BIOC385: Exam 1 Questions
Choose the one statement below that most accurately describes the biochemical basis for the emergence of MRSA infections. A variant transpeptidase enzyme in Staph aureus that does not bind methicillin. Penicillin and methicillin are structurally similar, which causes antibiotic resistance. Staph aureus express high levels of beta-lactamase. Staph aureus exports methicillin faster than it can inhibit the transpeptidase.
A variant transpeptidase enzyme in Staph aureus that does not bind methicillin.
The product Beano contains ____ which helps humans digest raffinose-series oligosaccharides. B-galactosidase Lactase A-galactosidase Amylase
A-galactosidase
Given the same carbohydrate linkages, what are the three main differences between amylopectin and glycogen? A. Branching is more frequent in glycogen than in amylopectin, occurring every 8-12 glucose residues instead of every 15-30. B. Glycogen has a dimeric protein at the reducing end, whereas amylopectin has a single glucose residue. C. Amylopectin is found in plants, and glycogen is found in animalitos s. D. Glycogen contains numerous sulfate-modified glucose residues, whereas amylopectin does not. E. N-acylation is more frequent in glycogen than in amylopectin.
A. Branching is more frequent in glycogen than in amylopectin, occurring every 8-12 glucose residues instead of every 15-30. B. Glycogen has a dimeric protein at the reducing end, whereas amylopectin has a single glucose residue. C. Amylopectin is found in plants, and glycogen is found in animalitos s.
In the five steps used by photosynthetic organisms to convert solar energy into chemical energy, which molecules store the solar energy before sugar synthesis? ATP and NADPH Chlorophylls NADH and FADH2 O2 and H20
ATP and NADPH
The example of water freezing into ice is an example of _______________. Decrease in entropy of the system. An increase in entropy of the system A decrease in the entropy of the surroundings. No change in the entropy of the system.
Decrease in entropy of the system
Insulin activates phosphofructokinase 2 (2PFK2). This leads to a(n) _____ in concentration of fructose 2, 6 bisphosphate, which favors the _____ pathway. Increase; gluconeogenesis Decrease; glycolysis Decrease; gluconeogenesis Increase; glycolysis
Increase; glycolysis
Under what condition(s) do the wasteful side reactions of O2 with rubisco become significant? At night Increased temperature and intense light Increased rubisco concentrations Higher levels of CO2 than O2
Increased temperature and intense light
R is the highly active form of an allosteric enzyme and T is the less active form of enzyme. What would happen to [T]/[R] if substrate concentration is decreased?
Increases
Paraquat is an effective herbicide that kills plants by disrupting the photosynthetic electron transport system. Why then was the spraying of marijuana fields with paraquat discontinued in the 1980s? It was discontinued because paraquat contaminated marijuana which was being imported into the US and was thought to cause lung damage It was known at the time that marijuana was resistant to paraquat so it was a waste of money It was stopped because the governments of the countries involved could not decide who should pay for it. It was discovered that aerial spraying of paraquat is very dangerous to livestock and should never be used for crop management because it inhibits PSI in cows.
It was discontinued because paraquat contaminated marijuana which was being imported into the US and was thought to cause lung damage
The Biosphere 2 project, in Tucson, Arizona, was an experiment involving a large sealed terrarium with humans and photosynthetic plants living in balance. Why did the project have to be interrupted after only a few months? Levels of CO2 rose to dangerous levels. The humans ran out of food. The rate of photosynthesis was too high. The plants stopped producing oxygen.
Levels of CO2 rose to dangerous levels.
The function of chloroplasts in plant cells is to convert ____________________. Heat energy to chemical energy. Chemical energy to heat energy. Heat energy to light energy Light energy to chemical energy.
Light energy to chemical energy.
