BIOL1009 Midterm I Sample Exam
When glucose momonmers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, enthalpy and entropy are as follows: a. +∆H, -∆S, -∆G b. +∆H, +∆S, +∆G c. -∆H, -∆S, +∆G d. +∆H, -∆S, +∆G
(not c)
Reduction of oxygen to form water occurs during a. cellular respiration only. b. photosynthesis only. c. both photosynthesis and cellular respiration. d. photorespiration only.
(not d) SOLVE
If you explore a biological concept by breaking down the complex system to its simpler components, you are using an approach called?
Reductionism
Generation of proton gradients across membranes occurs during Select one: a. both photosynthesis and cellular respiration. b. photosynthesis. c. neither photosynthesis nor cellular respiration. d. cellular respiration.
a
In alcohol fermentation, NAD+ is regenerated from NADH by a. reduction of acetaldehyde to ethanol (ethyl alcohol) b. reduction of pyruvate to form lactate. c. oxidation of ethanol to acetyl CoA. d. reduction of ethanol to pyruvate.
a
In the double helix structure of nucleic acids, cytosine hydrogen bonds to a. Guanine b. Adenine c. Deoxyribose d. Thymine
a
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? a. competitive inhibition b. allosteric inhibition c. saturation of the enzyme activity d. denaturization of the enzyme
a
Osmosis refers to... a. the diffusion of water across a selectively permeable barrier b. the diffusion of ions across a selectively permeable barrier c.the diffusion of solutes across a selectively permeable barrier d. all of these answers are correct
a
Oxygen (O) is much more electronegative than hydrogen (H). Which of the following statements about water (H2O) is correct? A. Each hydrogen atom has a partial positive charge. B. The oxygen atom has a strong positive charge. C. Each hydrogen atom has a partial negative charge. D. Each hydrogen atom has a strong negative charge.
a
The ATP made during glycolysis is generated by a. substrate-level phosphorylation. b. chemiosmosis. c. oxidation of NADH to NAD+. d. electron transport.
a
The activation energy of an uncatalyzed reaction is A. greater than that of the enzyme-catalyzed reaction. B. less than that of the enzyme-catalyzed reaction. C. equal to that of the enzyme-catalyzed reaction. D. of no relation to that of the enzyme-catalyzed reaction.
a
The bonds between atoms in a polysaccharide are covalent bonds. The covalent bond formed between two monosaccharides is called A. a glycosidic linkage. B. a polysaccharide. C. a peptide bond. D. a cellulose bond.
a
The correct order of the following atoms, from most to least electronegative, is a. oxygen, nitrogen, carbon, hydrogen b. oxygen, carbon, nitrogen, hydrogen c. hydrogen, carbon, nitrogen, oxygen d. nitrogen, carbon, oxygen, hydrogen
a
Which part(s) of the cellular catabolism of glucose requires molecular oxygen (O2) and produces CO2? a. glycolysis b. the citric acid cycle (Krebs cycle) c. the combination of glycolysis and the citric acid cycle (Krebs cycle) d. the combination of the citric acid cycle (Krebs cycle) and the electron transport chain
b
in glycolysis, for each molecule of glucose oxidized to pyruvate... a. four molecules of ATP are used and two molecules of ATP are produced b. two molecules of ATP are used and four molecules of ATP are produced c. two molecules of ATP are used and two molecules of ATP are produced d. six molecules of ATP are used and six molecules of ATP are produced
b
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by a. hydrogen bonds. b. polar covalent bonds. c. nonpolar covalent bonds. d. van der Waals interactions.
b
In some plant species, alternate modes of carbon fixation have evolved to minimize Photorespiration and optimize the Calvin cycle. The goal of these alternate modes of carbon fixation is to A. Maintain a high concentration of O2 B. Maintain a high concentration of CO2 C. Increase the sensitivity of the plant leaf to light. D. Reduce the sensitivity of the plant leaf to light.
b
In the following fermentation reaction, which molecule is oxidized? Pyruvate + NADH + H+ ----> Lactate + NAD+ a. pyruvate b. NADH c. NAD+ d. lactate
b
Monosaccharides are linked to one another to form a polysaccharide by A. peptide bonds. B. splitting out H and OH, which form water. C. hydrogen bonds. D. phosphate connectors.
b
Of the following molecules, which is the most hydrophilic? A. Carbon Monoxide B. Glucose C. Carbon dioxide D. lipid
b
One of the reasons that the action of enzymes is highly specific is because... a. they have highly complex structures. b. the shape of the active site is complementary to the shape of the reactant(s). c. they donate free energy to the reactant. d. they lower the activation energy of the reaction.
