BIO FINAL

Which component in the accompanying figure is a protein fiber of the extracellular matrix? A) A B) B C) C D) E

A

Which is not a polymer? A) Glucose B) Starch C) RNA D) DNA

A) Glucose

__ When nucleotides polymerize to form a nucleic acid, ________. A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second B) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second C) covalent bonds form between the bases of two nucleotides D) hydrogen bonds form between the bases of two nucleotides

A). A covalent bond forms between the sugar of one nucleotide and the phosphate of a second.

__ In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules? A) ATP, CO2, and ethanol (ethyl alcohol) B) ATP, CO2, and lactate C) ATP, NADH, and ethanol D) ATP, CO2, and acetyl CoA

A). ATP, CO2, and ethanol (ethyl alcohol)

__ Which of the following types of reactions would decrease the entropy within a cell? A) anabolic reactions B) hydrolysis C) digestion D) catabolic reactions

A). Anabolic reactions

__ A decrease in entropy is associated with which type of reaction? A) dehydration B) catabolic C) depolymerization D) hydrolysis

A). Dehydration

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart. B) Dehydration reactions eliminate water from membranes; hydrolysis reactions add water to membranes. C) Dehydration reactions and hydrolysis reactions assemble polymers from monomers. D) Hydrolysis reactions create polymers, and dehydration reactions create monomers.

A). Dehydration reactions assembles polymers; hydrolysis reactions break polymers apart.

__ A chemical reaction that has a positive ΔG is best described as ________. A) endergonic B) enthalpic C) spontaneous D) exergonic

A). Endergonic

Which of the following statements describes the first law of thermodynamics? A) Energy cannot be created or destroyed. B) The entropy of the universe is decreasing. C) The entropy of the universe is constant. D) Energy cannot be transferred or transformed.

A). Energy cannot be created or destroyed

Which of the following metabolic processes take place in the cytosol of a eukaryotic cell? A) glycolysis and fermentation B) fermentation and chemiosmosis C) oxidation of pyruvate to acetyl CoA D) citric acid cycle

A). Glycolysis and fermentation

Humans can digest starch but not cellulose because ________. A) humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose B) starch monomers are joined by covalent bonds, and cellulose monomers are joined by ionic bonds C) the monomer of starch is glucose, while the monomer of cellulose is galactose D) Starch is softer than cellulose

A). Humans have enzymes that can hydrolyze the a-glycosidic linkages of starch but not the B-glycosidic linkages of cellulose

The membranes of winter wheat are able to remain fluid when it is extremely cold by ________. A) increasing the proportion of unsaturated phospholipids in the membrane B) decreasing the percentage of cholesterol molecules in the membrane C) decreasing the number of hydrophobic proteins in the membrane D) increasing the proportion of glycolipids in the membrane

A). Increasing the proportion of unsaturated phospholipids in the membrane

Which of the following statements describes a characteristic feature of a carrier protein in a plasma membrane? A) It exhibits specificity for a particular type of molecule. B) It requires the expenditure of cellular energy to function. C) It works against diffusion. D) It has no hydrophobic regions.

A). It exhibits specificity for a particular type of molecule.

__ White blood cells engulf bacteria using ________. A) phagocytosis B) pinocytosis C) osmosis D) receptor-mediated exocytosis

A). Phagocytosis

You disrupt all hydrogen bonds in a protein. What level of structure will be preserved? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure

A). Primary structure

__ What is the function of the nuclear pore complex found in eukaryotes? A) It regulates the movement of proteins and RNAs into and out of the nucleus. B) It synthesizes the proteins required to copy DNA and make mRNA. C) It synthesizes secreted proteins. D) It assembles ribosomes from raw materials that are synthesized in the nucleus.

A). Regulates the movement of proteins and RNAs into and out of the nucleus.

__ Which of the following macromolecules enter the nucleus of a eukaryotic cell through pores in the nuclear membrane? A) ribosomal proteins B) mRNA C) rRNA D) phospholipids

A). Ribosomal protein

Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures? A) The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly. B) Unsaturated fatty acids have a higher cholesterol content, which prevents adjacent lipids from packing tightly. C) Unsaturated fatty acids are more nonpolar than saturated fatty acids. D) The double bonds block interaction among the hydrophilic head groups of the lipids.