Energy conversion in living systems is required for what three types of work? Osmotic work, chemical work, potential work Osmotic work, chemical work, mechanical work Kinetic work, chemical work, mechanical work Osmotic work, photosynthetic work, mechanical work
Osmotic work, chemical work, mechanical work
What group in photosystem II (PSII) directly reacts with H2O during its light-driven oxidation? Tyrosine Pheophytin P680 Oxygen evolving center
Oxygen evolving center
Electrons from plastocyanin are passed on to _______ Cytochrome b6f O2 P680+ P700+
P700+
What chemical process is able to take place in the presence of solar energy? hydrolysis Photosynthesis anaerobic respiration hydrogenation
Photosynthesis
The amino acid sequence of a protein determines its structure. Which of the following statements is true? Two proteins with nearly identical amino acid sequences should have very similar protein structures.
Two proteins with nearly identical amino acid sequences should have very similar protein structures.
Which of the following oligosaccharides are found in high abundance in some types of vegetables and have been known to cause intestinal distress? Amylose lacto-N-tetraose Amylopectin Verbascose
Verbascose
If the equilibrium constant (Keq) is greater than 1, which direction will the reaction proceed? Not enough information is given to determine the direction of reaction. neither direction Spontaneously to products Spontaneously to reactants
Spontaneously to products
The O2 generated from photosynthesis is derived from? CO2 reduction to glycerate-3-phosphate Water molecules that directly reduce PSI* Water molecules that directly reduce PSII*. CO2 reduction to glyceraldehyde-3-phosphate.
Water molecules that directly reduce PSII*.
Which of the following best defines the first law of thermodynamics? Total amount of energy in the universe is constant. There is no entropy at zero Kelvin. Entropy is a measure of disorder. All spontaneous processes in the universe tend toward dispersal of energy.
Total amount of energy in the universe is constant
Which enzyme below is required in the nonoxidative phase of the pentose phosphate pathway allows to convert ribose-5-phosphate and xylulose-5-phosphate into glyceraldehyde-3-phosphate and sedoheptulose-7-phosphate? Hydrolase Kinase Transketolase Isomerase
Transketolase
Which enzyme does penicillin target in bacteria? Beta-lactamase Peptidase Transpeptidase Alpha-galactosidase
Transpeptidase
Which chromophore appears orange and absorbs in the blue range of the visible spectrum? Phycocyanobilin B-carotene Chlorophyll Phycoerythrobillin
B-carotene
How many 32P-ATPs would be produced if 48 H+ were transported through the ATP synthase complex in the thylakoid membrane? Choose one: A. 16 B. 12 C. 8 D. 6
B. 12
The three stages of the Calvin cycle are__________________.
(1) fix CO2, (2) use NADPH and ATP, and (3) regenerate the starting C5molecule.
2-phosphoglycerate(2PG) is converted to phosphoenolpyruvate (PEP) by the enzyme enolase. The standard free energy change(delta Go') for this reaction is +1.7 kJ/mol. If the cellular concentrations are 2PG = 0.5 mM and PEP = 0.1 mM, what is the free energy change at 37 oC for the reaction 2PG ← → PEP? -2.4 kJ/mol +2.4 kJ/mol -4146.4 kJ/mol 5.8 kJ/mol -5.8 kJ/mol
-2.4 kJ/mol
If one homozygous parent expresses the GTA glycosyltransferase and the other homozygous parent expresses the GTB glycosyltransferase, what is the probability of a child with a blood type of AB? 25% 75% 0% 100%
100%
The products of the oxidative portion of the pentose phosphate pathway are carbon dioxide and_____________________.- 2 NADH + 1 hexose phosphate. 2 NADPH + 1 pentose phosphate. 2 NADPH + 1 hexose phosphate. 2 NADP+ + 1 pentose phosphate.
