Bio 215 Mastering Biology
Matter and energy flow through the biosphere. The flow of matter, however, differs from the flow of energy. Which of the following statements accurately describes these differences? A) Matter flows in cycles, whereas energy flows in one direction. B) Matter and energy flow sometimes in cycles and sometimes unidirectionally. C) Energy flows as organic molecules are reduced to inorganic molecules, but matter does not. D) Matter does not accompany energy as it enters the biosphere, but it does flow with energy from the biosphere. E) Energy flows from chemotrophs to phototrophs, whereas matter flows from phototrophs to chemotrophs.
A
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? A) dehydration B) anabolism C) metabolism D) catabolism E) catalysis
D
At amino acid (aa) 1400: Normal: 5'- GAG GAG - 3' --> Mutant: 5'-AAG GAG - 3' Normal:Glu Glu --> Mutant: Glu Glu Normal: Leu Leu --> Mutant: Leu Val Normal: Leu Leu --> Mutant: Leu Leu Normal: Glu Glu --> Mutant: Lys Glu
D
Based on the kinetic data from the enzyme kinetics worksheet, which type of inhibitor is phenythiourea (PTU)? competitive non-competitive allosteric Both B and C None of the above. PTU is actually an activator
D
From the equation ΔG = ΔH − TΔS, it can be concluded that __________. A) the capacity of a system to perform useful work is related to the total free energy of the system B) increasing the temperature of a system will increase the probability of spontaneous change C) increasing the change in entropy of a system will increase the probability of spontaneous change D) all of the other answer choices are true
D
When plotting kinetic data, which of the following plots velocity against [S]? A) Haywood & Sons plot B) Schleiden-Schwann plot C ) Eadie-Hofstee plot D) Michaelis-Menten plot E) Lineweaver-Burk plot
D
Which of the following produces and modifies polysaccharides that will be secreted? peroxisome vacuole mitochondria Golgi lysosome
D
Which of these are by-products of cellular respiration? carbon dioxide and water ATP and carbon dioxide ATP, carbon dioxide, and water heat, carbon dioxide, and water glucose, carbon dioxide, and water
D
What functional group is commonly used in cells to transfer energy from one organic molecule to another? sulfhydryl carboxyl hydroxyl phosphate amino
D
A chemical reaction that has a positive ΔG is best described as A)endergonic. B) exergonic. C) spontaneous. D) entropic E) enthalpic
A
A primary objective of cell fractionation is to A) separate the major organelles so that their particular functions can be determined. B)separate lipid-soluble from water-soluble molecules. C) determine the size of various organelles. D) sort cells based on their size and weight. E) view the structure of cell membranes.
A
A scientist encounters an unknown culture of cells in a laboratory. The only tools available to the scientist to determine the type of cell (animal, prokaryotic, fungal, plant, etc.) are enzymes that degrade particular elements of the extracellular matrix of cells of particular types. Which of the following data would indicate that the unknown cells were from an animal source? A) The cells are disrupted by application of collagenase (an enzyme that degrades collagen). B) The cells are disrupted by application of lysozyme (an enzyme that degrades peptidoglycan). C) The cells are disrupted by application of cellulase (an enzyme that degrades cellulose). D) The cells are disrupted by application of a lipase (an enzyme that degrades lipids).
A
As molecules (e.g. proteins) move through the endomembrane system via vesicles, anything originally present in the lumen of the ER will be facing the _________ side of the plasma membrane after that vesicle fuses to the PM . extracellular cytoplasmic
A
Based on the kinetic data from the enzyme kinetics worksheet, which type of inhibitor is PHBA? competitive non-competitive allosteric Both B and C None of the above. PHBA is actually an activator
A
Based on the reaction it catalyzes (shown on page 1 of the enzyme kinetic worksheet), diphenol oxidase would be categorized as which type of enzyme? oxidoreductase transferase hydrolase ligase isomerase
A
Chemical energy is a form of _____ energy. potential kinetic entropic motion heat
A
During synthesis of the CFTR protein at the RER, the N-terminus was originally extending into the _________. cytoplasm extracellular space lumen of the RER
A
How do cells use the ATP cycle shown in the figure? Cells use the cycle to recycle ADP and phosphate. Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis. Cells use the cycle to recycle energy released by ATP hydrolysis. Cells use the cycle primarily to generate heat. Cells use the cycle to generate or consume water molecules as needed.