b
Saturated fats a. have fatty acid chains that pack together loosely and so tend to be liquids at room temperature b. have fatty acid chains that pack together closely and so tend to be solids at room temperature c. contain at least one double bond d. contain all branched fatty acid chains
b
Some substances such as oil and gasoline will not dissolve in water because a. oil and gasoline are organic compounds. b. their molecules have no charges or partial charges to which water molecules can interact. c. their molecules are so large. d. their electrons are so stable that they do not exchange atoms with water molecules.
b
The activation energy of an enzyme-catalyzed reaction is a. equal to that of the uncatalyzed reaction. b. less than that of the uncatalyzed reaction. c. of no relation to that of the uncatalyzed reaction. d. greater than that of the uncatalyzed reaction.
b
The bonds in a water molecule are a. ionic bonds b. polar covalent bonds c. hydrogen bonds d. non-polar covalent bonds
b
The endomembrane system is composed of all of the following except A. golgi apparatus B. nucleolus C. endoplasmic reticulum D. lysosomes
b
The oxygen released by photosynthesis comes from the A. splitting of carbon dioxide B. splitting of water. C. reduction of carbohydrate. D. oxidation of carbohydrate.
b
The presence of cholesterol in the plasma membranes of some animals a. enables the animal to remove hydrogen atoms from saturated phospholipids. b. enables the membrane to stay fluid more easily when cell temperature drops. c. acts in transport of water molecules across the phopholipid bilayer d. enables the animal to add hydrogen atoms to unsaturated phospholipids.
b
The tertiary structure of a protein is the a. order in which amino acids are joined in a polypeptide chain. b. unique three-dimensional shape of the fully folded polypeptide. c. overall protein structure resulting from the association of two or more polypeptides. d. organization of a polypeptide chain into an α helix or β pleated sheet.
b
There are four levels of protein structure. Which level of structure contains coils and folds called α-helices and β-pleated sheets? A. primary. B. secondary. C. tertiary. D. quaternary.
b
What is the maximum number of electrons in the 1s orbital of an atom? a. 3 b. 2 c. 4 d. 1
b
Which of the following are capable of converting light energy to chemical energy? a. mitochondria b. chloroplasts c. leucoplasts d. peroxisomes
b
Which of the following is TRUE of the lytic cycle A. allows replication of the phage genome without destroying the host cell B. culminates in the death of the host cell C. indicates the phage is temperate D. only occurs in viroids and prions.
b
Which of the following statements is correct about diffusion? Select one: a. It requires integral proteins in the cell membrane. b. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. c. It requires an expenditure of energy by the cell. d. It is an active process in which molecules move from a region of lower concentration to one of higher concentration.
b
Which of the following statements regarding atomic particles is correct? a. Electrons are negatively charged, protons are neutral and neutrons are neutral. b. Electrons are negatively charged, protons are positively charged and neutrons are neutral. c. Electrons are negatively charged, protons are positively charged and neutrons are positively charged. d. Electrons are negatively charged, protons are positively charged and neutrons are negatively charged.
b
Which of the following statements regarding enzymes is TRUE? Select one: a. Enzymes decrease the free energy 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.
b
Which of the following statements regarding enzymes is TRUE? a. Enzymes decrease the free energy of a reaction b. Enzymes increase the rate of reaction c. Enzymes are permanently altered by the reactions they catalyze d.Enzymes change the direction of chemical reactions
b
Which of the following statements regarding integral membrane proteins is TRUE? a. They serve only a structural role in membranes b. they are usually transmembrane proteins. c.They are loosely bound to the surface of the bilayer d. they are not mobile within the bilayer.
b
Which of the following would NOT be found in a eukaryotic plant cell? A. plasma membrane B. lysosomes C. enzymes D. DNA
b
Which of the following would be most likely mechanism used by a protein exiting a cell? a. endocytosis b. exocytosis c. phagocytosis d. passive diffusion
b
A general term for the repeating units that are assembled to form polymers is: Select one: a. buildmers b. polyblocks c. domains d. monomers
d
Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that... a. the atom may become a radioactive isotope. b. an electron may move to an electron shell closer to the nucleus. c. the atom would become a negatively charged ion, or anion. d. an electron may move to an electron shell farther away from the nucleus.
