Biology 6, 7, 8
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.
ER
All eukaryotic cells contain at least one Golgi complex, typically located in the cytoplasm and near the endoplasmic reticulum. Which of the following best describes a process that occurs within the Golgi complex? A) Enzymatic modification of newly synthesized integral membrane proteins B) Synthesis of cytosolic proteins based on the nucleotide sequences of mRNAs C) Degradation of proteins by hydrolytic enzymes contained within the complex D) Synthesis of various types of lipids
Enzymatic modification of newly synthesized integral membrane proteins
Which of the following statements regarding enzymes is true? A) Enzymes decrease the free energy change of a reaction. B) Enzymes increase the rate of a reaction. C) Enzymes change the direction of chemical reactions. D) Enzymes are permanently altered by the reactions they catalyze. E) Enzymes prevent changes in substrate concentrations.
Enzymes increase the rate of a reaction
Which of the following claims is scientifically accurate and consistent with an observation that a decrease in lysosome production within a cell leads to a decline in mitochondrial activity? A) A lack of lysosomes will cause a decrease in the synthesis of enzymes necessary for cellular respiration. B) Fewer lysosomes will be available to break down macromolecules to provide the necessary nutrients for cellular respiration. C) Fewer lysosomes will be available to store materials required for the functioning of the mitochondria. D) Lysosomes will not be available to modify proteins so that they are targeted to the mitochondria.
Fewer lysosomes will be available to break down macromolecules to provide the necessary nutrients for cellular respiration
Liver cells manufacture glycoproteins, while adipose cells store fat. Which of the following subcellular structures is likely to be more prominent in liver cells than in adipose cells? A) Nucleus B) Golgi apparatus C) Cytoskeleton D) Plasma membrane
Golgi Apparatus
Which of the following are capable of converting light energy to chemical energy? A) chloroplasts B) mitochondria C) leucoplasts D) peroxisomes E) Golgi bodies
chloroplasts
Which of the following contain the 9 + 2 arrangement of microtubules? A) cilia B) centrioles C) flagella D) A and C only E) A, B, and C
cilia and flagella
Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n) A) competitive inhibitor of the enzyme. B) noncompetitive inhibitor of the enzyme. C) allosteric activator of the enzyme. D) cofactor necessary for enzyme activity. E) coenzyme derived from a vitamin
cofactor necessary for enzyme activity.
In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which of the following organelles functions in this compartmentalization? A) chloroplast B) lysosome C) central vacuole D) peroxisome E) glyoxysome
lysosome
recycle cells organic material
lysosome
What are the membrane structures that function in active transport? A) peripheral proteins B) carbohydrates C) cholesterol D) cytoskeleton filaments E) integral proteins
integral proteins
The active site of an enzyme is the region that A) binds allosteric regulators of the enzyme. B) is involved in the catalytic reaction of the enzyme. C) binds the products of the catalytic reaction. D) is inhibited by the presence of a coenzyme or a cofactor. E) both A and B
is involved in the catalytic reaction of the enzyme.
Water passes quickly through cell membranes because A) the bilayer is hydrophilic. B) it moves through hydrophobic channels. C) water movement is tied to ATP hydrolysis. D) it is a small, polar, charged molecule. E) it moves through aquaporins in the membrane.
it moves through aquaporins in the membrane.
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 NOT be a factor that determines whether the molecule enters the cell? A) size of the drug molecule B) polarity of the drug molecule C) 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
lipid composition of the target cells' plasma membrane
A. lysosome B. vacuole C. mitochondrion D. Golgi apparatus E. peroxisome contains hydrolytic enzymes
lysosome
Which of the following pairs is mismatched? A) nucleolus-ribosomal RNA B) nucleus-DNA replication C) lysosome-protein synthesis D) cell membrane-lipid bilayer E) cytoskeleton-microtubules
lysosome-protein sysnthesis
Contains hydrolytic enzymes associated with the intracellular digestion of macromolecules A) centriole B) lysosome C) nucleolus D) peroxisome E) ribosome
lysosomes
Which of the following cell components is not directly involved in synthesis or secretion? A) ribosome B) rough endoplasmic reticulum C) Golgi body D) smooth endoplasmic reticulum E) lysosome
lysosomes
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
sER
What kinds of molecules pass through a cell membrane most easily? A) large and hydrophobic B) small and hydrophobic C) large polar D) ionic E) monosaccharides such as glucose
small and hydrophobic
How many electron pairs does carbon share in order to complete its valence shell? A) 1 B) 2 C) 3 D) 4 E) 8
4
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.
