BSC 1010C Ch1-10 & 12-14 & 16 Tests FINAL EXAM
Which statement about a methyl functional group is correct? 1. A methyl group consists of a carbon bonded to three hydrogen atoms. 2. A methyl group may be negatively charged. 3. A methyl group is polar.
1. A methyl group consists of a carbon bonded to three hydrogen atoms.
Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results? 1. Decreasing graph 2. Increasing graph 3. line
1. Decreasing graph
Why are hydrocarbons insoluble in water? 1. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. 2. They exhibit considerable molecular complexity and diversity. 3. The majority of their bonds are polar covalent carbon-to-hydrogen linkages. 4. They are less dense than water.
1. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
Which of the following statements is true about chemical nutrients in an ecosystem? 1. They recycle within the ecosystem, being constantly reused. 2. They cannot be obtained from decomposition. 3. They exit the ecosystem in the form of heat. 4. They flow through the system, losing some nutrients in the process. 5. They depend on sunlight as their source.
1. They recycle within the ecosystem, being constantly reused.
Can the atomic mass of an element vary? 1. Yes. Adding or losing neutrons will change the atomic mass without forming a different element. 2. No, it is fixed. If it changes at all then you have formed a different element. 3. Yes. Adding or losing protons will change the atomic mass without forming a different element. 4. Yes. Adding or losing electrons will substantially change the atomic mass.
1. Yes. Adding or losing neutrons will change the atomic mass without forming a different element.
What is the correct order for the hierarchy of biological organization from the least to the most complex? 1. molecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem 2. molecule, organelle, cell, tissue, organ, organ system, organism, population, ecosystem, community 3. molecule, organelle, cell, tissue, organ, organ system, organism, ecosystem, community, population 4. molecule, organelle, tissue, cell, organ, organ system, organism, population, community, ecosystem 5. molecule, cell, tissue, organelle, organ, organ system, organism, population, community, ecosystem
1. molecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem
Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that _____. 1. the concentration of hydrogen ions in solution X is 1000 times as great as the concentration of hydrogen ions in solution Y 2. the concentration of hydrogen ions in solution X is 3 times as great as the concentration of hydrogen ions in solution Y 3. solution Y has no free hydrogen ions (H+) 4. the concentration of hydrogen ions in solution Y is 1000 times as great as the concentration of hydrogen ions in solution X
1. the concentration of hydrogen ions in solution X is 1000 times as great as the concentration of hydrogen ions in solution Y
Variations in the reactive properties of different organic molecules are most closely associated with _____. 1. the presence or absence of functional groups 2. the presence or absence of double bonds 3. the number of carbon atoms comprising the molecule's skeleton 4. the number of asymmetric carbon atoms present 5. the orientation of the carbon skeleton, as either ringed or linear
1. the presence or absence of functional groups
Which of the following attributes is common to both prokaryotic cells and eukaryotic cells? 1. the use of DNA as the information storage molecule 2. a membrane-enclosed nucleus 3. generally about the same size 4. membrane-enclosed organelles 5. the use of proteins as information storage molecules
1. the use of DNA as the information storage molecule
Prokaryotes are classified as belonging to two different domains. What are the domains? 1. Bacteria and Protista 2. Bacteria and Archaea 3. Archaea and Fonera 4. Bacteria and Eukarya
2. Bacteria and Archaea
What is the difference between covalent bonds and ionic bonds? 1. Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. 2. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. 3. Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms. 4. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms.
2. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms.
Which of the following statements is true about buffer solutions? 1. They maintain a constant pH when acids are added to them but not when bases are added to them. 2. They maintain a relatively constant pH when either acids or bases are added to them. 3.They fluctuate in pH when either acids or bases are added to them. 4. They maintain a constant pH when bases are added to them but not when acids are added to them.