2 NADPH + 1 pentose phosphate.
If one heterozygous parent expresses the GTA glycosyltransferase and the other heterozygous parent expresses the GTB glycosyltransferase, what is the probability of a child with a blood type of O? 0% 25% 75% 100%
25%
What is the maximum number of covalent bonds a carbon atom can make? 8 6 2 4
4
Pea aphids are photosynthetic insects. They synthesize carotene and can use light-absorbed energy to make ATP. Which wavelength of light optimizes ATP production in these insects? 435 nm 600 nm 550 nm
435 nm
Which two functional groups are involved in producing a peptide bond? Amino and carboxyl Alcohol and amino Methyl and amino SAmino and thiol
Amino and carboxyl
Which of the following statements is correct? Choose one: An exergonic reaction drives an endergonic reaction in living systems. C. ATP is rarely used in coupled reactions. D. The overall free energy of a coupled reaction is the difference of the free energies for the individual reactions.
An exergonic reaction drives an endergonic reaction in living systems.
What type of antigen(s) is/are expressed on the red blood cell of a person with type A blood? Neither antigen A or antigen B Antigen A Both antigen A and antigen B Antigen B
Antigen A
What is the underlying difference that determines blood type? A. The number of red blood cells produced determines blood type. B. Attachment of a monosaccharide determines blood type; whether the O antigen has a GalNAc attached, a Gal attached, both GalNAc and Gal attached, or neither attached. C. Whether or not N-acetyllactosamine disaccharide linked to glycoproteins or glycolipids is present on the surface of red blood cells. D. The ratio of glycoproteins to glycolipids in red blood cells determines blood type.
Attachment of a monosaccharide determines blood type; whether the O antigen has a GalNAc attached, a Gal attached, both GalNAc and Gal attached, or neither attached.
Which enzyme is produced by penicillin-resistant bacteria? Alpha-galactosidase Peptidase Transpeptidase Beta-lactamase
Beta-lactamase
The study of biochemistry attempts to explain_________________. The nature of life Biological processes at the molecular and cellular levels Physical processes at the macromolecular level Chemical processes at the atomic level
Biological processes at the molecular and cellular levels
Orange vegetables such as carrots and pumpkins are rich in β-carotene. They reflect orange light (and as a result appear orange to us), and absorb this color of light. Blue Red Green Yellow
Blue
If you wanted to maximize the growth of green, leafy plants, you might want to consider using lamps illuminating these colors. Blue and orange Blue and red Purple and green Red and green
Blue and orange
The ___ pathway is used by plants that thrive in high temperate conditions, such as sugarcane C3 C2 C4 CAM
C4
Which of the following is the correct formula for glucose? C6H12O6 C5H10O5 C6H10O6 C5H12O6
C6H12O6
Which statement below most accurately describes catabolic and anabolic pathways? Both types of pathways require ATP to facilitate metabolic flux. Both types of pathways require redox reactions to facilitate metabolic flux. Catabolic pathways synthesize new molecules and anabolic pathways degrade molecules. Catabolic pathways degrade molecules and anabolic pathways synthesize new molecules.
Catabolic pathways degrade molecules and anabolic pathways synthesize new molecules.
The primary difference between ATP synthesis during the photosynthetic light reactions and ATP synthesis in the mitochondrial electron transport chain is the Cellular location of the proton motive force. Number of NADPH required to produce ATP. Enzyme catalyzing the ATP synthesis. Number of ATP produced per 360° rotation of the F1 subunit of ATP synthase.
Cellular location of the proton motive force.
Which glycan is a major component of plant cell walls? Cellulose Glycogen Chitin Starch
Cellulose
Which of the following is responsible for transporting protons across the thylakoid membrane? A. Photosystem I B. Plastoquinone C. Cytochrome b6f D. Photosystem II
Cytochrome b6f
Select the TWO true statements from the list below regarding the structure and function of enzymes. The substrate can be predicted by simply knowing the structure of the unoccupied enzyme active site, similar to a key fitting a lock. All proteins are not enzymes but all enzymes are proteins. Enzymes decrease the equilibrium constant of biochemical reactions and increase the rates of reactions from years to minutes. Enzyme cofactors can increase the chemical functionality of enzymes, which are otherwise limited by the R groups of amino acids. Enzymes increase the rates of biochemical reactions without changing the equilibrium constant.
