents this process?
CrP + ADP → Cr + ATP
ATP + Cr → CrP + ADP
Glucose + ADP → ATP + Pyruvate
NADH + O2 → NAD+ + H2O
Why do heart muscle cells have a high percentage of their cytoplasm occupied by mitochondria?
They have high energy requirements.
They need to store large amounts of calcium.
They are involved in immune responses.
They synthesize large amounts of lipids.
Which of the following is NOT a function of the mitochondrial matrix?
Site of photosynthesis
Contains circular DNA
Contains ribosomes
Contains enzymes for protein synthesis
What is the significance of the cristae in the inner mitochondrial membrane?
They increase the surface area for ATP synthesis.
They store genetic material.
They transport proteins out of the mitochondrion.
They produce glucose.
What is the approximate protein content of the outer mitochondrial membrane?
About 50% protein
About 10% protein
About 75% protein
About 90% protein
Which protein forms large pores in the outer mitochondrial membrane, allowing moderately sized molecules to cross?
Porin
Cardiolipin
Cytochrome c
ATP synthase
The inner mitochondrial membrane is impermeable to which of the following?
Even small molecules
Large proteins only
Water only
Glucose only
Which lipid is found in the inner mitochondrial membrane but not cholesterol?
Cardiolipin
Sphingomyelin
Phosphatidylcholine
Triglyceride
The inner mitochondrial membrane has characteristics in common with which type of cell membrane?
Bacterial cell membrane
Cardiac muscle cell membrane
Plant cell membrane
Neuronal cell membrane
During carbohydrate metabolism in eukaryotic cells, what process occurs in the absence of oxygen?
Fermentation
Glycolysis
TCA cycle
Electron transport chain
What is the final product when pyruvate is completely oxidized in the tricarboxylic acid (TCA) cycle?
Carbon dioxide (CO₂)
Lactate
Glucose
Oxygen
How many pairs of electrons are transferred to NAD+ and FAD+ per pyruvate in the TCA cycle?
5 pairs
2 pairs
3 pairs
7 pairs
What is the main purpose of high energy electrons generated in the TCA cycle?
To generate ATP
To synthesize glucose
To produce lactate
To form pyruvate
Which process in eukaryotic cells converts glucose to pyruvate in the cytosol?
Glycolysis
Fermentation
TCA cycle
Electron transport chain
The diagram shows the structure of the outer mitochondrial membrane with a porin protein forming a pore for passage of which type of molecules?
Large proteins
Moderate-sized molecules
Ions only
DNA strands
Refer to the diagram illustrating carbohydrate metabolism in eukaryotic cells, including glycolysis, fermentation, and the TCA cycle. Which process produces the most ATP?
Glycolysis
Fermentation
TCA cycle
Electron transport chain
Refer to the diagram of the tricarboxylic acid (TCA) cycle, showing the stepwise oxidation of substrate and transfer of electrons. Which process is primarily illustrated by this cycle?
Glycolysis
Electron transport chain
Citric acid cycle
Pentose phosphate pathway
What is the main function of ATP in oxidative phosphorylation?
To store genetic information
To provide energy for cellular processes
To transport electrons
To synthesize proteins
Which molecule acts as the final electron acceptor in the electron transport chain?
NADH
FADH2
O2
CO2
How many molecules of ATP are formed from each pair of electrons donated by NADH during oxidative phosphorylation?
1
2
3
4
Which type of electron carrier contains heme groups bearing Fe or Cu metal ions?
Flavoproteins
Cytochromes
Ubiquinone
Coenzyme A
What is the role of ubiquinone (coenzyme Q) in the electron transport chain?
It is a protein-bound electron carrier
It is a lipid-soluble molecule that transfers electrons
It binds oxygen for ATP synthesis
It synthesizes NADH
Which electron-transport complex catalyzes the transfer of electrons from NADH to ubiquinone?
Complex I (NADH dehydrogenase)
Complex II (succinate dehydrogenase)
Complex III (cytochrome bc1)
Complex IV (cytochrome c oxidase)
What is the effect of metabolic poisons such as CO, N3-, and CN- on the electron transport chain?
They enhance ATP synthesis
They bind catalytic sites in Complex IV and inhibit function
They increase electron flow
They activate cytochrome oxidase
Explain how chemiosmosis is coupled to ATP synthesis in oxidative phosphorylation.
H+ ions are pumped into the cytoplasm to form ATP
The movement of H+ back across the membrane drives ATP synthesis
Electrons directly combine with ADP to form ATP
Oxygen is converted into ATP by electron carriers
Which complex in the electron transport chain catalyzes the transfer of electrons to O2 and transports H+ across the inner membrane?
Complex I
Complex II
Complex III
Complex IV
Why are three copper atoms important in electron transport complexes?
They bind oxygen for ATP synthesis
They alternate between Cu2+/Cu3+ states to facilitate electron transfer
They synthesize NADH
They transport H+ ions directly
From an energy standpoint, are the reactions in the electron transport chain endergonic or exergonic?
Endergonic
Exergonic
Some are exergonic and others are endergonic.
There is not enough information.