d
If a newly synthesized protein is to be secreted by a cell, what would be its most likely pathway of movement from synthesis to secretion? a. endoplasmic reticulum----vesicles that fuse with the plasma membrane-----lysosomes b. Golgi apparatus----ER-----lysosome c. ER------Golgi-----nucleus d. ER------Golgi------vesicles that fuse with the plasma membrane
d
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? a. It is used to power yet more cellular work b. It is used to store energy as more ATP c. It is used to generate ADP from nucleotide precursors d. It is lost to the environment
d
Which of the following best describes enthalpy (H)? a. the total kinetic energy of a system b. the system's entropy c. the condition of a cell that is not able to react d. in biological systems, enthalpy is equivalent to total energy
d
Which of the following contains its own DNA and ribosomes? Select one: a. lysosome b. vacuole c. peroxisome d. chloroplast
d
Which of the following is (are) TRUE for anabolic pathways? Select one: a. They do not depend on enzymes. b. They are usually highly spontaneous chemical reactions. c. They release energy as they degrade polymers to monomers. d. They consume energy to build up polymers from monomers.
d
Which of the following is NOT an emergent property of water? A. versatile solvent. B. cohesion. C. high specific heat. D. low specific heat.
d
Which of the following is a characteristic of the lytic cycle? a. many bacterial cells containing viral DNA are produced b. viral DNA is incorporated into the host genome c. the viral genome replicates without destroying the host d. a large number of phages are released and the host cell is destroyed.
d
Which of the following makes ATP in the cell? a. peroxisome b. vacuole c. lysosome d. mitochondrion
d
Which of the following statements about membrane structure is true? A. Membrane proteins are spread in a continuous layer over both surfaces of the membrane. B. Phospholipids are only found in certain types of membranes. C. Peripheral membrane proteins are associated with the hydrophobic portion of the plasma membrane. D. Membrane fluidity increases with an increase in the amount of unsaturated fatty acids.
d
Which of the following statements about proton gradients is FALSE? a. A proton gradient is present when the concentration of hydrogen ions is higher on one side of a biological membrane than on the other side b. A proton gradient is present when the concentration of protons is higher on one side of a biological membrane than on the other side c. Proton gradients contain potential energy d. Proton gradients cannot be used to do work
d
Which of the following statements regarding enzymes is true? a. Enzymes increase the rate of a reaction by making the reaction more exergonic b. Enzymes change the equilibrium point of the reactions they catalyze c. Enzymes increase the rate of a reaction by reducing the rate of reverse reactions d. Enzymes increase the rate of a reaction by lowering the activation energy barrier
d
Which subatomic particles are directly involved in chemical reactions between atoms? a. nuclei b. neutrons c. protons d. electrons
d
The chemical reaction that combines sodium and chlorine and results in a final product of table salt is an example of...
Emergent properties
A DNA Strand contains A. the nitrogenous base; adenine, guanine, cytosine or thymine. B. ribose sugars. C. three phosphate groups attached to each 3' OH on its pentose sugar. D. the nitrogenous base adenine, guanine, cytosine or uracil.
a
A covalent bond is the result of A. two atoms that are sharing a pair of valence electrons. B. bonding between two oppositely charged ions. C. bonding between a sodium atom and a chlorine atom. D. many weak ionic attractions.
a
Amphipathic molecules... a. have both hydrophilic and hydrophobic b. have both positively charged and negatively charged regions c. have the midfield carbohydrates d. are only found in membranes
a
An element is made up of atoms. An atom is made up of subatomic particles. Which of those subatomic particles is negatively charged? A. electrons. B. protons. C. neutrons. D. all of the above.
a
Bound ribosomes... a. all of these answers are correct b. make proteins that are exported out of the cell c. make proteins that are inserted into the plasma membrane d. make proteins that are sent to the membrane of certain organelles
a
Cells can be described as having a cytoskeleton of internal structures that contribute to the shape, organization and movement of the cell. Which of the following is a part of the cytoskeleton? a. microfilaments b. cellulose microfibrils c. calcium depositories d. glycogen
a
The enzymes responsible for Calvin cycle are located in A. the Stroma. B. the mitochondria. C. the thylakoid membrane D. the nucleus.