2. They maintain a relatively constant pH when either acids or bases are added to them.
When the atoms involved in a covalent bond have the same electronegativity, what type of bond results? 1. a hydrogen bond 2. a nonpolar covalent bond 3. an ionic bond 4. a polar covalent bond
2. a nonpolar covalent bond
About twenty-five of the ninety-two natural elements are known to be essential to life. Which four of these twenty-five elements make up approximately 96 percent of living matter? 1. carbon, oxygen, phosphorus, hydrogen 2. carbon, hydrogen, nitrogen, oxygen 3. oxygen, hydrogen, calcium, nitrogen 4. carbon, sodium, hydrogen, nitrogen
2. carbon, hydrogen, nitrogen, oxygen
An acid is a substance that _____. 1. reduces the hydrogen ion concentration of a solution 2. increases the hydrogen ion concentration of an aqueous solution 3. is a versatile solvent 4. forms covalent bonds with other substances 5. contains hydrogen
2. increases the hydrogen ion concentration of an aqueous solution
A localized group of organisms that belong to the same species is called a _____. 1. ecosystem 2. population 3. family 4. community
2. population
A controlled experiment is one that 1. proceeds slowly enough that a scientist can make careful records of the results. 2. tests experimental and control groups in parallel. 3. keeps all variables constant. 4. is repeated many times to make sure the results are accurate. 5. is supervised by an experienced scientist.
2. tests experimental and control groups in parallel.
From its atomic number of 15, it is possible to predict that the phosphorus atom has _____. 1) 8 electrons in its outermost electron shell 2) 5 neutrons, 5 protons, and 5 electrons 3) 15 protons and 15 electrons 4) 15 neutrons and 15 protons
3) 15 protons and 15 electrons
If an atom has a charge of +1, which of the following must be true? 1. It has the same number of protons as electrons. 2. It has one more electron than it does protons. 3. It has one more proton than it does electrons. 4. It has two more protons than neutrons.
3. It has one more proton than it does electrons.
Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely _____. 1. without charge 2. negatively charged 3. positively charged 4. nonpolar
3. positively charged
To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology? 1. feedback regulation 2. emergent properties 3. reductionism 4. evolution
3. reductionism
The application of scientific knowledge for some specific purpose is known as _____. 1. deductive science 2. inductive science 3. technology 4. pure science
3. technology
The partial negative charge in a molecule of water occurs because _____. 1. the oxygen atom donates an electron to each of the hydrogen atoms 2. the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms 3. the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus 4. one of the hydrogen atoms donates an electron to the oxygen atom
3. the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus
The type of bonding and the numbers of covalent bonds an atom can form with other atoms is determined by _____. 1. the nucleus 2. the number of protons 3. the number of unpaired electrons in the valence shell 4. the number of neutrons 5. the size of the atom; smaller atoms are chemically more reactive
3. the number of unpaired electrons in the valence shell
For each mole of glucose (C6H12O6) oxidized by cellular respiration, how many moles of CO2 are released in the citric acid cycle (see the accompanying figure)? 32 4 2 6
4
How many electron pairs does carbon share to complete its valence shell? 2 3 4 6 8
4
Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)? 1. Ammonia has an overall negative charge. 2. Ammonia has an overall positive charge. 3. The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge. 4. Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge.
4. Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge.
Which of the following correctly describes a reaction that has reached chemical equilibrium? 1. All of the reactants have been converted to the products of the reaction. 2. All of the products have been converted to the reactants of the reaction. 3. Both the forward and the reverse reactions have stopped, with no net effect on the concentration of the reactants and the products. 4. The rate of the forward reaction is equal to the rate of the reverse reaction.
4. The rate of the forward reaction is equal to the rate of the reverse reaction.
One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+), as noted below. H2CO3 <-> HCO3- + H+ If the pH of blood increases, one would expect _____. 1. an increase in the concentration of H2CO3 and a decrease in the concentration of HCO3- 2. a decrease in the concentration of HCO3- and an increase in the concentration of H+ 3. an increase in the concentration of HCO3- and a decrease in the concentration of OH- 4. a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-
4. a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-
What results from an unequal sharing of electrons between atoms? 1. a nonpolar covalent bond 2. an ionic bond 3. a hydrophobic interaction 4. a polar covalent bond
4. a polar covalent bond
Water molecules can form hydrogen bonds with _____. 1. chloride ions 2. oxygen gas (O2) molecules 3. oils 4. compounds that have polar covalent bonds
4. compounds that have polar covalent bonds
How would acidification of seawater affect marine organisms? Acidification of seawater would _____. 1. decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals 2. increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals 3. increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals 4. decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals
4. decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals
Because organisms are made primarily of water, they resist rapid temperature changes. This useful quality is based on water's _____. 1. lower density in the solid phase 2. buffering activity 3. cohesion 4. high specific heat 5. ability to form colloids
4. high specific heat
Which of these provides evidence of the common ancestry of all life? 1. structure of the nucleus 2. structure of cilia 3. structure of chloroplasts 4. near universality of the genetic code
4. near universality of the genetic code
Which branch of biology is concerned with the naming and classifying of organisms? 1. evolution 2. genomics 3. informatics 4. taxonomy
4. taxonomy
Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? 5´-AGCT-3´ with 5´-TCGA-3´ All of these pairs are correct. 5´-GCGC-3´ with 5´-TATA-3' 5´-purine-pyrimidine-purine-pyrimidine-3´ with 3´-purine-pyrimidine-purine-pyrimidine-5´ 5´-ATGC-3´ with 5´-GCAT-3´
5´-ATGC-3´ with 5´-GCAT-3´
The light reactions of photosynthesis supply the Calvin cycle with light energy. H2O and NADPH. CO2 and ATP. sugar and O2. ATP and NADPH.