Enzyme cofactors can increase the chemical functionality of enzymes, which are otherwise limited by the R groups of amino acids. Enzymes increase the rates of biochemical reactions without changing the equilibrium constant.
If the Gibbs free energy change value for a reaction is less than zero, this reaction is _____. Exergonic. Endothermic. Exothermic. Endergonic.
Exergonic.
As shown below, some metabolic pathways use enzymes that are colocalized in membranes to facilitate reaction rates. Shared intermediates are used so effectively in these types of coupled reactions because they ________________. increase rates of product diffusion out of the active site. Allow products to diffuse through membrane to increase concentration Facilitate products being used as reactants without diffusing away Decrease the value of the mass action ratio Q Increase the value of change of Gdegrees`
Facilitate products being used as reactants without diffusing away
In the figure below, which state of matter has the highest entropy? Gas phase Solid phase Liquid phase All are equal entropy
Gas phase
Which of the following is an effect of high NADPH? A. Glucose-6-phosphate enters the pentose phosphate pathway. B. Glycolysis is reduced. C. Glucose-6-phosphate dehydrogenase is activated. D. Glucose-6-phosphate dehydrogenase is inhibited.
Glucose-6-phosphate dehydrogenase is inhibited.
Which glucose homopolymer would be used if a person had to sprint quickly? Starch Galactose Glycogen Sucrose
Glycogen
Which of the following is the MOST efficient storage form of glucose as an energy source? A. Amylopectin B. Cellulose C. Amylose D. Glycogen
Glycogen
Which FOUR statements below best describe differences between the glycolytic and gluconeogenic pathways. Gluconeogenesis is only found in liver and kidney cells, whereas glycolysis is only found in liver and pancreatic cells. Glycolytic enzymes are all found in the cytosol, whereas gluconeogenic enzymes are found in the cytosol and the mitochondrial matrix. Insulin stimulates flux through the glycolytic pathway, whereas glucagon stimulates flux through the gluconeogenic pathway. Citrate inhibits glycolysis but activates gluconeogenesis, whereas F-1,6-BP activates glycolysis and inhibits gluconeogenesis. Flux through glycolysis is activated by low energy charge in the cell, whereas flux through the gluconeogenic pathway is inhibited by high energy charge in the cell. Insulin inhibits flux through the gluconeogenic pathway, whereas glucagon inhibits flux through the glycolytic pathway. Three of the enzymes in glycolysis are reciprocally regulated by allosteric effectors that convert them into gluconeogenic enzymes, i.e., PFK-1 becomes PFK-2 and FBPase-1 becomes FBPase-2. This is not true of any enzymes in the gluconeogenic pathway. Gluconeogenesis generates glucose from non-carbohydrate sources, whereas glycolysis generates pyruvate from glucose.
Glycolytic enzymes are all found in the cytosol, whereas gluconeogenic enzymes are found in the cytosol and the mitochondrial matrix. Insulin stimulates flux through the glycolytic pathway, whereas glucagon stimulates flux through the gluconeogenic pathway. Insulin inhibits flux through the gluconeogenic pathway, whereas glucagon inhibits flux through the glycolytic pathway. Gluconeogenesis generates glucose from non-carbohydrate sources, whereas glycolysis generates pyruvate from glucose.
Which of the following equations represents the initial enzyme-catalyzed reaction in the Hatch-Slack pathway? Choose one: A. CO2 + oxaloacetate → malate B. HCO3- + phosphoenolpyruvate → oxaloacetate + Pi C. CO2 + phosphoenolpyruvate → malate + Pi D. CO2 + H2O → HCO3- + Pi
HCO3- + phosphoenolpyruvate → oxaloacetate + Pi
As a protein folds, what are the stabilizing forces that help keep the protein from spontaneously unfolding? Hydrophilic amino acids in the interior and hydrophobic amino acids on the exterior. A favorable change in free energy between the unfolded and folded states. Hydrophobic amino acids in the interior and hydrophilic amino acids on the exterior.