A plant or an animal
Of the following, what do both mitochondria and chloroplasts have in common? A) ATP is produced. B) DNA is present. C) Ribosomes are present. D) B and C only E) A, B, and C are correct.
ATP is produced, DNA is present, Ribosomes are present
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.
All the above
Mitochondria are found in most eukaryotic cells and contain their own DNA and ribosomes that are similar to those typical of many prokaryotic cells. Which of the following statements is justified by these observations? A) The mitochondrion is the only location in which eukaryotic cells can synthesize ATP. B) An ancestral cell most likely engulfed anaerobic prokaryote in a relationship that proved beneficial for both cells. C) Mitochondrial membranes provide abundant surface area for reactions because of the infoldings called cristae. D) The mitochondrion plays a role in respiration, but it also stores the cell's extra mRNA.
An ancestral cell most likely engulfed anaerobic prokaryote in a relationship that proved beneficial for both cells.
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? A) CO2 B) an amino acid C) glucose D) K+ E) starch
CO2
The illustration shows the active transport of hydrogen ions through a membrane protein. Which of the following best predicts the effect of not having ATP available to supply energy to this process? A) H+ ions will stop moving through the protein. B) H+ ions will move in the other direction through the protein. C) H+ ions will continue to move through the protein in the original direction but at a slower rate. D) H+ ions will begin to move through the phospholipid portion of the membrane in the original direction.
H+ ions will not stop moving through the protein
Plant cell walls are composed of cellulose, while fungal cell walls are composed of chitin. A group of scientists hypothesize that this difference means the cell wall has largely different functions in plant cells and fungal cells. Alternatively, another group of scientists hypothesize that despite their biochemical differences, plant and fungal cell walls serve similar functions. Which of the following observations would best support the alternative hypothesis described above? A) Plant cell walls are found just outside the plasma membrane, while fungal cell walls are found just beneath the plasma membrane. B) In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane. C) Some plant cells have secondary cell walls that confer additional rigidity, while fungal cells do not. D) Photosynthesis occurs in plant cells, but it does not occur in fungal cells.
In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane
Which of the following statements is correct about diffusion? A) It is very rapid over long distances. B) It requires an expenditure of energy by the cell. C) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. D) It is an active process in which molecules move from a region of lower concentration to one of higher concentration. E) It requires integral proteins in the cell membrane.
It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
Why is ATP an important molecule in metabolism? A) Its hydrolysis provides an input of free energy for exergonic reactions. B) It provides energy coupling between exergonic and endergonic reactions. C) Its terminal phosphate group contains a strong covalent bond that when hydrolyzed releases free energy. D) A and B only E) A, B and C
It provides energy coupling between exergonic and endergonic reactions.
Which of the following statements about metabolism is incorrect? A) Metabolism is an emergent property of life at the level of organisms. B) Metabolism manages the utilization of materials and energy resources. C) The uptake of water associated with the hydrolysis of biological polymers is part of metabolism. D) Metabolism depends on a constant supply of energy. E) None of these statements about metabolism is incorrect.
Metabolism is an emergent property of life at the level of organisms.
Which of the following is the strongest evidence supporting the endosymbiont hypothesis? A) Mitochondria have their own DNA and divide independently of the cell. B) Mitochondria can carry out hydrolytic reactions on organic molecules. C) Mitochondria have a highly folded membrane. D) Mitochondria are found in both plants and animals
Mitochondria have their own DNA and divide independently of the cell.
A. lysosome B. vacuole C. mitochondrion D. Golgi apparatus E. peroxisome contains its own DNA and ribosomes
Mitochondrion
A. lysosome B. vacuole C. mitochondrion D. Golgi apparatus E. peroxisome one of the main energy transformers of cells
Mitochondrion
Which of the following statements best explains the processes of passive and active transport? A) Passive transport is the net movement of substances down a concentration gradient that requires metabolic energy. Active transport is the movement of substances up a concentration gradient that does not require energy. B) Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy. C) Passive transport is the net movement of substances up a concentration gradient that requires metabolic energy. Active transport is the movement of substances down a concentration gradient that does not require metabolic energy. D) Passive transport is the net movement of substances up a concentration gradient that does not require metabolic energy. Active transport is the movement of substances down a concentration gradient that requires energy.
Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy
A. a feature of all cells B. found in prokaryotic cells only C. found in eukaryotic cells only D. found in plant cells only E. found in animal cells only nucleoid A. B. C. D. E.
Prokaryotic cells
Which of the following is most similar in structure to ATP? A) an anabolic steroid B) a DNA helix C) RNA nucleotides D) an amino acid with three phosphate groups attached E) a phospholipid
RNA nucleotides
Which of the following functional differences between the rough and smooth endoplasmic reticulum (ER) is explained by the structural differences between them? A) Rough ER breaks down toxic substances, and smooth ER only transports them out of the cell. B) Rough ER can synthesize and package lipids for export, and smooth ER cannot. C) Rough ER can produce ATP , and smooth ER cannot. D) Rough ER can synthesize and package proteins for export, and smooth ER cannot
Rough ER can synthesize and package proteins for export, and smooth ER cannot
Carbon dioxide most likely enters a cell through which of the following processes? A) Simple diffusion through the membrane B) Facilitated diffusion through membrane proteins C) Active transport through membrane proteins D) Active transport through aquaporins
Simple diffusion through the membrane
Which of the following statements best supports the claim that certain organelles within eukaryotic cells evolved from free-living prokaryotic cells? A) The cytoplasm of both eukaryotes and prokaryotes is surrounded by a plasma membrane. B) Eukaryotes and prokaryotes both contain ribosomes, but the ribosomes of eukaryotes are more complex in structure than those of prokaryotes. C) Eukaryotes exchange segments of internal membranes between the endoplasmic reticulum and Golgi apparatus, but prokaryotes have no such internal membranes. D) Some organelles contain their own DNA that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cell's nucleus.
Some organelles contain their own DNA that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cell's nucleus.
When biologists wish to study the internal ultrastructure of cells, they most likely would use A) a light microscope. B) a scanning electron microscope. C) a transmission electronic microscope. D) A and C only E) A, B, C
T.E.M
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.
The binding of the substrate changes the shape of the enzyme's active site.
Intravenous (IV) solutions administered to patients are normally isotonic. Which of the following is most likely if an IV of distilled water is administered to a patient? A) The cells that are exposed to hypotonic solutions will shrink as a result of salt moving into the blood. B) The liver will secrete additional bile salts into the blood to raise the tonicity of the administered fluid. C) The cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood. D) The patient's respiration rate will slow to compensate for the higher levels of circulating blood.
The cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood.
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 a kink in the fatty acid tail, forcing adjacent lipids to be further apart. B) Unsaturated fatty acids have a higher cholesterol content. 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 a shorter fatty acid tail.
The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be further apart.
A team of biologists develop a new drug, and one team member hypothesizes that the drug is incapable of freely passing across the plasma membrane and requires the help of membrane proteins to enter cells. Alternatively, another biologist on the team hypothesizes that the drug can diffuse passively across the plasma membrane like O2 and CO2 can. Which of the following, if true about the drug, best supports the alternative hypothesis that the new drug will exhibit simple diffusion across plasma membranes? A) The drug is a small nonpolar molecule. B) The drug is a small charged molecule. C) The drug is a large polar molecule. D) The drug is a large charged molecule.
The drug is a small nonpolar molecule
Which of the following comparisons between prokaryotic and eukaryotic cells is incorrect? A) The lack of organelles in prokaryotes means that they are structurally less complex than eukaryotes. B) The lack of internal membranes means that prokaryotes cannot compartmentalize function to the same extent as eukaryotes. C) All membrane function in prokaryotes is accomplished in the plasma membrane, while in eukaryotes, these functions are more distributed among the organelles. D) The specialization of function in organelles suggests that eukaryotes will contain a wider variety of phospholipids than prokaryotes. E) The lack of organelles in prokaryotes means that the basic cellular functions are different in prokaryotes than in eukaryotes.
The lack of organelles in prokaryotes means that the basic cellular functions are different in prokaryotes than in eukaryotes.
What is the reason why hydrocarbons are not soluble in water? A) The majority of their bonds are polar covalent carbon to hydrogen linkages. B) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. C) They are hydrophilic. D) They exhibit considerable molecular complexity and diversity. E) They are lighter than water.