A
Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components. Which of the following organelles contains these hydrolytic enzymes in animal cells? lysosome glyoxysome central vacuole chloroplast peroxisome
A
If a protein is denatured, what level of protein structure would remain intact? primary secondary tertiary quaternary None of the above
A
The Michaelis-Menten plot is also known as the ___________. direct plot double-reciprocal plot lineweaver-burk plot eadie-hoffstee plot
A
The overall goal of the investigation involving diphenol oxidase was to identify a molecule that could ___________. slow fruit browning speed fruit ripening speed wound-healing slow fruit ripening None of the above
A
The size range of most plant and animal cells is ________. A)10-100 μm B) 50-100 mm C) 0.1-0.5 mm D) 1-10 nm 1-5 μm
A
True or False?: A system at chemical equilibrium can do no work. A) True B) False
A
When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell? It may be used to phosphorylate other molecules, like ADP or certain proteins. It is added to water and excreted as a liquid. It is secreted as waste. It enters the nucleus and affects gene expression. It is used ONLY to regenerate more ATP.
A
Which is NOT true of phototrophs? A) They cannot function as autotrophs. B) They capture light energy. C) They provide energy, in the form of organic carbon, for chemotrophs. D) They can be bacteria. E) They store energy as glucose, in the form of starch.
A
Which monomers make up RNA? A) Nucleotides B) Amino acids C) Simple sugars D) Polymers
A
Which of the following is (are) true for anabolic pathways? A) They consume energy to build up polymers from monomers. B) They are usually highly spontaneous chemical reactions. C) They consume energy to decrease the entropy of the organism and its environment. D) They release energy as they degrade polymers to monomers. E) They do not depend on energy transfer
A
Which of the following is a statement of the first law of thermodynamics? A) Energy cannot be created or destroyed. B) The entropy of the universe is decreasing. C) Energy cannot be transferred or transformed. D) The entropy of the universe is constant. E) Kinetic energy is stored energy that results from the specific arrangement of matter
A
Which of the following produces and modifies polysaccharides that will be secreted? A) Golgi B) mitochondria C) lysosome D) peroxisome E) vacuole
A
Which of the following statements about the formation of polypeptides from amino acids is true? A) A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. B) Polypeptides form by condensation or hydrolysis reactions. C) The reaction occurs through the addition of a water molecule to the amino acids. D) A bond can form between any carbon and nitrogen atom in the two amino acids being joined.
A
Which of these is exhibiting kinetic energy? a space station orbiting Earth an archer with a flexed bow a rock on a mountain ledge the high-energy phosphate bonds of a molecule of ATP a person sitting on a couch while watching TV
A
A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't often hydrolyze ATP unless they are simultaneously transporting ions. Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using ATP-powered calcium pumps. For example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a resting muscle cell's cytosol has a free calcium ion concentration of 10-7 while the concentration in the SR is 10-2, then how is the ATPase acting? ATPase activity must be routing calcium ions from the SR to the cytosol, and then to the cell's environment. ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. ATPase activity must be transferring i to the SR to enable this to occur. ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient. ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR.
B
In order to measure the rate of the reaction catlyzed by diphenol oxidase, what is being measured in this activity? the appearance of hydroquinone the appearance of para-benzoquinone the disappearance of para-benzoquinone the disappearance of hydroquinone
B
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? glycogen proteins nucleic acids lipids cellulose
B
Regarding the enzyme kinetics worksheet, which molecule is the substrate for diphenol oxidase? (assume a conventional reading of the reaction) PHBA hydroquinone phenylthiourea para-benzoquinone
B
The Lineweaver-Burk plot can also be described as the___. A) direct plot B) double-reciprocal plot C) hyperbolic plot D) v/[S] vs. v plot E) None of the above.