Hydrophobic amino acids in the interior and hydrophilic amino acids on the exterior.
Which of the following is a true representation of the experimental design and results? Choose one: A. ATP synthase was functioning in reverse. B. The proton-motive force dissipates in the presence of light. C. In order for ATP to be synthesized, the concentration of protons must be higher in the lumen than in the surrounding chloroplast solution. D. ATP was used as an energy source to pump protons from the lumen into the stroma.
In order for ATP to be synthesized, the concentration of protons must be higher in the lumen than in the surrounding chloroplast solution.
How can an energetically unfavorable reaction occur in a metabolic pathway? Increase the temperature inside the cell to make it a favorable reaction. Link it to an energetically favorable reaction. Energetically unfavorable reactions cannot occur in metabolic pathways. Link it to another energetically unfavorable reaction NADPH + 3 ATP 3 CO2 + 6 NADPH + 9 ATP + 6 H2O -> Glyceraldehyde-3-phosphate + 6 NADP+ + 9 ADP + 9 Pi O2 + 2 NADPH + 3 ATP -> H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 8 photons + NADP+ + 3 ATP-> 2 H2O + NADP+ + 3 ADP + 3 Pi
Link it to an energetically favorable reaction.NADPH + 3 ATP
The difference between an oxidation reaction and a reduction reaction is that oxidation is the ______ and reduction is the _____. Loss of protons; gain of protons Gain of protons; loss of electrons Loss of electrons; gain of electrons Gain of electrons; loss of electrons
Loss of electrons; gain of electrons
What is an advantage of using methicillin compared with penicillin? o Methicillin does not bind transpeptidase. o Penicillin does not bind transpeptidase as well as methicillin. o Penicillin is susceptible to inactivation by mutant transpeptidase enzymes. oMethicillin is resistant to beta-lactamase activity.
Methicillin is resistant to beta-lactamase activity.
What molecule activates the pentose phosphate pathway? ADP NADH NADP+ Ribulose-5-phosphate
NADP+
When NADPH/NADP+ ratios are high in chloroplasts, photophosphorylation via the cyclic e- pathway predominates. Select the ONE statement below that best describes the consequences of the shift to this pathway. O2 evolution decreases, and NADPH formation increases O2 evolution is unchanged, and NADPH formation decreases. O2 evolution increases, and NADPH formation decreases O2 evolution is unchanged, and NADPH formation increases. O2 evolution decreases and NADPH formation decreases.
O2 evolution decreases and NADPH formation decreases.
Experimental evidence based on measuring bond energies between DNA strands using all combinations of G, C, A, and T stacked bases demonstrates that the DNA double helix is stabilized by noncovalent interactions between nucleotides owing to __________ . Pi-pi stacking Hydrogen bonds Sigma bonds Ionic interactions
Pi-pi stacking
Heme and chlorophyll have similar overall structures. What is common between the two molecules? Color Hydrophobic tail Metal ion found at their center Polycyclic planar structure
Polycyclic planar structure
Amino acids are the building blocks for which biomolecules? Proteins Carbohydrates Micelles Nucleic acids
Proteins
Maximal activity of pyruvate carboxylase depends on which of the following substances? Choose the FOUR that apply. Oxaloacetate Pyruvate Biotin Bicarbonate [HCO3-] Thiamine pyrophosphate GTP Acetyl-Coenzyme A
Pyruvate Biotin Bicarbonate [HCO3-] Acetyl-Coenzyme A
Which of the following statements are true? Choose one or more: Glucose is a product of the catabolism of all major biomolecules. Pyruvate is a product of the catabolism of all major biomolecules. Ammonia is a product of the catabolism of all major biomolecules. Acetyl CoA is a product of the catabolism of all major biomolecules.