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
The first law of thermodynamics states that energy can be neither created nor destroyed. For living organisms, which of the following is an important consequence of the first law? A) The energy content of an organism is constant. B) The organism ultimately must obtain all of the necessary energy for life from its environment. C) The entropy of an organism decreases with time as the organism grows in complexity. D) Organisms are unable to transform energy. E) Life does not obey the first law of thermodynamics.
The organism ultimately must obtain all of the necessary energy for life from its environment.
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.
The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells.
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 free energy change of the reaction is the same as the reaction in the absence of the enzyme. C) The reaction always goes in the direction toward chemical equilibrium. D) A and B only E) A, B, and C
The reaction is faster than the same reaction in the absence of the enzyme.
Which of the following is true for all exergonic reactions? A) The products have more total energy than the reactants. B) The reaction proceeds with a net release of free energy. C) Some reactants will be converted to products. D) A net input of energy from the surroundings is required for the reactions to proceed. E) The reactions are nonspontaneous.
The reaction proceeds with a net release of free energy.
A scientist designed an experiment to test an artificial membrane that mimics the phospholipid bilayer of a cell. The scientist built a tube that was divided by an artificial membrane and filled with distilled water. The scientist put a known amount of a protein into the water on one side of the membrane. After some time, the scientist measured the concentration of the protein on either side of the membrane but found that there had been no change. Which of the following experimental changes would allow the scientist to observe transport of a solute across the artificial membrane? A) Increase the solute concentration in the solution B) Use a small, nonpolar solute instead of a protein C) Increase the temperature of the solution D) Add artificial aquaporins to the membrane
Use a small, nonpolar solute instead of a protein
Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes? A) facilitated diffusion of molecules down their concentration gradients B) active transport of molecules against their concentration gradients C) maintaining the integrity of a fluid mosaic membrane D) maintaining membrane fluidity at low temperatures E) a cell's ability to distinguish one type of neighboring cell from another
a cell's ability to distinguish one type of neighboring cell from another
Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. What is substance X? A) a coenzyme B) an allosteric inhibitor C) a substrate D) an intermediate E) the product
a substrate
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's A) entropy. B) activation energy. C) endothermic level. D) heat content. E) free-energy content
activation energy
The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is A) diffusion. B) active transport. C) osmosis. D) facilitated diffusion. E) exocytosis.
active transport
How can one increase the rate of a chemical reaction? A) Increase the activation energy needed. B) Cool the reactants. C) Decrease the concentration of the reactants. D) Add a catalyst. E) Increase the entropy of the reactants.
add a catalyst
Microfilaments are well known for their role in which of the following? A) ameboid movement B) formation of cleavage furrows C) contracting of muscle cells D) A and B only E) A, B, and C
ameboid movement, formation of cleavage furrows, contracting muscle cells
The surface of an integral membrane protein would be best described as A) hydrophilic. B) hydrophobic. C) amphipathic. D) completely covered with phospholipids. E) exposed on only one surface of the membrane.
amphipathic
Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. Substance A functions as A) a coenzyme. B) an allosteric inhibitor. C) the substrate. D) an intermediate. E) a competitive inhibitor.
an allosteric inhibitor.
Which of the following are prokaryotic cells? A) plants B) fungi C) bacteria D) animals E) B and C only
bacteria
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
breaking the bond between glucose and fructose and forming new bonds from the atoms of water.
All of the following structures and proteins are directly associated with movement in cells or by cells except A) cilia. B) dynein. C) actin. D) flagella. E) centrosomes.
centrosomes
Grana, thylakoids, and stroma are all components found in A) vacuoles. B) chloroplasts. C) mitochondria. D) lysosomes. E) nuclei.
chloroplasts
The sodium-potassium pump is called an electrogenic pump because it A) pumps equal quantities of Na+ and K+ across the membrane. B) pumps hydrogen ions out of the cell. C) contributes to the membrane potential. D) ionizes sodium and potassium atoms. E) is used to drive the transport of other molecules against a concentration gradient.
contributes to membrane potential
ATP generally energizes a cellular process by A) releasing heat upon hydrolysis. B) acting as a catalyst. C) coupling free energy released by ATP hydrolysis to free energy needed by other reactions. D) breaking a high-energy bond. E) binding directly to the substrate(s) of the enzyme.
coupling free energy released by ATP hydrolysis to free energy needed by other reactions.