A). The double bonds form kinks in fatty acid tails, preventing adjacent lipids from packing tightly

__ Which of the following is a major difference between RNA and DNA? A) type of sugar B) type of phosphate C) type of purines D) type of glycosidic bond

A). Type of Sugar

__ How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule? A) 10 B) 19 C) 20 D) 40

B) 19

___ Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products? A) 2 NAD+, 2 pyruvates, and 2 ATP B) 2 NADH, 2 pyruvates, and 2 ATP C) 4 NADH, 2 pyruvates, and 4 ATP D) 6 CO2, 2 pyruvates, and 2 ATP

B). 2 NADH, 2 Pyruvates, and 2ATP

___ The force driving simple diffusion is ________, while the energy source for active transport is ________. A) a concentration gradient; ADP B) a concentration gradient; ATP hydrolysis C) transmembrane pumps; an electrochemical gradient D) phosphorylated carrier proteins; ATP

B). A concentration gradient; ATP hydrolysis.

__ Which of the following statements is consistent with the second law of thermodynamics? A) A gain of free energy in a system is always associated with conversion of energy from one form to another. B) A constant input of energy is required to maintain the high level of cellular organization. C) Without an input of energy, the entropy of an organism would tend to decrease over time. D) Every energy transformation performed by an organism decreases the entropy of the universe.

B). A constant input of energy is required to maintain the high level of cellular organization.

__ A glycosidic linkage is analogous to which of the following in proteins? A) an amino group B) a peptide bond C) a disulfide bond D) a β pleated sheet

B). A peptide bond

Which of the following statements describes a central role that ATP plays in cellular metabolism? A) Hydrolysis of ATP provides an input of free energy for exergonic reactions. B) ATP provides energy coupling between exergonic and endergonic reactions. C) Hydrolysis of the terminal phosphate group stores free energy that is used for cellular work. D) Its terminal phosphate bond is stronger than most covalent bonds in other biological macromolecules

B). ATP provides energy coupling between exergonic and endergonic reactions

Which of the following molecules dramatically increases the rate of diffusion of water across cell membranes? A) the sodium-potassium pump B) aquaporins C) gated ion channels D) ATP

B). Aquaporins

Use the figures to answer the following question. Which of the groups is an acidic functional group that can dissociate and release H+ into a solution? A) A B) B C) C D) D

B). B

32) __B__ How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction? A) by binding to the active site of the enzyme, thus preventing binding of the normal substrate B) by binding to an allosteric site, thus changing the shape of the active site of the enzyme C) by decreasing the free-energy change of the reaction catalyzed by the enzyme D) by binding to the substrate, thus changing its shape so that it no longer binds to the active site of the enzyme

B). By binding to an allosteric site, thus changing the shape of the active site of the enzyme.

__ Which two functional groups are always found in amino acids? A) carbonyl and amino groups B) carboxyl and amino groups C) amino and sulfhydryl groups D) hydroxyl and carboxyl groups

B). Carboxyl and amino group

___ A characteristic 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules is associated with ________. A) bacterial flagella B) eukaryotic flagella and motile cilia C) eukaryotic flagella, motile cilia, and nonmotile cilia D) centrioles and basal bodies

B). Eukaryotic flagella and motile cilia

__ Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water ________. A) and the salt solution are both hypertonic to the cells of the celery stalks B) is hypotonic and the salt solution is hypertonic to the cells of the celery stalks C) is hypertonic and the salt solution is hypotonic to the cells of the celery stalks D) is isotonic and the salt solution is hypertonic to the cells of the celery stalks

B). Is hypotonic and the slat solution is hypertonic to the cells of the celery stalks.

Which of the following statements describes what happens to a molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction? A) It gains electrons and gains potential energy. B) It loses electrons and loses potential energy. C) It gains electrons and loses potential energy. D) It loses electrons and gains potential energy.