a
The order of chemical bonds from easiest to hardest to break is... a. van der Waals interactions, hydrogen bonds, ionic bonds in the formation of salt crystals, covalent bonds b. covalent bonds, ionic bonds in the formation of salt crystals, van der Waals interactions, hydrogen bonds c. covalent bonds, ionic bonds in the formation of salt crystals, hydrogen bonds, van der Waals interactions d. ionic bonds in the formation of salt crystals, covalent bonds, hydrogen bonds, van der Waals interactions
a
The reactions of the Calvin cycle are a. endergonic, and thus require a source of free energy to occur b. endergonic, and thus may proceed spontaneously without a source of free energy c. exergonic, and thus require a source of free energy to occur d. exergonic, and thus may proceed spontaneously without a source of free energy
a
Unsaturated fats a. contain at least one covalent double bond joining two carbon atoms (i.e. C=C) b. contain at least one branched fatty acid molecule c. dissolve more readily in water d. are solid at room temperature
a
Water has a high specific heat because a. Much of the energy absorbed by water goes to breaking hydrogen bonds between water molecules, rather than to raising the temperature of the water. b. The bonds between the hydrogen and oxygen atoms in a water molecule are polar covalent bonds c. Liquid water is denser than frozen water (i.e. ice) d. Water is an excellent solvent
a
When chemical, transport or mechanical work is done by an organism, what happens to the heat generated? Select one: a. It is lost to the environment. b. It is transported to specific organs such as the brain. c. It is used to store more energy as ATP. d. It is used to power yet more cellular work.
a
Where do the enzymatic reactions of the Calvin cycle take place? a. stroma of the chloroplast b. thylakoid membranes c. thylakoid space d. matrix of the mitochondria
a
Which metabolic pathway is common to both cellular respiration and fermentation? Select one: a. glycolysis b. the oxidation of pyruvate to acetyl CoA c. oxidative phosphorylation d. the citric acid cycle
a
Which of the following are structural polysaccharides? a. cellulose and chitin b. glycogen and starch c. starch and chitin d. glycogen and cellulose
a
Which of the following contains its own DNA and ribosomes? Select one: a. chloroplast b. vacuole c. peroxisome d. lysosome
a
Which of the following contains its own DNA and ribosomes? a. chloroplasts b. lysosome c. vacuole d. peroxisome
a
Which of the following does not occur during the Calvin cycle in photosynthesis? a. release of oxygen b. consumption of ATP c. carbon fixation d. oxidation of NADPH
a
Which of the following relationships between cell structures and their respective functions is CORRECT? a. cell wall; support, protection b. ribosomes; secretion c. chloroplasts; chief sites of cellular respiration d. chromosomes: cytoskeleton of the nucleus
a
Which of the following statements about the nucleotides used in DNA synthesis is CORRECT? a. The nucleotides used in DNA synthesis have deoxyribose as their sugar component and do not include nucleotides that have uracil as their nitrogenous base. b. The nucleotides used in DNA synthesis have deoxyribose as their sugar component and do not include nucleotides that have thymine as their nitrogenous base. c. The nucleotides used in DNA synthesis have ribose as their sugar component and do not include nucleotides that have thymine as their nitrogenous base. d. The nucleotides used in DNA synthesis have ribose as their sugar component and do not include nucleotides that have uracil as their nitrogenous base.
a
Which of the following statements is TRUE about anabolic pathways? A. They combine molecules into more complex and energy-rich molecules. B. They involve exergonic reactions that break complex molecules into simpler ones. C. They do not need enzyme catalysis. D. They involve spontaneous reactions that do not require an input of energy.
a
Which of the following would decrease the entropy within a system? A. dehydration reaction B. hydrolysisreaction C. catabolism D. oxidation of glucose to CO2 and H2O
a
Which subatomic particles are directly involved in chemical reactions between atoms? a. electrons b. neutrons c. nuclei d. protons
a
Which of the following is not a molecule? Select one: a. NaCl b. CH4 c. H2O d. H2
a (NaCl is not a molecule. It is the formula of an ionic compound. In the solid form, the ions are held together by an electrostatic attraction between the positive and negaitve charges. When dissolved in water, the ions can move separatelty from each other. The atoms in a molecule would move as a single unit.)
A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the following would be expected to occur? a. the plants would develop some but not all of the symptoms of the TMV infection b. The plants would develop symptoms typically produced by viroids. b. The plants would develop the typical symptoms of the TMV infection c. The plants would not show any disease symptoms
b
A temperate phage A. is called a provirus when it integrates into the genome. B. has both a lytic and lysogenic cycle. C. has only a lytic cycle. D. has only a lysogenic cycle.
b
ATP generally activates a cellular process by A. releasing heat upon hydrolysis. B. direct chemical transfer of a phosphate group. C. direct chemical transfer of a sugar group. D. becoming oxidized.