What type(s) of bond(s) does carbon have a tendency to form? A) ionic B) hydrogen C) covalent D) A and B only E) A, B, and C
covalent
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
dehydration reactions
Ions diffuse across membranes down their A) chemical gradients. B) concentration gradients. C) electrical gradients. D) electrochemical gradients. E) A and B are correct.
electrochemical gradients
The presence of cholesterol in the plasma membranes of some animals A) enables the membrane to stay fluid more easily when cell temperature drops. B) enables the animal to remove hydrogen atoms from saturated phospholipids. C) enables the animal to add hydrogen atoms to unsaturated phospholipids. D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell. E) makes the animal more susceptible to circulatory disorders
enables the membrane to stay fluid more easily when cell temperature drops.
A chemical reaction that has a positive G is correctly described as A) endergonic. B) endothermic. C) enthalpic. D) spontaneous. E) exothermic
endergonic
All of the following processes take material into cells except A) pinocytosis. B) endocytosis. C) exocytosis. D) active transport. E) carrier-facilitated diffusion.
exocytosis
A. feature of all cells B. found in prokaryotic cells only C. found in eukaryotic cells only D. found in plant cells only E. found in animal cells only plasma membrane A. B. C. D. E.
feature of all cells
Which of the following adheres to the extracellular surface of animal cell plasma membranes? A) fibers of the extracellular matrix B) fibers of the cytoskeleton C) the phospholipid bilayer D) cholesterol E) carrier proteins
fibers from extracellular matrix
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? A) peroxisomes B) desmosomes C) gap junctions D) extracellular matrix E) tight junctions
gap junctions
A. lysosome B. vacuole C. mitochondrion D. Golgi apparatus E. peroxisome produces and modifies polysaccharides that will be secreted
golgi apparatus
Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are A) hypotonic to both fresh water and the salt solution. B) hypertonic to both fresh water and the salt solution. C) hypertonic to fresh water but hypotonic to the salt solution. D) hypotonic to fresh water but hypertonic to the salt solution. E) isotonic with fresh water but hypotonic to the salt solution.
hypertonic to fresh water but hypotonic to the salt solution.
All of the following molecules are part of the cell membrane except A) lipids. B) nucleic acids. C) proteins. D) phosphate groups. E) steroids.
nucleic acids
An organism with a cell wall would have the most difficulty doing which process? A) diffusion B) osmosis C) active transport D) phagocytosis E) exocytosis
phagocytosis
Which of the following types of molecules are the major structural components of the cell membrane? A) phospholipids and cellulose B) nucleic acids and proteins C) phospholipids and proteins D) proteins and cellulose E) glycoproteins and cholesterol
phosphoholipids + proteins
The difference between pinocytosis and receptor-mediated endocytosis is that A) pinocytosis brings only water into the cell, but receptor-mediated endocytosis brings in other molecules as well. B) pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area. C) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. D) pinocytosis requires cellular energy, but receptor-mediated endocytosis does not. E) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.
pinocytosis brings only water into the cell, but receptor-mediated endocytosis brings in other molecules as well.
All of the following are functions of integral membrane proteins except A) protein synthesis. B) active transport. C) hormone reception. D) cell adhesion. E) cytoskeleton attachment
protein sysnthesis
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? A) lipids B) starches C) proteins D) steroids E) glucose
proteins
Which structure is the site of the synthesis of proteins that may be exported from the cell? A) rough ER B) lysosomes C) plasmodesmata D) Golgi vesicles E) tight junctions
rER
Of the following, which is probably the most common route for membrane flow in the endomembrane system? A) Golgi - lysosome - ER - plasma membrane B) nuclear envelope - lysosome - golgi - plasma membrane C) rER - vesicles - golgi - plasma membrane D) ER - chloroplasts - mitochondrion - cell membrane
rER - vesicles - golgi - plasma membrane
Which of the following compounds require the presence of the nuclear pores to move between the cytoplasm and the interior of the nucleus? A) ribosomal RNA B) messenger RNA C) proteins synthesized in the cytoplasm that are part of ribosomes D) A and B only E) A, B, and C
ribosomal RNA, messenger RNA, proteins synthesized in the cytoplasm that are part of ribosomes (E)
Which of the following forms of energy is least available to accomplish cellular work? A) light energy B) electrical energy C) thermal energy (heat) D) mechanical energy E) potential energy
thermal energy (heat)