What is the order of arrangement for electron carriers in the electron-transport chain of the inner mitochondrial membrane?
In order of increasingly negative redox potential.
In order of increasingly positive redox potential.
In order of decreasing molecular weight.
In order of decreasing catalytic activity.
Which experimental method is used to determine the sequence of electron carriers in the electron-transport chain?
Use of inhibitors.
Use of fluorescent markers.
Use of radioactive isotopes.
Use of temperature gradients.
What does the tendency for electrons to be transferred from one carrier to the next depend on?
The molecular weight of the carrier.
The potential difference between the two redox centers.
The temperature of the mitochondria.
The pH of the matrix.
What is the role of cytochrome oxidase in the electron transport chain?
It transfers electrons directly to NADH.
It adds four electrons to O₂ to form two molecules of H₂O.
It removes protons from the matrix.
It synthesizes ATP from ADP.
How do electrons probably flow through the electron transport chain?
By jumping directly from one carrier to another.
Through special "tunneling pathways" of covalent and hydrogen bonds.
By diffusing freely in the intermembrane space.
By being carried by ATP molecules.
Which of the following is NOT a function of cytochrome oxidase in the electron transport chain?
Adding four electrons to O₂ to form H₂O.
Transferring electrons one at a time.
Promoting movement of H⁺ ions through the protein.
Synthesizing glucose from pyruvate.
Why is the energy released by O₂ reduction important in the electron transport chain?
It drives conformational changes in protein complexes.
It increases the temperature of the mitochondria.
It synthesizes DNA.
It breaks down fatty acids.
Electrons may travel large distances between adjacent redox centers. What is the typical range for these distances?
1–5 Å
10–20 Å
50–100 Å
100–200 Å
What would happen to the flow of electrons if oxygen were not present?
The flow of electrons would continue but at a slower rate.
The flow would cease and ATP production would stop.
The absence of oxygen would have no effect.
The flow of electrons would increase rapidly.
Electron transport produces a gradient of which ion between the intermembrane space and the matrix?
Na+ ions
K+ ions
H+ ions
Cl- ions
Both the H+ concentration gradient and the charge gradient across the inner mitochondrial membrane create what kind of energy?
Kinetic energy
Chemical energy
Potential energy
Thermal energy
Which complexes will be completely reduced in the presence of rotenone, an inhibitor that blocks the transfer of electrons along the chain?
Only complex I
Complex I and II
Only complex III and IV
All of them (complexes I – IV)
None of them
Inhibitors block the transfer of electrons along the chain. Which complexes will be completely reduced in the presence of Cyanide?
Only complex I
Complex I and II
Only complex III and IV
All of them (complexes I – IV)
None of them
Cyanide blocks final transfer of electrons to O₂. What will happen?
Reduced ATP yield
Only Glycolysis & Krebs Cycle continue
Only Glycolysis can continue
Glycolysis & fermentation can continue
Zero ATP produced
What is the effect of Dinitrophenol (DNP) on glucose oxidation and ATP formation?
It couples glucose oxidation and ATP formation
It increases ATP yield by enhancing the proton gradient
It uncouples glucose oxidation and ATP formation by increasing membrane permeability to H⁺
It blocks electron transfer at complex IV
Which of the following is a result of eliminating the proton gradient in mitochondria?
Increased ATP synthesis
Decreased metabolic rate
No ATP formation via chemiosmosis
Enhanced electron transfer
What is the role of uncoupling proteins (UCPs) in brown fat?
They increase ATP production
They generate heat
They block electron transfer
They decrease glucose oxidation
Which of the following creates a pH gradient (ΔpH) in mitochondria?
Concentration gradient between matrix and intermembrane space
Separation of charge across the membrane
Accumulation of ATP in the matrix
Movement of electrons through complex IV
What is the proton-motive force (Δp) in mitochondria?
The force generated by ATP synthase
The energy present in both the pH gradient and electric potential across the membrane
The movement of electrons from NADH to O₂
The gradient of glucose concentration
Fluorescent, cationic dye rhodamine accumulates in active mitochondria due to which property?
High ATP concentration
Voltage inside the mitochondria is negative
Presence of uncoupling proteins
Increased permeability to H⁺
Select the statement that best describes the diagram showing DNP uncoupling the proton gradient and ATP synthase in the mitochondrial membrane.
The diagram illustrates the role of DNP in increasing membrane permeability to H⁺ and uncoupling ATP synthesis.
The diagram shows the Krebs cycle and its intermediates.
The diagram depicts glycolysis in the cytoplasm.
The diagram demonstrates the structure of a ribosome.
Select the statement that best describes the image showing fluorescent rhodamine dye accumulation in active mitochondria due to inside-negative voltage.
The image shows the accumulation of rhodamine dye in active mitochondria due to negative voltage inside.
The image depicts the process of glycolysis.
The image shows the structure of a chloroplast.
The image illustrates the electron transport chain in bacteria.
What is the main source of potential energy used by ATP synthases during chemiosmosis?
The H+ ion gradient
The Na+ ion gradient
The glucose concentration
The oxygen gradient
Which process allows ATP synthase to produce ATP by attaching phosphate groups to ADP?