b
An electron exists in a 3-dimensional space called a(n) A. electron carrier. B. orbital. C. electrone. D. hydration shell
b
An example of a hydrogen bond is the bond between: a. the two hydrogen atoms in a molecule of hydrogen gas b. the H of one water molecule and the O of another water molecule c. C and H in methane d. Mg+ and Cl- in MgCl2
b
Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________. a. exergonic; spontaneous b. exergonic; endergonic c. free energy; entropy d. entropy; enthalpy
b
Compounds with hydroxyl groups are known as Select one: a. ketones b. alcohols c. aldehydes d. thiols
b
How can one increase the rate of a chemical reaction? Select one: a. Increase the activation energy needed. b. Add a catalyst c. Cool the reactants. d. Increase the entropy of the reactants.
b
How does a scientific hypothesis differ from a scientific theory? A. Theories treat more specific issues, while a hypothesis is an explanation for a very general phenomenon. B. A hypothesis is a proposed explanation for a more specific observation, whereas a theory is a well-supported explanation for a very general phenomenon or observation. C. Theories must be both testable and falsifiable, while hypotheses by definition cannot be either tested or falsified. D. There is no difference—in science, hypotheses and theories are the same thing.
b
If you examine the biological hierarchy at a molecular level, new properties exist at one level which, were not present at the preceding level. These novel properties are called A. increasing hierarchy properties. B. emergent properties. C. high level properties. D. low level properties.
b
A student was asked to draw a structure where all of the atoms involved had a complete valence shell. Why is the structure shown below incorrect? H-C=C-H a. Carbon is more electronegative than hydrogen and should thus remove electrons from hydrogen, rather than forming a covalent bond with hydrogen. b. Each carbon atom only has 3 covalent bonds. c. The two carbon atoms share more than 1 bond. d. Each hydrogen atom only has 1 covalent bond.
b (Carbon atoms need to form 4 covalent bonds, rather than just 3, to complete their valence shell. Carbon is only slightly more electronegative than hydrogen and so will not remove electrons from hydrogen. )
Polysaccharides, nucleic acids, and proteins are similar in that they a. all contain nitrogen in their monomer building blocks b. are synthesized from monomers by dehydration reactions c. are decomposed into monomers by dehydration reactions d. are synthesized from monomers by the process of hydrolysis
b (They are synthesized from monomers, but synthesis occurs via dehydration reactions.)
In the following fermentation reaction, which molecule is oxidized? Pyruvate + NADH + H+ ----> Lactate + NAD+ a. NAD+ b. NADH c. lactate d. pyruvate
b NADH is oxidized
A hypothesis... A. can be proven by inductive reasoning. B. can be proven by deductive reasoning. C. Is formulated in the scientific process after a question is asked. D. Is formulated in the scientific process before observations are made.
c
A mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells? a. The mutant yeast will be unable to metabolize glucose. b. The mutant yeast will grow anaerobically only when given glucose. c. The mutant yeast will be unable to grow anaerobically. d. The mutant yeast will die because they cannot regenerate NADH from NAD+.
c
A patient had a serious accident and lost a lot of blood. In an attempt to replenish body fluids,distilled water, equal to the volume of the blood lost,is transferred directly into on of his/her veins. What will be the most probable result of this transfusion? a. The red blood cells will shrink because the blood fluid is hypotonic compared to the red blood cells b. the red blood cells will shrink because the blood fluid is hypertonic compared to the red blood cells c. the red blood cells will expand and possibly burst because the blood fluid is hypotonic compared to the red blood cells d. the red blood cells will expand and possibly burst because the blood fluid is hypertonic compared to the red blood cells
c
A student was asked to draw a structure where all of the atoms involved had a complete valence shell. Why is the structure shown below incorrect? H-C=C-H a. The two carbon atoms share more than 1 bond. b. Carbon is more electronegative than hydrogen and should thus remove electrons from hydrogen, rather than forming a covalent bond with hydrogen. c. Each carbon atom only has 3 covalent bonds. d. Each hydrogen atom only has 1 covalent bond.
c
An ionic bond is the result of A. two atoms that are sharing a pair of valence electrons. B. bonding between a carbon atom and four hydrogen atoms. C. bonding between a sodium ion and a chloride ion. D. bonding between only hydrogen ions.
c
Bound ribosomes Select one: a. make proteins that are inserted into the plasma membrane b. make proteins that are exported out of the cell c. all of these answers are correct d. make proteins that are sent to the membrane of certain organelles
c
Bound ribosomes Select one: a. make proteins that are sent to the membrane of certain organelles b. make proteins that are inserted into the plasma membrane c. all of these answers are correct d. make proteins that are exported out of the cell
c
Cellular membranes consist of a variety of components. Which component is necessary to facilitate transport of ions and polar molecules across the membrane. A. phospholipid. B. cholesterol. C. protein. D. carbohydrate
c
Citric acid makes lemons taste sour. Which of the following is a functional group that would cause a molecule like citric acid to be acidic? A. hydroxyl B. hydrocarbon C. carboxyl D. carbonyl
c
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by a. nonpolar covalent bonds. b. van der Waals interactions. c. polar covalent bonds. d. hydrogen bonds.