B
The bonds of a molecule (e.g. fructose) is an example of __________ energy. A) concentration gradient B) potential C) gravitational D) electrical E) kinetic
B
True or False?: Heterotrophs can convert inorganic carbon into organic carbon. A) True B) False
B
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule? anabolism hydrolysis entropic dehydration decomposition dehydration synthesis
B
Which complex carbohydrate contains only a-1,4-glycosidic linkages? A) Glycogen B) Amylose C)Amylopectin D) Cellulose
B
Which measurement is used most frequently when measuring whole cells? decimeter micrometer picometer meter nanometer
B
Which molecule is not a carbohydrate? A) Glycogen B) Lipid C) Starch D) Cellulose
B
Which of the following complex carbohydrates is listed with its correct function? A) Amylose: main component of plant starch B) Cellulose: structural component of plant cell walls C) Starch: primary energy-storage molecule in animals D) Chitin: constituent of bacterial cell walls
B
Which of the following metabolic processes can occur without a net influx of energy from some other process? glucose + fructose →sucrose C6H12O6+ 6 O2→6 CO2+ 6 H2O amino acids →protein ADP + P i →ATP + H2O 6CO2+ 6H2O→C6H12O6+ 6 O2
B
Which of the following statements is true concerning catabolic pathways? A) They are nonspontaneous. B) They supply energy, primarily in the form of ATP, for the cell's work. C) They are endergonic. D) They combine molecules into more energy-rich molecules. E) They build up complex molecules such as protein from simpler compounds
B
Which polysaccharide contains a modified monosaccharide? A) Starch B) Peptidoglycan C) Cellulose D) Glycogen
B
Why is ATP an important molecule in metabolism? The opposite charges on the phosphate groups attract them to one another, generating a stable molecule. It provides energy coupling between exergonic and endergonic reactions. It is one of the four building blocks for DNA synthesis. Its terminal phosphate group contains a strong ionic bond that, when hydrolyzed, releases free energy. Its hydrolysis provides an input of free energy for exergonic reactions.
B
A particular plasma membrane protein spans the membrane one time, has an N-terminus that is cytoplasmically localized and its C-terminus localized to the extracellular space. Which import pathway was involved in synthesizing this protein? transgressional poly-translational co-translational transcriptional post-translational
C
Aerobic refers to what property of chemotrophs? A) Fermentation releases great amounts of gas but only in chemotrophs. B) Chemotroph metabolism that does not require oxygen. C) Chemotrophs require oxygen to convert energy into a usable form. D) Heat losses occur in the presence of oxygen. E) Chemotrophs remove carbon dioxide from the air
C
Based on the lineweaver-burke plot of the kinetic data from the enzyme kinetics worksheet, which reaction had the greatest Vmax? (Note: assume values if there is a difference of +/- 0.02) PHBA both the control reaction and the PTU reaction both the control reaction and the PHBA reaction phenylthiourea enzyme alone (control)
C
Based on the lineweaver-burke plot of the kinetic data from the enzyme kinetics worksheet, which reaction had the smallest Km? (Note: assume equal values if there is a difference of +/- 0.02) Both control and PHBA PHBA Both control and PTU
C
In a given chemical reaction, if the reactants contain more free energy compared to the products, the reaction will be... A) endergonic B) at equilibrium C) exergonic
C
In the enzyme kinetics worksheet, what is used as a measure of the reaction rate? substrate concentration enzyme concentration optical density
C
In the reaction catalyzed by diphenol oxidase (shown on page 1 of the enzyme kinetic worksheet), hydroquinone is __________ to form para-benzoquinone. hydrogenated reduced oxidized hydroxylated hydrolyzed
C
Most cells cannot harness heat to perform work because cells do not have much heat; they are relatively cool. heat is not a form of energy. temperature is usually uniform throughout a cell. heat must remain constant during work. heat can never be used to do work
C
Part A Which polymers are composed of amino acids? A) Carbohydrates B) Monomers C) Proteins D) Nucleic acids
C
Select the correct statement about chemical energy, a term used by biologists to refer to potential energy available for release in a chemical reaction. A photosynthetic cell within a plant leaf produces chemical energy, stored within glucose molecules. When a glucose molecule is catabolized to CO2 and H2O, chemical energy is lost. Light energy is converted to chemical energy during photosynthesis
C
The CFTR protein underwent____________ import. proteolytic post-transcriptional co-translational post-translational transcriptional
C
What sort of change would occur in the above mutant? a nonpolar aa was replaced with a polar aa a polar uncharged aa was replaced with a basic aa an acidic aa was replaced with a basic amino aa a polar aa was replaced with a non-polar aa a basic aa was replaced with an acidic aa
C
Which of the following statements about ATP (adenosine triphosphate) is correct? The hydrolysis of ATP is an endergonic process. Almost all of the free energy released on the hydrolysis of ATP is released as heat. The cycling between ATP and ADP + Pi provides an energy coupling between catabolic and anabolic pathways. The hydrolysis of ATP can supply energy needed for catabolic pathways. None of the above are correct.
