Chapter 4-5 Quizzes

Which molecule from glycolysis or the citric acid pathway serves as the building block for lipid synthesis? 1) Acetyl CoA 2) Pyruvate 3) α-Ketoglutarate 4) Oxaloacetate 5) Glucose

1) Acetyl CoA

When purified cytochrome oxidase is exposed to cyanide, the cyanide binds reversibly and with high affinity to the enzyme's active site. What will be the likely outcome if mitochondria are exposed to high levels of cyanide? 1) The cyanide will prevent movement of electrons along the electron transport chain. 2) The cyanide will prevent oxygen from reaching the mitochondrial matrix. 3) The cyanide will block movement of protons across the inner mitochondrial membrane. 4) The cyanide will inhibit transfer of electrons from NADH to initiate electron transport.

1) The cyanide will prevent movement of electrons along the electron transport chain.

How many layers make up the typical cell membrane? 1) Two 2) It varies all the time. 3) Three 4) Four 5) One

1) Two

Ribosomes are not found in or associated with 1) the Golgi apparatus. 2) chloroplasts. 3) the rough endoplasmic reticulum. 4) prokaryotic cells. 5) mitochondria.

1) the Golgi apparatus.

The existence of a concentration gradient of glucose across a membrane means that 1) the glucose molecules are more crowded on one side of the membrane than on the other. 2) there are more glucose molecules within the bilayer of the membrane than outside of the membrane. 3) the glucose molecules are chemically bonded more tightly on one side of the membrane than on the other. 4) there is a high concentration of water on both sides of the membrane. 5) there is a high concentration of glucose on both sides of the membrane.

1) the glucose molecules are more crowded on one side of the membrane than on the other.

Which molecule functions as a recognition site for interactions between cells? 1) Cholesterol 2) Glycolipid 3) Fatty acid 4) RNA 5) Phospholipid

2) Glycolipid

How is free energy that is captured in the molecules NADH and FADH2 passed on in the cell? 1) It is used to reduce oxygen. 2) It is used to establish a proton gradient across a membrane. 3) It is used to phosphorylate ADP via substrate-level phosphorylation. 4) It is used to drive the citric acid cycle. 5) It is used to oxidize another round of glucose molecules.

2) It is used to establish a proton gradient across a membrane.

Why is oxygen important in the electron transport pathway and ATP synthesis? 1) Oxygen donates electrons to the electron transport chain, initiating the electron transport process. 2) Oxygen accepts electrons at the end of the electron transport chain to free the pathway for a new set of electrons. 3) Oxygen is needed to drive the formation of ATP by ATP synthase. 4) Oxygen combines with hydrogen to produce water, a molecule that is essential for life.

2) Oxygen accepts electrons at the end of the electron transport chain to free the pathway for a new set of electrons.

A student discussing the role of the Golgi apparatus in cells makes the following three statements: • A variety of proteins enter the Golgi from vesicles that pinch off from the rough ER. • Within the Golgi apparatus, different proteins are modified by the activities of sugar molecules. • After modification, the proteins move within vesicles to specific locations in the cell. Evaluate the accuracy of the student's statements. 1) The second and third statements are accurate; the first statement is not accurate. 2) The first and third statements are accurate; the second statement is not accurate. 3) Only the first statement is accurate. 4) Each is an accurate statement.

2) The first and third statements are accurate; the second statement is not accurate.

Catabolic interconversion is a metabolic pathway in which 1) a citric acid intermediate is a starting point. 2) a large molecule is broken down into its constituent molecules and releases energy. 3) many small molecules are combined into larger molecules and a pathway that requires energy. 4) large molecules are built up into even larger molecules and a pathway that requires energy. 5) small molecules are broken down into CO2 and water molecules and release energy.

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

Plants are green because 1) plants do not possess green pigment. 2) chlorophylls absorb blue and red light and reflect green light. 3) plants do not possess red or blue pigments. 4) energized chlorophyll a emits green light. 5) chlorophylls absorb green light.

2) chlorophylls absorb blue and red light and reflect green light.

Ribosomes are 1) absent in some cells. 2) composed of protein and nucleic acid components. 3) sites of transcription. 4) membrane-enclosed compartments. 5) analogous to power plants.

2) composed of protein and nucleic acid components.