c
Increasing substrate concentration in an enzymatic reaction could overcome which of the following? A. enzyme denaturation B. allosteric inhibition C. competitive inhibition D. noncompetitive inhibition
c
Of the following functions, which is most important for the glycoproteins and glycolipids in animal cell membranes? a. Facilitated diffusion of molecules down their concentration gradients b. maintaining membrane fluidity at low temperatures c. helping cells distinguish one type of neighboring cells from another d. active transport of molecules against their concentration gradients
c
One of the reasons that the action of enzymes is highly specific is because Select one: a. they donate free energy to the reactant. b. they have highly complex structures. c. the shape of the active site is complementary to the shape of the reactant(s). d. they lower the activation energy of the reaction.
c
Ribosomes A. are very rare in eukaryotes. B. are used directly to detoxify alcohol and other drug compounds. C. are the organelles that synthesize proteins. D. all of the above.
c
The enzyme that attaches CO2 to a 5-carbon long sugar to form a 6-carbon long molecule is a. polymerase b. carbon dioxide synthase c. ribulose bisphosphate carboxylase oxygenase, or "Rubisco" d. photosynthase
c
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction a. gains electrons. b. increases electrons in solution. c. loses electrons. d. decreases electrons in solution.
c
The monomer of polypeptides contains all of the following EXCEPT a. a carboxyl group. b. nitrogen. c. a phosphate. d. an "R" group connected to one of the carbons.
c
The products of the "Light Reactions" of photosynthesis are... A. NADH + H+, glucose, and oxygen. B. NADPH + H+, glucose, and carbon dioxide. C. NADPH + H+, ATP, and oxygen. D. carbon dioxide, ATP, and NADH + H+.
c
The proteins found in chloroplasts... a. are encoded by DNA in the chloroplast, nucleus or mitochondria b. are encoded only by DNA in the nucleus c. are encoded either by DNA in the chloroplast or by nuclear DNA d. are encoded only by DNA in the chloroplast
c
When the pH of a solution shifts from 7 to 3, how has the hydrogen ion concentration changed? A. It has increase by 4 times. B. It has decreased by 4 times. C. It has increased by 10,000 times D. It has decreased by 10,000 times
c
When two atoms share a pair of electrons, they a. form a paired bond b. form an ionic bond c. form a covalent bond d. form an electrical bond
c
Where does glycolysis take place in eukaryotic cells? a. mitochondrial inner membrane b. mitochondrial matrix c. cytosol d. mitochondrial intermembrane space
c
Which of the following are commonly made by the rough endoplasmic reticulum (ER)? a. proteins in the membrane of cellular organelles b. proteins in the plasma membrane of the cell c. all of these answers are correct d. proteins secreted from the cell
c
Which of the following is NOT true of viral capsids? A. Consist of a protein shell, which encloses the viral genome B. Shape is variable C. Derived from the membrane of the host cell D. Composed of a large number of capsomere subunits
c
Which of the following is an example of potential rather than kinetic energy? a. an increase in air temperature as a meteor passes through the atmosphere b. a hockey puck hitting the boards c. a food molecule d. water flowing in a river
c
Which of the following results from a transfer of electron(s) between atoms? a. a polar covalent bond b. a hydrogen bond c. an ionic bond d. a nonpolar covalent bond
c
Which of the following results from a transfer of electrons between atoms? a. a nonpolar covalent bond b. a hydrogen bond c. an ionic bond d. polar covalent bonds
c
Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein? a. +∆S, -∆G b. +∆S, +∆G c. -∆S, +∆G d. -∆S, -∆G
c
Which of the following statements about glycolysis is NOT true? A. glycolysis has steps involving oxidation-reduction reactions. B. glycolysis can operate in the complete absence of oxygen. C. the end products of glycolysis are CO2 and H2O. D. ATP and NADH are generated during glycolysis.