C
Which of the following statements about equilibrium of chemical reactions is correct? Reactions can only go in the direction toward equilibrium. The equilibrium point is where the system has the highest free energy A reaction that is at equilibrium is not capable of doing any work. Most reactions in a living cell are close to equilibrium. The equilibrium point of a reaction represents the least stable configuration for that reaction
C
Which of the following statements about monosaccharide structure is true? A) All monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms. B) Aldoses and ketoses differ in the position of their hydroxyl groups. C) Monosaccharides can be classified according to the spatial arrangement of their atoms. D) A six-carbon sugar is called a pentose
C
Which of the following statements concerning cells of bacteria and archaea is correct? A) DNA is present in the mitochondria of both bacteria and archaea B) Archaea contain a membrane-bound nucleus; bacteria do not. C) DNA is present in both archaea and bacteria. D)Archaea contain small membrane-enclosed organelles; bacteria do not.
C
Which organelle often takes up much of the volume of a plant cell? lysosome mitochondria vacuole peroxisome Golgi
C
Which part of the adenosine triphosphate molecule is released when it is hydrolyzed to provide energy for biological reactions? α-phosphate (the phosphate closest to ribose) β-phosphate (the middle phosphate) γ-phosphate (the terminal phosphate) adenine group ribose sugar
C
Which statement correctly describes the nuclear envelope? A) The outer layer of the nuclear envelope is coated with the nuclear lamin. B) The nuclear envelope is a single membrane, consisting of a phospholipid bilayer. C) The nuclear envelope is continuous with the endoplasmic reticulum. D) All of the proteins of the cell are synthesized on ribosomes bound on the nuclear envelope. E) Plasmadesmosomes in the nuclear envelope permit the exchange of macromolecules between the nucleus and the cytoplasm.
C
"Conservation of energy" refers to the fact that _____. no chemical reaction is 100 percent efficient if you conserve energy you will not be as tired the net amount of disorder is always increasing energy cannot be created or destroyed but can be converted from one form to another the entropy of the universe is always increasing
D
In a biochemical reaction, reactants may be converted into products. The extent to which this occurs spontaneously is expressed as which of the following? A) Keq B) TΔS C) ΔS D) ΔG E) temperature
D
In a given 'system' (e.g. a chemical reaction taking place inside of a cell), the amount of energy available to do work is called _____________. A) acctivation energy B) entropy C) heat D) free energy E) thermodynamics
D
In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is A) the relative solubility of the component. B) the presence or absence of nucleic acids in the component. C)the presence or absence of lipids in the component. D)the size and weight of the component. E) the percentage of carbohydrates in the component.
D
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP? anabolism digestion redox cellular respiration potentiation
D
One of the key innovations in the evolution of eukaryotes from a prokaryotic ancestor is the endomembrane system. What eukaryotic organelles or features might have evolved as a part of, or as an elaboration of, the endomembrane system? A) plasma membrane B) mitochondria C) chloroplasts D) nuclear envelope E) none of these
D
Protists and bacteria are grouped into different domains because A) None of the above. Protists and bacteria are classified in the same domain. B) protists eat bacteria C)bacteria are not made of cells D) protists have a membrane-bound nucleus, which bacterial cells lack. E) protists are a distinct grouping of prokaryotic cells distantly-related to bacteria
D
The mathematical expression for the change in free energy of a system is ΔG =ΔH - TΔS. A)Which of the following is (are) correct? B) ΔS is the change in enthalpy, a measure of randomness. C) T is the temperature in degrees Celsius. D) ΔG is the change in free energy. E) ΔH is the change in entropy, the energy available to do work
D
The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water, is an example of _____. an endergonic pathway a pathway that converts organic matter into energy a pathway in which the entropy of the system decreases a catabolic pathway a pathway that occurs in animal cells but not plant cells
D
Energy is important to life forms because A) all life forms require a continuous supply of it. B) it is required to make specific alterations in the cell. C) it is required to do work. D) all life forms require a continuous supply of it; it is required to make specific alterations in the cell. E) all life forms require a continuous supply of it; it is required to make specific alterations in the cell; it is required to do work.