B). It loses electrons and loses potential energy

The voltage across a membrane is called the ________. A) chemical gradient B) membrane potential C) osmotic potential D) electrochemical gradient

B). Membrane potential

Where are the proteins of the electron transport chain located? A) mitochondrial outer membrane B) mitochondrial inner membrane C) mitochondrial intermembrane space D) mitochondrial matrix

B). Mitochondrial inner membrane

__ A sodium-potassium pump ________. A) moves three potassium ions out of a cell and two sodium ions into a cell while producing ATP for each cycle B) moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis C) moves three potassium ions out of a cell and two sodium ions into a cell using energy from ATP hydrolysis D) move three sodium ions out of a cell and two potassium ions into a cell and generates an ATP in each cycle

B). Moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis.

The citric acid cycle. If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in the accompanying figure? A) Oxaloacetate will decrease and citric acid will accumulate. B) Oxaloacetate will accumulate and citric acid will decrease. C) Both oxaloacetate and citric acid will decrease. D) Both oxaloacetate and citric acid will accumulate.

B). Oxaloacetate will accumulate and citric acid will decrease

__ Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? A) glycolysis and the oxidation of pyruvate to acetyl CoA B) oxidation of pyruvate to acetyl CoA and the citric acid cycle C) oxidative phosphorylation and fermentation D) fermentation and glycolysis

B). Oxidation of pyruvate to acetyl CoA and Citric Acid Cycle

A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound ________. A) lacks an asymmetric carbon and is probably a fat or lipid B) should dissolve in water C) should dissolve in a nonpolar solvent D) will not form hydrogen bonds with water

B). Should dissolve in water

__ Most cells cannot harness heat to perform work because ________. A) heat is not a form of energy B) temperature is usually uniform throughout a cell C) heat can never be used to do work D) heat must remain constant during work

B). Temperature is usually uniform throughout a cell

Which of the following statements 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) The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. D) A net input of energy from the surroundings is required for the reactions to proceed.

B). The reaction proceeds with a net release of free energy

__ Which of the following statements about anabolic pathways is true? A) They are usually spontaneous chemical reactions. B) They consume energy to build up polymers from monomers. C) They release energy by degrading polymers to monomers. D) They decrease the entropy of the organism and its environment.

B). They consume energy to build up polymers from monomers.

The oxygen consumed during cellular respiration is directly involved in which of the following processes or events? A) glycolysis B) accepting electrons at the end of the electron transport chain C) the citric acid cycle D) the oxidation of pyruvate to acetyl CoA

B). accepting electrons at the end of the electron transport chain

In a cytoskeleton

C) Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.

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) a noncompetitive inhibitor of the enzyme B) an allosteric activator of the enzyme C) a cofactor necessary for enzyme activity

C). A cofactor necessary for enzyme activity

__ The mathematical expression for the change in free energy of a system is ΔG = ΔH - TΔS. Which of the following statements is correct? A) ΔS is the change in enthalpy, a measure of randomness. B) ΔH is the change in entropy, the energy available to do work. C) ΔG is the change in free energy. D) T is the temperature in degrees Celsius.

C). Change in G is the change in free energy.

Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? A) membrane proteins of the inner nuclear envelope B) free ribosomes and ribosomes attached to the ER C) components of the cytoskeleton D) cellulose fibers in the cell wall

C). Components of the cytoskeleton

__ In chemiosmosis, what is the most direct source of energy that is used to convert ADP + into ATP? A) energy released as electrons flow through the electron transport chain B) energy released from substrate-level phosphorylation C) energy released from movement of protons through ATP synthase, down their electrochemical gradient D) energy released as electrons are transported across the inner mitochondrial membrane

C). Energy released from movement of protons through ATP synthase, down their electrochemical gradient

Which of the following statements about enzyme function is true? A) Enzyme function is generally increased if the three-dimensional structure or conformation of an enzyme is altered. B) Enzyme function is independent of physical and chemical environmental factors such as pH and temperature. C) Enzymes increase the rate of chemical reactions by lowering activation energy barriers. D) Enzymes increase the rate of chemical reactions by providing activation energy to the substrate.