Phagocytosis refers to 1) the specific import of small molecules. 2) engulfing of particles by a cell. 3) the export of macromolecules. 4) the nonspecific intake of fluids by the cell. 5) the delivery of receptor proteins to specific locations within the cell.

2) engulfing of particles by a cell.

Triglycerides are major energy storage molecules. Which statement about the complete oxidation of triglycerides to CO2 and water and the oxidation of glucose to CO2 and water is true? 1) ATP is hydrolyzed at some point in both pathways. 2) Both generate the same ratio of moles of ATP per mole of fuel molecule oxidized. 3) Both the complete oxidation of triglycerides and that of glucose use acetyl CoA as an intermediate. 4) Glucose oxidation and triglyceride oxidation use glycolysis. 5) They are both endergonic.

3) Both the complete oxidation of triglycerides and that of glucose use acetyl CoA as an intermediate.

_______ proteins are embedded in biological membranes, whereas _______ proteins are associated with surface regions of biological membranes. 1) Transmembrane; integral 2) Peripheral; extracellular 3) Integral; peripheral 4) Cytoskeletal; integral 5) Extracellular; peripheral

3) Integral; peripheral

Which structure(s) is/are directly involved in the movement of organelles within a cell? 1) Microfilaments 2) Intermediate filaments 3) Microtubules 4) Golgi apparatus 5) Endoplasmic reticulum

3) Microtubules

Ribosomes are made up of 1) DNA and proteins. 2) proteins only. 3) RNA and proteins. 4) DNA and RNA. 5) DNA only.

3) RNA and proteins.

A cell that always lacks a cell wall is the _______ cell. 1) prokaryotic 2) plant 3) animal 4) bacterial 5) fungal

3) animal

The cell membrane is said to _______ as it folds inward to form a pocket around materials in the environment during phagocytosis, pinocytosis, and receptor-mediated endocytosis. 1) contract 2) expand 3) invaginate 4) melt 5) self-assemble

3) invaginate

The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are 1) peripheral membrane proteins. 2) integral membrane proteins. 3) lipids. 4) carbohydrates. 5) nucleic acids.

3) lipids.

he membrane components that enable a biological membrane to have fluidity are 1) integral membrane proteins. 2) peripheral membrane proteins. 3) lipids. 4) carbohydrates. 5) oligosaccharides.

3) lipids.

The DNA in a prokaryotic cell can be found in the region called the 1) carboxysome. 2) metabolome. 3) nucleoid. 4) nucleus. 5) ribosome.

3) nucleoid.

The fluid mosaic model of natural membrane structure describes a phospholipid bilayer in which 1) proteins may readily flip to the other layer. 2) All the other answer choices are correct. 3) proteins may move about within the plane of the membrane. 4) lipids may readily flip to the other layer.

3) proteins may move about within the plane of the membrane.

The chemiosmotic generation of ATP is driven by 1) osmotic movement of water into an area of high solute concentration. 2) the addition of protons to ADP and phosphate via enzymes. 3) the proton-motive force. 4) oxidative phosphorylation. 5) isocitrate dehydrogenase.

3) the proton-motive force.

The conversion of A to B, which is an endergonic reaction, can proceed if it is coupled 1) to an anabolic reaction. 2) to another endergonic reaction. 3) with the hydrolysis of ATP. 4) with a reaction that requires energy. 5) with the condensation of Pi and ADP.

3) with the hydrolysis of ATP.

In a reaction catalyzed by the enzyme rubisco, CO2 combines with a _______ molecule (ribulose 1,5-bisphosphate) to form two molecules of a _______ molecule (3-phosphoglycerate). 1) 6-carbon; 3-carbon 2) 5-carbon; 2-carbon 3) 3-carbon; 5-carbon 4) 5-carbon; 3-carbon

4) 5-carbon; 3-carbon

Both primary and secondary active transport require energy in the form of _______ to drive substances across a cell membrane. 1) glucose 2) channel proteins 3) concentration gradients 4) ATP

4) ATP

How are ATP and NADH similar? 1) Both molecules are oxidized by molecular oxygen (O2) in reactions that release energy for use by the cell. 2) The same quantity of free energy is released per molecule of ATP or NADH. 3) Both ATP and NADH function as reducing agents in metabolic reactions. 4) Both compounds function as mobile energy carrier molecules in a cell. 5) They are interchangeable energy carriers, allowing the cell to use whichever molecule is in greatest abundance as a source of energy.