ATP and NADPH.
400-450 nm 670-680 nm
Absorption and action spectra, along with a classic experiment by Theodor W. Engelmann, reveal which wavelengths of light are photosynthetically important. Which wavelengths of light drive the highest rates of photosynthesis? Select the two best answers. 400-450 nm 500-600 nm 550-700 nm 670-680 nm
How does an enzyme increase the rate of the chemical reaction it catalyzes? An enzyme reduces the free-energy change (ΔG) of the reaction it catalyzes. An enzyme reduces the free energy of activation (EA) of the reaction it catalyzes. An enzyme's active site binds only the reactants, and not the products of a reaction, pushing the equilibrium for the reaction far to the right.
An enzyme reduces the free energy of activation (EA) of the reaction it catalyzes.
Which of the following hydrocarbons has a double bond in its carbon skeleton? C2H2 C2H4 C2H6 CH4 C3H8
C2H4
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? glucose CO2 an amino acid K+
CO2
What is the basic role of CO2 in photosynthesis? CO2 is a source of electrons in the formation of organic molecules. CO2 is fixed or incorporated into organic molecules. CO2 is taken in by plants as a form of inverse respiration, in which carbon dioxide is "breathed in" and oxygen is "breathed out."
CO2 is fixed or incorporated into organic molecules.
The element present in all organic molecules is _____. oxygen hydrogen carbon nitrogen
Carbon
Both the volume and the surface area for three different cells were measured. These values are listed in the following table: Volume Surface Area Cell 1 9.3 μm3 26.5 μm2 Cell 2 12.2 μm3 37.1 μm2 Cell 3 17.6 μm3 40.6 μm2 Using data from the table above, select the best explanation for why that cell will be able to eliminate waste most efficiently? Cell 3 since it has the largest surface area which will enable it to eliminate all of its wastes quickly. Cell 1 since it has the smallest volume and will not produce as much waste as the other cells. Cell 3 because it is big enough to allow wastes to easily diffuse through the plasma membrane. Cell 2 since it has the highest surface area-to-volume ratio which facilitates the exchange of materials between a cell and its environment.
Cell 2 since it has the highest surface area-to-volume ratio which facilitates the exchange of materials between a cell and its environment.
Which of the following statements is representative of the second law of thermodynamics? Without an input of energy, organisms would tend toward decreasing entropy. Cells require a constant input of energy to maintain their high level of organization. Conversion of energy from one form to another is always accompanied by some gain of free energy. Every energy transformation by a cell decreases the entropy of the universe.
Cells require a constant input of energy to maintain their high level of organization.
Which molecule shown above contains a carboxyl group? (Flip to see photo) A B C D
D
Which of the following statements best summarizes the differences between DNA and RNA? DNA nucleotides contain a different sugar than RNA nucleotides. The bases in DNA contain sugars, whereas the bases in RNA do not contain sugar. DNA contains the base uracil, whereas RNA contains the base thymine. DNA encodes hereditary information, whereas RNA does not.
DNA nucleotides contain a different sugar than RNA nucleotides.
The flow of genetic information in a cell goes from _____. DNA to RNA to glucose DNA to RNA to protein DNA to ribosomes to RNA protein to RNA to DNA DNA to lipid to protein
DNA to RNA to protein
A cell has formed a food vacuole as it ingested a food particle. Which of the following events is associated with the breakdown of that food particle? Proteins for digestion of the food are made by ribosomes in the Golgi apparatus. The membrane of the food vacuole is derived from the cell wall. Digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm. Enzymes for the breakdown of the food are delivered to the food vacuole from the cytosol. Proteins for digestion of the food particle were initially processed in mitochondria.
Digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm.
What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell? Golgi → ER → lysosome nucleus → ER → Golgi ER → Golgi → vesicles that fuse with plasma membrane ER → lysosomes → vesicles that fuse with plasma membrane ER → Golgi → nucleus
ER → Golgi → vesicles that fuse with plasma membrane
Select the correct molecule that is the main product of the Calvin cycle. Glucose G3P NADPH
G3P
In the combined processes of glycolysis and cellular respiration, what is consumed and what is produced? ATP is consumed, and oxygen is produced. Glucose is consumed, and carbon dioxide is produced. Water is consumed, and ATP is produced. Carbon dioxide is consumed, and water is produced. Oxygen is consumed, and glucose is produced.
Glucose is consumed, and carbon dioxide is produced.
In solution, why do hydrolysis reactions occur more readily than condensation reactions? Hydrolysis increases entropy and is exergonic. Hydrolysis increases entropy and is endergonic. Hydrolysis decreases entropy and is exergonic. Hydrolysis raises G, or Gibbs free energy.
Hydrolysis increases entropy and is exergonic.
Which of the following is true of osmosis? In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration. Osmosis only takes place in red blood cells. Osmosis is an energy-demanding or "active" process. In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration.
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 characteristic feature of a carrier protein in a plasma membrane? It works against diffusion. It exhibits a specificity for a particular type of molecule. It has no hydrophobic regions. It requires the expenditure of cellular energy to function.
It exhibits a specificity for a particular type of molecule.
A glucose molecule is completely broken down to carbon dioxide and water in glycolysis and the citric acid cycle, but together these two processes yield only a few molecules of ATP. What happened to most of the energy that the cell obtains from the oxidation of glucose? It is stored in NADH and FADH2 It is stored in pyruvate. It was lost as heat. It is stored in the carbon dioxide and water molecules released by these processes. It is stored in the ATP that was formed by glycolysis and the citric acid cycle.
It is stored in NADH and FADH2
P680+ is said to be the strongest biological oxidizing agent. Given its function, why is this necessary? It is the molecule that transfers electrons to plastoquinone (Pq) of the electron transfer system. It obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has. It transfers its electrons to reduce NADP+ to NADPH. It is the receptor for the most excited electron in either photosystem of photosynthesis.
It obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has.
What compound provides the reducing power for Calvin cycle reactions? NADP+ NADPH ATP NADH
NADPH
Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean? Cells of each domain evolved proton pumps independently when oceans became more acidic. Proton pumps are necessary to all cell membranes. Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism.
Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
Most enzyme molecules are occupied by substrate at high reactant concentrations.
Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant. In the figure, why does the reaction rate plateau at higher reactant concentrations? The reaction nears equilibrium at high reactant concentrations. Feedback inhibition by product occurs at high reactant concentrations. The rate of the reverse reaction increases with reactant concentration. Most enzyme molecules are occupied by substrate at high reactant concentrations.
The basic function of the light reactions of photosynthesis is the conversion of solar energy to chemical energy.
Select the most accurate statement describing the basic function of the light reactions of photosynthesis. The basic function of the light reactions of photosynthesis is the production of glucose. The basic function of the light reactions of photosynthesis is the conversion of solar energy to chemical energy. The basic function of the light reactions of photosynthesis is the trapping of light energy.
Select the correct statement about the Calvin cycle. The Calvin cycle takes place primarily in the dark. The Calvin cycle has three phases: carbon fixation, reduction, and regeneration of RuBP. The basic function of the Calvin cycle is the conversion of solar energy to chemical energy.
The Calvin cycle has three phases: carbon fixation, reduction, and regeneration of RuBP.
In cellular respiration, a series of molecules forming an electron transport chain alternately accepts and then donates electrons. What is the advantage of such an electron transport chain? The advantage of an electron transport chain is the production of a large number of reduced, high-energy intermediates. The advantage of an electron transport chain is that a small amount of energy is released with the transfer of an electron between each pair of intermediates. The advantage of the respiratory electron transport chain is that oxygen is the final electron acceptor.
The advantage of an electron transport chain is that a small amount of energy is released with the transfer of an electron between each pair of intermediates.