C). Enzymes increase the rate of chemical reactions

________ is a regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme that catalyzes an early step in the pathway. A) Allosteric inhibition B) Cooperative inhibition C) Feedback inhibition D) Metabolic inhibition

C). Feedback inhibition

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

C). Golgi Apparatus

__ Which of the following statements correctly describes osmosis? A) Osmosis only takes place in red blood cells. B) Osmosis is an energy-demanding or "active" process. C) In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. D) In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration.

C). In Osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration.

__ Which of the following is a primary function of the active site of an enzyme? A) It binds allosteric regulators of the enzyme. B) It binds noncompetitive inhibitors of the enzyme. C) It catalyzes the reaction associated with the enzyme. D) It is activated by the presence of the end product of the metabolic pathway in which the enzyme is involved.

C). It catalyzes the reaction associated with the enzyme

Which of the following statements about the electron transport chain is true? A) It is driven by ATP hydrolysis. B) It includes a series of hydrolysis reactions associated with mitochondrial membranes. C) It consists of a series of redox reactions D) It occurs in the cytoplasm of both prokaryotic and eukaryotic cells.

C). It consists of a series of redox reactions

When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell? A) It is secreted as waste. B) It is used only to regenerate more ATP. C) It may be used to form a phosphorylated intermediate. D) It enters the nucleus to be incorporated in a nucleotide.

C). It may be used to form a phosphorylated intermediate

Which of the following statements is true for lipids? A) Lipids are true polymers. B) Waxes and pigments are not lipids. C) Lipids mix poorly with water. D) Lipids are true polymers and mix poorly with water.

C). Lipids mix poorly with water

__ The difference between pinocytosis and receptor-mediated endocytosis is that ________. A) pinocytosis brings only water molecules 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 can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot

C). Pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectively.

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes ________. A) dehydrogenated B) oxidized C) reduced D) redoxed

C). Reduced

Cancer cells given vinblastine would be unable to ________. A) form cleavage furrows during cell division B) migrate by amoeboid movement C) separate chromosomes during cell division D) maintain the shape of the nucleus

C). Separate chromosomes during cell division

What component of amino acid structure varies among different amino acids? A) the long carbon-hydrogen tails of the molecule B) the presence of a central C atom C) the components of the R group D) the glycerol molecule that forms the backbone of the amino acid

C). The components of the R group

__ How do phospholipids interact with water molecules? A) The polar heads avoid water; the nonpolar tails attract water (because water is polar and opposites attract). B) Phospholipids do not interact with water because water is polar and lipids are nonpolar. C) The polar heads interact with water; the nonpolar tails do not. D) Phospholipids dissolve in water.

C). The polar heads interact with water; the nonpolar tails do not.

__ Use the following figure to answer the question. The molecule illustrated in the figure ________. A) is a saturated fatty acid B) stores genetic information C) will be liquid at room temperature D) is a carbohydrate

C). Will be liquid at room temperature

___ Maltose is a disaccharide that can easily be digested into glucose molecules. The glycosidic linkage between glucose molecules in maltose is ________. A) β 1—4 B) α 1—2 C) α 1—4 D) β 1—2

C). a 1-4

__ For lipids to be fluid at room temperature, they should have ________. A) single bonds only B) a higher number of glycerol molecules C) a higher number of cis double bonds D) a longer carbon chain

C). a higher number of cis double bonds

What is a glycosidic linkage?

Covalent bonds between two Carbons.

Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules? A) acetyl-CoA B) NAD+ C) pyruvate D) NADH

D) NADH

Approximately how many molecules of ATP are produced from the complete oxidation of one molecule of glucose (C6H12O6) in aerobic cellular respiration? A) 2 B) 4 C) 18-24 D) 30-32

D). 30-32

__ Cilia and flagella bend because of ________. A) conformational changes in ATP that thrust microtubules laterally B) a motor protein called radial spokes C) contraction by myosin D) a motor protein called dynein

D). A motor protein called dynein

Which of the following statements describes a key component of the induced fit hypothesis of enzyme catalysis? A) Substrate binds to an allosteric site rather than to the active site of an enzyme. B) Binding of an activator molecule changes the shape of the active site of an enzyme. C) The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme. D) Binding of substrate to the active site changes the shape of the active site of an enzyme.