4) Both compounds function as mobile energy carrier molecules in a cell.

Besides the proteins being processed for distribution, what other components could be expected to be found inside the Golgi apparatus? 1) DNA 2) Ribosomes 3) Cytoskeleton 4) Enzymes

4) Enzymes

Which statement would be true of a membrane-bound protein that works in conjunction with a sodium-potassium pump during secondary active transport? 1) It will be able to transport an ion in both directions across the cell membrane and a small molecule in one direction. 2) It will move a small molecule across the cell membrane in response to a build-up in concentration of the molecule in the external environment. 3) It will block a small molecule from moving across the cell membrane in response to an increase in concentration of an ion in the external environment. 4) Its conformation will change when both an ion and a small molecule bind to it.

4) Its conformation will change when both an ion and a small molecule bind to it.

Which of the following accurately describes the relative sizes of cytoskeletal elements? 1) Intermediate filaments > microtubules > microfilaments 2) Microtubules > microfilaments > intermediate filaments 3) Microfilaments > intermediate filaments > microtubules 4) Microtubules > intermediate filaments > microfilaments 5) Intermediate filaments > microfilaments > microtubules

4) Microtubules > intermediate filaments > microfilaments

Which is most directly derived from intermediates in the citric acid cycle? 1) Triglycerides 2) Fatty acids 3) Starch 4) Pyrimidines 5) Glycerol

4) Pyrimidines

Water moves across a cell membrane through a channel protein, whereas glucose moves across a cell membrane via a carrier protein. Which statement provides a valid comparison of these two membrane transport systems? 1) Genetic mutations can alter glucose transport into a cell but cannot alter water transport. 2) A cell can add more sites for water transport to increase water movement across the membrane but cannot achieve the same result for glucose using a similar strategy. 3) Glucose moves in a direction from high to low concentration, while water moves in a direction that is not governed by differing solute concentrations. 4) Several water molecules move one after the other through the opening provided by a channel protein, while glucose is transported across the membrane via a carrier protein one molecule at a time. 5) Water transport occurs without the cell using energy, whereas glucose transport requires energy input by the cell.

4) Several water molecules move one after the other through the opening provided by a channel protein, while glucose is transported across the membrane via a carrier protein one molecule at a time.

Which statement about ATP is true? 1) The phosphate-bond energy of ATP is used to power catabolic metabolism. 2) The synthesis of ATP is an energy-neutral reaction. 3) The phosphate-bond energy of ATP may be transformed into the energy in a magnetic field. 4) The hydrolysis of ATP to ADP and Pi is an exergonic reaction. 5) ATP is a building block of protein.

4) The hydrolysis of ATP to ADP and Pi is an exergonic reaction.

When a photon is absorbed by chlorophyll, 1) hydrogen ions are released. 2) the chlorophyll molecules fluoresce. 3) ATP is split into ADP, phosphate, and energy. 4) the chlorophyll becomes "excited," or energized. 5) a greater number of light wavelengths can be absorbed.

4) the chlorophyll becomes "excited," or energized.

If a cell has an increased need for a particular molecule already present in a higher concentration within the cell than in the extracellular fluid, the cell might 1) use passive transport, which moves molecules in a direction opposite to the one in which active transport moves them. 2) use passive transport, which moves molecules in a direction that tends to bring about equilibrium. 3) use active transport, which moves molecules in the same direction as diffusion moves them. 4) use active transport, which moves molecules in a direction opposite to the one in which diffusion moves them. 5) use facilitated diffusion, which involves membrane proteins that assist with moving molecules across the cell membrane.

4) use active transport, which moves molecules in a direction opposite to the one in which diffusion moves them.

Microfilaments can be involved in contractions that change the shape of a cell when they are 1) being assembled from actin monomers. 2) complexed with intermediate filaments to form desmosomes. 3) working with microtubules to bend cilia and flagella. 4) associated with actin-associated proteins that are adding actin monomers to the "plus end" of the filament. 5) associated with motor proteins such as myosin.

5) associated with motor proteins such as myosin.

Receptor-mediated endocytosis 1) is also known as "cellular drinking." 2) is nonspecific. 3) is a form of phagocytosis. 4) directly involves the Golgi apparatus. 5) results in the formation of clathrin-coated vesicles.

5) results in the formation of clathrin-coated vesicles.