Choose the best description of the cell cytoskeleton. The cell cytoskeleton is similar to an animal skeleton in providing rigid internal support and structure to the cell. The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components. The cell cytoskeleton serves as permanent scaffolding to anchor cell components into position within the cell cytoplasm.
The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components.
When a plant cell, such as one from a rose stem, is submerged in a very hypotonic solution, what is likely to occur? The cell will burst. The cell will become turgid. Plasmolysis will shrink the interior. The cell will become flaccid.
The cell will become turgid.
structural isomers
The figure above shows the structures of glucose and fructose. These two molecules are _____. cis-trans isomers enantiomers isotopes structural isomers
Which of the following statements about feedback regulation of a metabolic pathway is correct? The enzyme that is regulated by feedback inhibition is usually the last enzyme in the metabolic pathway. The products of the pathway become the reactants for a different reaction, and thus products are unable to accumulate. The final product of a metabolic pathway is usually the compound that regulates the pathway. Accumulation of the product of the pathway increases further formation of that product. The compound that regulates the pathway acts as a competitive inhibitor or a positive allosteric regulator.
The final product of a metabolic pathway is usually the compound that regulates the pathway.
b
The following question are based on the reaction A + B ↔ C + D shown in the accompanying figure. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in the figure? a b c d
d
The following question are based on the reaction A + B ↔ C + D shown in the accompanying figure. Which of the following in the figure would be the same in either an enzyme-catalyzed or a noncatalyzed reaction? a b c d
Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER). The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes. Smooth ER is part of the endomembrane system of the eukaryotic cell, and rough ER is not. Rough ER consists of a network of membranous tubules and sacs called cisternae, whereas smooth ER is less complex.
The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.
What is true of all cancers? They are inherited. They are caused by chemical carcinogens. They have escaped normal cell cycle controls.
They have escaped normal cell cycle controls.
In facilitated diffusion, what is the role of the transport protein? Transport proteins organize the phospholipids to allow the solute to cross the membrane. Transport proteins provide the energy for diffusion of the solute. Transport proteins provide a low-resistance channel for water molecules to cross the membrane. Transport proteins provide a protein site for ATP hydrolysis, which facilitates the movement of a solute across a membrane. Transport proteins provide a hydrophilic route for the solute to cross the membrane.
Transport proteins provide a hydrophilic route for the solute to cross the membrane.
B
Which molecule shown above has a carbonyl functional group in the form of an aldehyde? A B C D
The oxygen consumed during cellular respiration is involved directly in which process or event? the oxidation of pyruvate to acetyl CoA accepting electrons at the end of the electron transport chain glycolysis the citric acid cycle
accepting electrons at the end of the electron transport chain
Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate? oxaloacetate citrate glyceraldehyde 3-phosphate acetyl CoA
acetyl CoA
Which of the following types of reactions would decrease the entropy within a cell? catabolic reactions digestion anabolic reactions hydrolysis
anabolic reactions
Plant cell walls consist mainly of _____. chlorophyll cellulose chitin peptidoglycan None of the choices is correct.
cellulose
A noncompetitive inhibitor decreases the rate of an enzyme reaction by _____. changing the shape of the enzyme's active site changing the free energy change of the reaction binding at the active site of the enzyme acting as a coenzyme for the reaction
changing the shape of the enzyme's active site
Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? free ribosomes and ribosomes attached to the ER cellulose fibers in the cell wall membrane proteins of the inner nuclear envelope components of the cytoskeleton
components of the cytoskeleton
Singer and Nicolson's fluid mosaic model of the membrane proposed that membranes_____. consist of protein molecules embedded in a fluid bilayer of phospholipids are a single layer of phospholipids and proteins are a phospholipid bilayer between two layers of hydrophilic proteins consist of a mosaic of polysaccharides and proteins
consist of protein molecules embedded in a fluid bilayer of phospholipids
The movement of glucose into a cell against a concentration gradient is most likely to be accomplished by which of the following? facilitated diffusion of the glucose using a carrier protein passive diffusion of the glucose through the lipid bilayer movement of glucose into the cell through a glucose channel cotransport of the glucose with a proton or sodium ion that was pumped across the membrane using the energy of ATP hydrolysis receptor-mediated endocytosis
cotransport of the glucose with a proton or sodium ion that was pumped across the membrane using the energy of ATP hydrolysis
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the _____. creation of a proton-motive force formation of ATP reduction of NAD+ lowering of pH in the mitochondrial matrix
creation of a proton-motive force
A chemical reaction that has a positive ΔG is best described as _____. exergonic spontaneous endergonic enthalpic
endergonic
The evolution of eukaryotic cells most likely involved _____. an endosymbiotic fungal cell evolving into the nucleus endosymbiosis of an aerobic bacterium in a larger host cellthe endosymbiont evolved into mitochondria acquisition of an endomembrane system and subsequent evolution of mitochondria from a portion of the Golgi anaerobic archaea taking up residence inside a larger bacterial host cell to escape toxic oxygenthe anaerobic bacterium evolved into chloroplasts
endosymbiosis of an aerobic bacterium in a larger host cellthe endosymbiont evolved into mitochondria
Which of the following contain the 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules? motile cilia and primary (nonmotile) cilia flagella and motile cilia basal bodies and primary (nonmotile) cilia centrioles and basal bodies
flagella and motile cilia
Carbohydrates and fats are considered high-energy foods because they _____. are easily reduced. have a lot of electrons associated with hydrogen. have a lot of oxygen atoms. have no nitrogen in their makeup.
