Practice Questions 4-6

9) What is the purpose of using malonic acid in this experiment? A) It is a competitive inhibitor. B) It blocks the binding of fumarate. C) It is a noncompetitive inhibitor. D) It is able to bind to succinate. E) It replaces the usual enzyme.

A) It is a competitive inhibitor.

2) Which of the following types of reactions would decrease the entropy within a cell? A) dehydration reactions B) hydrolysis C) respiration D) digestion E) catabolism

A) dehydration reactions

10) Which of the following contains hydrolytic enzymes? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome

A) lysosome

18) Of the following, which cell structure would most likely be visible with a light microscope that has been manufactured to the maximum resolving power possible? A) mitochondrion B) microtubule C) ribosome D) largest microfilament E) nuclear pore

A) mitochondrion

19) An animal cell lacking glycolipids on the external surface of its plasma membrane would likely be impaired in which function? A) transporting ions against an electrochemical gradient B) cell-cell recognition C) maintaining fluidity of the phospholipid bilayer D) attaching to the cytoskeleton E) establishing the diffusion barrier to charged molecules

B) cell-cell recognition

23) Which of these are attached to the extracellular matrix? A) transmembrane proteins B) integral proteins C) peripheral proteins D) integrins E) glycoproteins

D) integrins

7-4a) Which of the following processes includes all others? A) osmosis B) diffusion of a solute across a membrane C) facilitated diffusion D) passive transport E) transport of an ion down its electrochemical gradient

D) passive transport

7-16) Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? A) The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. B) Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes. C) Unsaturated fatty acids permit more water in the interior of the membrane. D) The double bonds block interaction among the hydrophilic head groups of the lipids. E) The double bonds result in shorter fatty acid tails and thinner membranes

A) The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart.

65) An organism with a cell wall would have the most difficulty taking part in which process? A) diffusion B) osmosis C) active transport D) phagocytosis E) facilitated diffusion

D) phagocytosis

4) Which of the following statements is (are) true about enzyme-catalyzed reactions? A) The reaction is faster than the same reaction in the absence of the enzyme. B) The reaction is slower than the same reaction in the absence of the enzyme. C) The enzyme inhibits the reaction from taking place. D) A and B only E) A, B, and C

A) The reaction is faster than the same reaction in the absence of the enzyme.

7) The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that A) at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope. B) the nuclear envelope is not part of the endomembrane system. C) the nuclear envelope is physically continuous with the endoplasmic reticulum. D) small vesicles from the Golgi fuse with the nuclear envelope. E) nuclear pore complexes contain proteins.

A) at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope. OR C) the nuclear envelope is physically continuous with the endoplasmic reticulum.

3) Which of the following statements is true concerning catabolic pathways? A) They combine molecules into more energy-rich molecules. B) They are usually coupled with anabolic pathways to which they supply energy in the form of ATP. C) They are endergonic. D) They are spontaneous and do not need enzyme catalysis. E) They build up complex molecules such as protein from simpler compounds.

B) They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.

15) Grana, thylakoids, and stroma are all components found in A) vacuoles. B) chloroplasts. C) mitochondria. D) lysosomes. E) nuclei.

B) chloroplasts.

8) The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells? A) rough ER B) smooth ER C) Golgi apparatus D) Nuclear envelope E) Transport vesicles

B) smooth ER

11) Which of the following is a compartment that often takes up much of the volume of a plant cell? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome

B) vacuole

26) Cell membranes are asymmetrical. Which of the following is a most likely explanation? A) The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium. B) Cell membranes communicate signals from one organism to another. C) Cell membrane proteins are determined as the membrane is being packaged in the ER and Golgi. D) The "innerness" and "outerness" of membrane surfaces are predetermined by genes. E) Proteins can only span cell membranes if they are hydrophobic

C) Cell membrane proteins are determined as the membrane is being packaged in the ER and Golgi. OR D) The "innerness" and "outerness" of membrane surfaces are predetermined by genes.

7) According to the induced fit hypothesis of enzyme catalysis, which of the following is correct? A) The binding of the substrate depends on the shape of the active site. B) Some enzymes change their structure when activators bind to the enzyme. C) A competitive inhibitor can outcompete the substrate for the active site. D) The binding of the substrate changes the shape of the enzyme's active site. E) The active site creates a microenvironment ideal for the reaction

D) The binding of the substrate changes the shape of the enzyme's active site.

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. 8) Based on this information, which of the following is correct? A) Succinate dehydrogenase is the enzyme, and fumarate is the substrate. B) Succinate dehydrogenase is the enzyme, and malonic acid is the substrate. C) Succinate is the substrate, and fumarate is the product. D) Fumarate is the product, and malonic acid is a noncompetitive inhibitor. E) Malonic acid is the product, and fumarate is a competitive inhibitor.

C) Succinate is the substrate, and fumarate is the product.

40) A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of his veins. What will be the most probable result of this transfusion? A) It will have no unfavorable effect as long as the water is free of viruses and bacteria. B) The patient's red blood cells will shrivel up because the blood fluid is hypotonic compared to the cells. C) The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells. D) The patient's red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells. E) The patient's red blood cells will burst because the blood fluid is hypertonic compared to the cells.

C) The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells.