c
Which of the following statements about proton gradients is FALSE? a. A proton gradient is present when the concentration of protons is higher on one side of a biological membrane than on the other side b. Proton gradients contain potential energy c. Proton gradients cannot be used to do work d. A proton gradient is present when the concentration of hydrogen ions is higher on one side of a biological membrane than on the other side
c
Which of the following statements about the nucleotides used in RNA synthesis is CORRECT? a. The nucleotides used in RNA synthesis have ribose as their sugar component and do not include nucleotides that have uracil as their nitrogenous base. b. The nucleotides used in RNA synthesis have deoxyribose as their sugar component and do not include nucleotides that have uracil as their nitrogenous base. c. The nucleotides used in RNA synthesis have ribose as their sugar component and do not include nucleotides that have thymine as their nitrogenous base. d. The nucleotides used in RNA synthesis have deoxyribose as their sugar component and do not include nucleotides that have thymine as their nitrogenous base.
c
Which of the following statements concerning saturated fats is NOT true? a. They are more common in animals than in plants. b. They contain more hydrogen than unsaturated fats having the same number of carbon atoms. c. They have multiple double bonds in the carbon chains of their fatty acids. d. They generally solidify at room temperature.
c
Which of the following statements regarding atomic particles is correct? a. Electrons are negatively charged, protons are positively charged and neutrons are negatively charged. b. Electrons are negatively charged, protons are positively charged and neutrons are positively charged. c. Electrons are negatively charged, protons are positively charged and neutrons are neutral. d. Electrons are negatively charged, protons are neutral and neutrons are neutral.
c
Which of these often serve as cell recognition molecules on cell surfaces? a. transmembrane proteins b. peripheral proteins c. glycoproteins d. integral proteins
c
Monosaccharides are added to growing polysaccharide chains via condensation (dehydration) reactions. Which of the following also occur via condensation (dehydration) reactions? a. Attaching fatty acids to glycerol molecules b. Attaching nucleotides to growing DNA molecules c. All of these answers are correct d. Attaching amino acids to growing polypeptide chains
c (All of the reactions we discussed involving synthesis of large biological molecules take place via a type of condensation reaction known as a dehydration reaction that involves the loss of a water molecule (hence the name "dehydration" for water removal).)
Which of the following are examples of types of secondary structures of proteins? a. beta pleated sheets and peptide bonds b. peptide bonds and disulfide bridges c. alpha helices and beta pleated sheets. d. alpha helices and disulfide bridges
c (Alpha helices and beta pleated sheets are examples of secondary structures found in proteins. In contrast, disulfide bridges play a role in formation of protein tertiary structure and peptide bonds link adjacent amino acids and so play a role in primary structure.)
Which of the following would you expect to dissolve poorly in water? a. a substance with a lot of polar covalent bonds b. Anions c. A substance with a lot of nonpolar covalent bonds d. cations
c -Water molecules are polar molecules as they carry partial positive and negative charges on different parts of the molecule. As a result, water molecules will tend to interact with other molecules that carry partial or full charges, including molecules with polar bonds, negatively charged molecules and atoms and positively charged molecules and anions.
If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that a. the concentration of H+ ions in the cytoplasm is 7/8 the concentration in the mitochondrial matrix. b. the concentration of H+ ions is tenfold higher in the mitochondrial matrix than in the cytoplasm. c. the mitochondrial matrix is more acidic than the cytoplasm. d. the concentration of H+ ions is tenfold higher in the cytoplasm than in the mitochondrial matrix.
d
In a plant cell, where are the ATP synthase complexes located? a. thylakoid membrane and plasma membrane b. thylakoid membrane only c. plasma membrane only d. thylakoid membrane and inner mitochondrial membrane
d
In glycolysis, for each molecule of glucose oxidized to pyruvate a. two molecules of ATP are used and six molecules of ATP are produced. b. six molecules of ATP are used and six molecules of ATP are produced. c. two molecules of ATP are used and two molecules of ATP are produced. d. two molecules of ATP are used and four molecules of ATP are produced. e. four molecules of ATP are used and two molecules of ATP are produced.
d
In photosynthesis, reactions that require CO2 take place in a. both the light reactions and the Calvin cycle. b. neither the light reactions nor the Calvin cycle. c. the light reactions alone. d. the Calvin cycle alone.
d
In photosynthesis, the reactions that produce molecular oxygen (O2) take place in a. both the light reactions and the Calvin cycle. b. neither the light reactions nor the Calvin cycle. c. the Calvin cycle alone. d. the light reactions alone.
d
In the 3-Domain system of classification, organisms that do not contain a nucleus are represented by: A. archaea. B. bacteria. C. prokaryotes. D. all of the above.