D). Binding of substrate to the active site changes the shape of the active site of an enzyme

__ During which of the following metabolic processes is most of the CO2 from the catabolism of glucose is released? A) glycolysis B) electron transport C) oxidation of pyruvate to Acetyl-CoA D) the citric acid cycle

D). Citric Acid Cycle

Which of the following conditions may be overcome by increasing the substrate concentration in an enzymatic reaction with a fixed amount of enzyme? A) the need for a coenzyme B) allosteric inhibition C) noncompetitive inhibition D) competitive inhibition

D). Competitive inhibition

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes? A) active transport B) allosteric regulation C) a reaction with a positive ΔG D) coupling of an endergonic reaction to an exergonic reaction

D). Coupling of an endergonic reaction to an exergonic reaction

__ According to the fluid mosaic model, a membrane ________. A) is composed of a fluid bilayer of phospholipids between two layers of hydrophilic proteins B) is composed of a single layer of fluid phospholipids between two layers of hydrophilic proteins C) is composed of a mosaic of fluid polysaccharides and amphipathic proteins D) is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins

D). Is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins.

Which of the following statements best describes the primary role played by oxygen in cellular respiration? A) It yields energy in the form of ATP as it is passed down the electron transport chain. B) It oxidizes glucose to form two molecules of pyruvate. C) It serves as an acceptor for carbon, forming CO2 in the citric acid cycle. D) It serves as the final acceptor for electrons from the electron transport chain.

D). It serves as the final acceptor for electrons from the electron transport chain.

__ Which of the following processes generates a proton-motive force in mitochondria? A) the flow of protons through ATP synthase down their concentration gradient B) the reduction of NAD+ by the first electron carrier in the electron transport chain C) lowering of pH in the mitochondrial matrix D) pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space

D). Pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space.

Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane? A) large hydrophobic molecules B) small hydrophobic molecules C) carbon dioxide D) small ions

D). Small Ions

Which of the following statements is true about proteins? A) Denaturation leads to bond disruption, and the molecule turns into liquid B) Denaturation is always irreversible C) Final folded structure can reveal the steps of protein folding D) Some proteins form a complete 3-D structure only when they interact with their targets

D). Some proteins form a complete 3-D structure only when they interact with their targets.

The figure shows the structures of glucose and fructose. These two molecules are ________. A) isotopes B) enantiomers C) cis-trans isomers D) structural isomers

D). Structural isomers

__ A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________. A) store large quantities of water B) import and export large quantities of protein C) actively secrete large quantities of protein D) synthesize large quantities of lipids

D). Synthesize large quantities of lipids

What is the major structural difference between starch and glycogen? A) the types of monosaccharide subunits in the molecules B) the type of glycosidic linkages in the molecule C) whether glucose is in the α or β form D) the amount of branching that occurs in the molecule

D). The amount of branching that occurs in the molecule

___ Which of the following statements is true for a system at chemical equilibrium? A) The system consumes energy at a steady rate. B) The system releases energy at a steady rate. C) The kinetic energy of the system is zero. D) The system can do no work.

D). The system can do no work

__ Saturated fats ________. A) are more common in plants than in animals B) have multiple double bonds in the carbon chains of their fatty acids C) are generally liquid at room temperature D) contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms

D). contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms.

__ What makes lipids/fats hydrophobic? A) their long carbon skeleton B) the carboxyl group at one end of the molecule C) the glycerol moiety D) presence of relatively nonpolar C—H bonds

D). presence of relatively nonpolar C-H bonds

what is the function of RNA?

Functions in the synthesis of proteins

Tay-Sachs disease has to do with

Lysosomes

What's the difference between aldose sugar and ketose sugar?

The Carbonyl group.

Enantiomers

are isomers that are mirror images of each other