have a lot of electrons associated with hydrogen.
Humans can digest starch but not cellulose because _____. humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose the monomer of starch is glucose, while the monomer of cellulose is galactose the monomer of starch is fructose, while the monomer of cellulose is glucose starch monomers are joined by covalent bonds and cellulose monomers are joined by ionic bonds
humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose
Diffusion _____. is a passive process in which molecules move from a region of higher concentration to a region of lower concentration is very rapid over long distances requires an expenditure of energy by the cell requires integral proteins in the cell membrane
is a passive process in which molecules move from a region of higher concentration to a region of lower concentration
Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells? mitochondrial outer membrane mitochondrial inner membrane mitochondrial matrix mitochondrial intermembrane space
mitochondrial intermembrane space
Which organelle is the primary site of ATP synthesis in eukaryotic cells? Golgi apparatus lysosome peroxisome mitochondrion
mitochondrion
The building blocks or monomers of nucleic acid molecules are called _____. fatty acids polysaccharides pyrimidines and purines DNA and RNA nucleotides
nucleotides
The four main categories of large biological molecules present in living systems are _____. proteins, nucleic acids, carbohydrates, and lipids monosaccharides, lipids, polysaccharides, and proteins proteins, DNA, RNA, and steroids nucleic acids, carbohydrates, monosaccharides, and proteins RNA, DNA, proteins, and carbohydrates
proteins, nucleic acids, carbohydrates, and lipids
In mitochondria, exergonic redox reactions provide the energy that establishes the proton gradient. are coupled via phosphorylated intermediates to ender-gonic processes. are the source of energy driving prokaryotic ATP synthesis. reduce carbon atoms to carbon dioxide. are directly coupled to substrate-level phosphorylation.
provide the energy that establishes the proton gradient.
Which of the following does not occur during the Calvin cycle? consumption of ATP regeneration of the CO2 acceptor release of oxygen carbon fixation oxidation of NADPH
release of oxygen
Which process is most directly driven by light energy? reduction of NADP+ molecules creation of a pH gradient by pumping protons across the thylakoid membrane ATP synthesis carbon fixation in the stroma removal of electrons from chlorophyll molecules
removal of electrons from chlorophyll molecules
The chemical reaction illustrated in the accompanying figure _____. is a hydrolysis reaction joins two fatty acids together results in a peptide bond links two polymers to form a monomer
results in a peptide bond
Which level of protein structure do the α-helix and the β-pleated sheet represent? primary secondary tertiary quaternary
secondary
The force driving simple diffusion is _____, while the energy source for active transport is _____. the concentration gradient; ATP phosphorylated protein carriers; ATP the concentration gradient; ADP transmembrane pumps; electron transport
the concentration gradient; ATP
In a bacterium, we will find DNA in _____. a membrane-enclosed nucleus the nucleoid ribosomes mitochondria
the nucleoid
The tertiary structure of a protein is the _____. overall protein structure resulting from the aggregation of two or more polypeptide subunits order in which amino acids are joined in a polypeptide chain organization of a polypeptide chain into an α-helix or β-pleated sheet unique three-dimensional shape of the fully folded polypeptide
unique three-dimensional shape of the fully folded polypeptide