d
Lipids that are commonly found in cell membranes include a. triacylglycerol and cholesterol b. triacylglycerol, cholesterol and phospholipids c. phospholipids and cholesterol d. phospholipids and triacylglycerol
d
Lipids that contain one or more C=C double bonds are referred to as a. triacylglycerols b. phospholipids c. saturated fats d. unsaturated fats
d
Starting with one molecule of glucose, the energy-containing products of glycolysis are a. 6 CO2, 2 ATP, and 2 pyruvate. b. 2 FADH2, 2 pyruvate, and 4 ATP. c. 2 NAD+, 2 pyruvate, and 2 ATP. d. 2 NADH, 2 pyruvate, and 2 ATP.
d
The oxygen released by photosynthesis comes from the Select one: a. reduction of carbohydrate. b. oxidation of carbohydrate. c. splitting of carbon dioxide. d. splitting of water.
d
The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water, is an example of A. a catabolic pathway. B. an energy releasing pathway. C. a pathway in which the entropy of the system increases. D. all of the above.
d
The products of the "Light Reactions" of photosynthesis are a. NADPH + H+, glucose, and carbon dioxide. b. carbon dioxide, ATP, and NADH + H+. c. NADH + H+, glucose, and oxygen. d. NADPH + H+, ATP, and oxygen.
d
The rate of an enzyme-catalyzed reaction is reduced at low temperatures because A. the shape of the enzyme is altered. B. there are fewer substrate molecules present. C. there are fewer enzyme molecules present. D. there is not enough energy in the system for the reaction to proceed.
d
What is a triacylglycerol? a. a protein with a tertiary structure b. a lipid that makes up much of the plasma membrane c. A molecule formed from three alcohols by dehydration reactions d. a lipid made with three fatty acids and a glycerol
d
What is the difference between covalent bonds and ionic bonds? Select one: a. Covalent bonds involve the transfer of electrons between atoms; ionic bonds involve the sharing of electrons between atoms. b. Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. c. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between atoms. d. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms.
d
What is the primary function of the Calvin cycle? a. use NADPH to release carbon dioxide b. use ATP to release carbon dioxide c. split water and release oxygen d. synthesize simple sugars from carbon dioxide
d
What would be an expected consequence of changing one amino acid for a different amino acid in a particular protein? A. The primary structure would be changed. B. The tertiary structure might be changed. C. The biological activity of this protein might be altered. D. All of the above are possible.
d
which of the following statements about the 5' end of a polynucleotide strand of DNA is correct? a. The 5' end has a carboxyl group attached to the number 5 carbon of ribose. b. The 5' end is the fifth position on one of the nitrogenous bases. c. The 5' end has phosphate attached to the number 5 carbon of the nitrogenous base. d. The 5' end has a phosphate group attached to the number 5 carbon of deoxyribose.
d
Which of the following are NOT components of nucleotides? a. a sugar b. a nitrogenous base c. a phosphate group d. an "R" group attached to a central carbon atom
d (An "R" group attached to a central atom is a component of an amino acid rather than a nucleotide.)
With regards to orbitals, which of the following statements is FALSE? a. An orbital is occupied by one or two electrons. b. An orbital can be depicted as a cloud where an electron may be located. c. An orbital is a region surrounding the nucleus where the probability of finding an electron is high. d. An orbital is a defined path that an electron follows as it orbits the nucleus.
d (Electrons do not follow defined paths and the position of an electron cannot be precisely known. Instead, we can only say that there is a high probability of a particular electron being located somewhere within a space defined by the orbital for that electron.)
Which of the following statements about electrons is FALSE? a. two electrons may occupy the same electron orbital b. electrons are negatively charged c. electrons are attracted to nuclei by the positive charges of the protons in the nuclei d. the closer an electron is to the nucleus, the more strongly the electron is attracted to the nucleus and therefore the more potential energy the electron has
d (It is true that the closer an electron is to the nucleus, the more strongly the electron is attracted to the nucleus. However, it is NOT true that an electron has more potential energy when it is closer to the nucleus. In fact, it will have less potential energy the closer it gets to the nucleus. Think of it this way, the further from the earth you send a rocket, the less strongly it is attracted to the earth by gravity, but the more potential energy it has.)
Which term includes all the other terms on the list? Select one: a. polysaccharide b. monosaccharide c. starch d. carbohydrate
d (polysaccharides, monosaccharides, starches, and all types of sugars are all considered carbohydrates)
Which part(s) of the cellular catabolism of glucose requires molecular oxygen (O2) and produces CO2? a. the combination of the citric acid cycle (Krebs cycle) and the electron transport chain b. the citric acid cycle (Krebs cycle) c. the combination of glycolysis and the citric acid cycle (Krebs cycle) d. glycolysis
not b SOLVE
What does a hydration shell look like?
water molecules form around a solute