E
Energy is observed in two basic forms: potential and kinetic. Which of the following correctly matches these forms with a source of energy? A) the energy associated with a gradient of ions across a membrane: kinetic energy B) the heat released from a living organism: potential energy C) the motion of individual molecules: potential energy D) the energy related to the height of a bird above the ground: kinetic energy E) the covalent bonds of a sugar molecule: potential energy
E
In accordance with the 2nd law of thermodynamics, whenever energy is transformed, there is always an increase in the A)entropy of the system. B) enthalpy of the universe. C)free energy of the system. D) free energy of the universe. E) entropy of the universe
E
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? saturation of the enzyme activity insufficient cofactors allosteric inhibition denaturation of the enzyme competitive inhibition
E
On average, prokaryotic cells range in size from ___________. 1 - 5 nm 10 - 100 nm 0.1 - 1 um 10 - 100 um 1 - 5 um
E
Prokaryotes are classified as belonging to two different domains. What are the domains? A) Bacteria and Fungi B) Archaea and Protista C) Bacteria and Eukarya D) Bacteria and Protista E) Bacteria and Archaea
E
The statement, "Energy is neither created nor destroyed," describes A) the first law of thermodynamics. B) enthalpy. C) the law of conservation of energy. D) the second law of thermodynamics. E) the first law of thermodynamics; the law of conservation of energy.
E
What is the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in RNA? A) The sugar molecule is different. B) The nitrogen-containing base is different. C) The number of phosphates is three instead of two. D) The number of phosphates is three instead of one. E) There is no difference
E
What type of reactions are use to break down proteins in cells? condensation hydrogenation denaturation dehydration hydrolysis
E
When plotting the kinetic data on the enzyme kinetics worksheet,based on the direct plot, which reaction had the greatest Vmax? enzyme + PHBA enzyme + phenythiourea both control and enzyme + PHBA both control and enzyme + phenythiourea the enzyme alone (control)
E
Which of the following best describes enthalpy (H)? A) the total kinetic energy of a system B) the cell's energy equilibrium C) the system's entropy D) the condition of a cell that is not able to react E) the heat content of a system
E
Which of the following is true for all exergonic reactions? A) It is not spontaneous. B) The products have more total energy than the reactants. C) A net input of energy from the surroundings is required for the reactions to proceed. D) The reactions are rapid. E) The reaction proceeds with a net release of free energy
E
Which of the following statements about the combustion of glucose with oxygen to form water and carbon dioxide (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O) is correct? The reverse reaction, making glucose from water and carbon dioxide, must be an exergonic reaction. The entropy of the universe decreases as the result of this reaction. This is the process of cellular respiration, an anabolic pathway that releases free energy. The free energy lost in this combustion is less than the energy that appears as heat. The entropy of the products is greater than the entropy of the reactants.
E
You wish to obtain a pure mitochondria sample from lysed cells. The best way to obtain this sample would be A) SDS-PAGE B) chromatography and polyacrylamide gel electrophoresis. C) agarose gel electrophoresis D) chromatography. E) centrifugation.
E
Prokaryotes have :
Nucleoid
which prtoeins are synthesized by bound ribosomes
insulin, lysosomal enzyme, er protein
Eukaryotes have:
lysosome, mitochondria, nucleolus
lysosomes
macromolecule digestion autophagy
smooth er function(s)
poison detoxification lipid synthesis calcium ion storage
Golgi apparatus function(s)
protein modification and sorting cisternal maturation
rough er function(s)
protein synthesis
both:
ribosomes, flagella, plasma membrane
True or false? Peptidoglycan is a polysaccharide found only in bacteria. True False
true