Chemiosmosis
Glycolysis
Fermentation
Photosynthesis
In which cellular locations is chemiosmosis used to produce ATP?
Mitochondria, chloroplasts, photosynthetic bacteria, bacterial cellular respiration
Nucleus, ribosomes, lysosomes, Golgi apparatus
Cytoplasm, endoplasmic reticulum, peroxisomes, vacuoles
Cell wall, plasma membrane, centrioles, microtubules
How does ATP synthase act when compared to an ATPase ion pump?
It acts in reverse, generating ATP
It acts in the same direction, consuming ATP
It does not interact with ions
It only works in the presence of glucose
What is the role of Coupling factor 1 (F1) in the identification of ATP synthase?
It hydrolyzes ATP in certain conditions and behaves as ATP synthase in others
It synthesizes glucose from pyruvate
It transports oxygen across membranes
It breaks down fatty acids
Why was it concluded that an ionic gradient is important for ATP synthase function?
It establishes a proton-motive force to phosphorylate ADP
It increases the temperature of the cell
It allows DNA replication to occur
It produces ribosomes for protein synthesis
Which two major portions make up the structure of bacterial ATP synthase?
F1 and F0
Alpha and Beta
Gamma and Epsilon
Matrix and Channel
What is the primary function of the F1 particle in ATP synthase?
It acts as the catalytic subunit and contains 3 catalytic sites for ATP synthesis.
It transports protons across the membrane.
It forms the base of the enzyme.
It binds to the mitochondrial DNA.
Which subunit runs from the tip of F1 down to F0 to form a central stalk in ATP synthase?
Gamma (γ) subunit
Alpha (α) subunit
Beta (β) subunit
Epsilon (ε) subunit
What is the role of the epsilon (ε) subunit in ATP synthase?
It helps attach the gamma subunit to the F0 base.
It catalyzes ATP synthesis.
It transports protons.
It forms the spherical head of the particle.
How do protons move through ATP synthase?
Through a channel in the F0 from the intermembrane space to the matrix
Through the F1 subunit only
Across the cytoplasm directly
By binding to the gamma subunit
What is the ratio of the five different subunits in the F1 subunit of ATP synthase?
3 α : 3 β : 1 δ : 1 ε : 1 γ
2 α : 2 β : 2 δ : 2 ε : 2 γ
4 α : 2 β : 1 δ : 1 ε : 1 γ
1 α : 1 β : 1 δ : 1 ε : 1 γ
What causes the shift in conformation of the catalytic subunit in the "Binding Change Mechanism" model of ATP production?
Movement of H+ ions
Movement of Na+ ions
Change in temperature
Addition of glucose
Which statement best describes the role of the gamma subunit in ATP synthase?
It rotates relative to the surrounding subunits.
It binds ATP directly.
It forms the channel for proton movement.
It synthesizes ATP.
In the "Binding Change Mechanism" model, what determines the conformation of the catalytic site of the beta subunit?
Its contact with the gamma subunit
The number of protons present
The presence of ATP
The shape of the F0 base
Which of the following is NOT a state that the binding sites on the catalytic subunit can be in?
Open (O)
Loose (L)
Tight (T)
Closed (C)
Why is the "Binding Change Mechanism" model of ATP production supported?
There is structural and experimental evidence.
It is the only possible explanation.
It was proposed by a Nobel laureate.
It does not require any subunits.
How is ATP synthesized in the "Binding Change Mechanism" model?
Through rotational catalysis while the stalk of ATP synthase rotates relative to the head.
By direct transfer of phosphate from F0 to F1.
By diffusion of ATP through the membrane.
By chemical reaction in the cytoplasm.
Where do the H+ ions accumulate as a result of the electron transport chain (ETC)?
Intermembrane space
Matrix
I really don’t know
Cytoplasm
What is the role of the c ring in the F₀ subunit of ATP synthase?
It binds ATP directly.
It forms a base for proton diffusion and rotation.
It synthesizes glucose.
It transports electrons.
How does the rotation of the c ring contribute to ATP synthesis?
It breaks down ATP.
It provides twisting force that drives ATP synthesis.
It releases oxygen.
It absorbs light energy.
Describe the experimental demonstration of rotation in ATP synthase using a labeled actin filament.
The actin filament remains stationary.
The actin filament rotates when ATP is present, powered by ATP hydrolysis.
The actin filament glows but does not move.
The actin filament breaks apart.
Which direction is the ATP synthase pointing?
F₀ base opens to Intermembrane space
F₀ base opens to Matrix
I really don’t know
F₀ base opens to cytoplasm
Where does the ATP end up?
in Intermembrane space
in Matrix
in cytoplasm
in nucleus
What does the H⁺ gradient drive in mitochondria?
Transport of ADP into and ATP out of the mitochondrion
Synthesis of glucose from pyruvate
Movement of DNA into the nucleus
Export of oxygen from the cell
Which factor is most important in controlling the rate of respiration in mitochondria?
ADP
Oxygen
Glucose
Pyruvate
Other factors influence the rate of respiration, but what is true about these pathways?
The pathways are poorly understood
The pathways are well understood
The pathways do not exist
The pathways only occur in plants