7-14) In order for a protein to be an integral membrane protein it would have to be which of the following? A) hydrophilic B) hydrophobic C) amphipathic D) completely covered with phospholipids E) exposed on only one surface of the membrane

C) amphipathic

5) Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in A) bringing glucose and fructose together to form sucrose. B) the release of water from sucrose as the bond between glucose and fructose is broken. C) breaking the bond between glucose and fructose and forming new bonds from the atoms of water. D) production of water from the sugar as bonds are broken between the glucose monomers. E) utilization of water as a covalent bond is formed between glucose and fructose to form sucrase.

C) breaking the bond between glucose and fructose and forming new bonds from the atoms of water.

14) What term is used to describe the transfer of energy from catabolic pathways to anabolic pathways? A) feedback regulation B) bioenergetics C) energy coupling D) entropy E) cooperativity

C) energy coupling

35) Chloride ion channels are membrane structures that include which of the following? A) gap junctions B) aquaporins C) hydrophilic proteins D) carbohydrates E) sodium ions

C) hydrophilic proteins

1) The advantage of light microscopy over electron microscopy is that A) light microscopy provides for higher magnification than electron microscopy. B) light microscopy provides for higher resolving power than electron microscopy. C) light microscopy allows one to view dynamic processes in living cells. D) A and B E) B and C

C) light microscopy allows one to view dynamic processes in living cells.

55) What is the voltage across a membrane called? A) water potential B) chemical gradient C) membrane potential D) osmotic potential E) electrochemical gradient

C) membrane potential

12) Which is one of the main energy transformers of cells? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome

C) mitochondrion

13) Which of the following contains its own DNA and ribosomes? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome

C) mitochondrion

69) In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? A) on the outside of vesicles B) on the inside surface of the cell membrane C) on the inside surface of the vesicle D) on the outer surface of the nucleus E) on the ER

C) on the inside surface of the vesicle

5) Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids? A) ribosome B) lysosome C) smooth endoplasmic reticulum D) mitochondrion E) contractile vacuole

C) smooth endoplasmic reticulum

6) A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because A) the starch solution has less free energy than the sugar solution. B) the hydrolysis of starch to sugar is endergonic. C) the activation energy barrier for this reaction cannot be surmounted without an enzyme. D) starch cannot be hydrolyzed in the presence of so much water. E) starch hydrolysis is nonspontaneous.

C) the activation energy barrier for this reaction cannot be surmounted without an enzyme.

13) Some bacteria are metabolically active in hot springs because A) they are able to maintain a cooler internal temperature. B) high temperatures make catalysis unnecessary. C) their enzymes have high optimal temperatures. D) their enzymes are completely insensitive to temperature. E) they use molecules other than proteins or RNAs as their main catalysts.

C) their enzymes have high optimal temperatures.

1) Which of the following statements is a logical consequence of the second law of thermodynamics? A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. B) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. C) Every energy transfer requires activation energy from the environment. D) Every chemical reaction must increase the total entropy of the universe. E) Energy can be transferred or transformed, but it cannot be created or destroyed.

D) Every chemical reaction must increase the total entropy of the universe.

9) Which of the following produces and modifies polysaccharides that will be secreted? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome

D) Golgi apparatus

17) A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from A) a bacterium. B) an animal, but not a plant. C) a plant, but not an animal. D) a plant or an animal. E) any kind of organism.

D) a plant or an animal.

16) Organelles other than the nucleus that contain DNA include A) ribosomes. B) mitochondria C) chloroplasts D) B and C only E) A, B, and C

D) B and C only

49) You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule enters the cell? A) blood or tissue type of the patient B) non-polarity of the drug molecule C) lack of charge on the drug molecule D) similarity of the drug molecule to other molecules transported by the target cells E) lipid composition of the target cells' plasma membrane

D) similarity of the drug molecule to other molecules transported by the target cells

4) Which of the following is a major cause of the size limits for certain types of cells? A) the evolution of larger cells after the evolution of smaller cells B) the difference in plasma membranes between prokaryotes and eukaryotes C) the evolution of eukaryotes after the evolution of prokaryotes D) the need for a surface area of sufficient area to allow the cell's function E) the observation that longer cells usually have greater cell volume

D) the need for a surface area of sufficient area to allow the cell's function

6) The Golgi apparatus has a polarity or sidedness to its structure and function. Which of the following statements correctly describes this polarity? A) Transport vesicles fuse with one side of the Golgi and leave from the opposite side. B) Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. C) Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. D) Soluble proteins in the cisternae (interior) of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. E) All of the above correctly describe polar characteristics of the Golgi function.

E) All of the above correctly describe polar characteristics of the Golgi function.

3) All of the following are part of a prokaryotic cell except A) DNA. B) a cell wall. C) a plasma membrane. D) ribosomes. E) an endoplasmic reticulum.

E) an endoplasmic reticulum.

14) Which of the following contains enzymes that transfer hydrogen from various substrates to oxygen? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome

E) peroxisome

2) A biologist is studying kidney tubules in small mammals. She wants specifically to examine the juxtaposition of different types of cells in these structures. The cells in question can be distinguished by external shape, size, and 3-dimensional characteristics. Which would be the optimum method for her study? A) transmission electron microscopy B) cell fractionation C) light microscopy using stains specific to kidney function D) light microscopy using living unstained material E) scanning electron microscopy

E) scanning electron microscopy