Pyruvate is a product of the catabolism of all major biomolecules. Acetyl CoA is a product of the catabolism of all major biomolecules.
Choose the ONE true statement referring to the following coupled reactions: Rxn1 A↔B DG°' = -2 kJ/mol Rxn2 B↔C DG°' = +7 kJ/mol Rxn3 C↔D DG°' = -8 kJ/mol Net Rxn A↔D DG°' = -3 kJ/mol The net reaction of A→D is unfavorable because the DG°' value is less than 0. Rxn1 is a favorable reaction and will proceed in cells even if cellular concentrations of reactants and products change. Rxn2 (B↔C) is unfavorable in the forward direction on its own, but if coupled to Rxn3 (C↔D), the overall conversion of B to D will occur. For Rxn2, if the DG°' value changes to +9 kJ/mol, the rate of the overall reaction A↔D will decrease.
Rxn2 (B↔C) is unfavorable in the forward direction on its own, but if coupled to Rxn3 (C↔D), the overall conversion of B to D will occur.
Which of the following strategies is used to control hexokinase activity when gluconeogenesis is active? A. Sequestering in different cellular compartments B. Allosteric regulation by fructose-2,6-BP C. Allosteric regulation by citrate D. Phosphorylation
Sequestering in different cellular compartments
Penicillin kills bacteria by inhibiting the biosynthesis of the cell wall. How does penicillin cause the inhibition? The carbonyl carbon of the b-lactam ring of penicillin binds to transpeptidase. The b-lactam ring in penicillin is hydrolyzed. The glycine in transpeptidase binds to penicillin. The transpeptidase of the bacteria binds to methicillin.
The carbonyl carbon of the b-lactam ring of penicillin binds to transpeptidase.
In a hydrogen bond between a water molecule and another water molecule _______. The hydrogen bond typically forms between the oxygen atom of the water and the hydrogen on the other water. A hydrogen on the water molecule forms a covalent bond to a hydrogen atom on the other water. A hydrogen ion on the water molecule forms an ionic bond with the oxygen ion on the other water. The hydrogen atom forms an ionic bond with a carbon on the other water.
The hydrogen bond typically forms between the oxygen atom of the water and the hydrogen on the other water.
Put the following steps in photosynthesis in the correct order to generate 2 NADPH and 3 ATP following the absorption of 8 photons and return of 12 H+ from the thylakoid space to the stroma.
The sun comes up. PSII absorbs 4 photons leading to photooxidation of 4 chlorophyll molecules and oxidation of 2 H2O to replace the 4 e- in chlorophyll and release 4 H+ into the thylakoid lumen. Oxidation of pheophytin initiates a series of redox reactions culminating in the reduction of 4 plastocyanin and translocation of 8 H+ across the thylakoid membrane. PSI absorbs 4 photons leading to the photooxidation of 4 plastocyanin an initiation of a series of redox reactions culminating in the reduction of 2 NADP+ to yield 2 NADPH. A total of 12 H+ enter the chloroplast ATP synthase to generate 3 ATP when they return to the stroma and induce conformational changes in the head piece of the complex.
The term greenhouse effect refers to the idea that _____. Tropical rainforests are gradually being eliminated The temperature of the earth is increasing because of heat trapped by gases such as CO2. The capacity of the earth's plant matter to store CO2 is increasing. The global production of plant matter is increasing.
The temperature of the earth is increasing because of heat trapped by gases such as CO2.
Which statement regarding CAM plants is true? They are more efficient than C4 plants They absorb CO2 at night and release it to the Calvin cycle during the day They use one cell type to absorb and store CO2 before utilizing it in the Calvin Cycle in another cell type They store CO2 in 3-phosphoglycerate before releasing it to the Calvin cycle
They absorb CO2 at night and release it to the Calvin cycle during the day
Photosynthetic organisms are essential to the efficient cycling of carbon on Earth. Which of the following statements correctly describes their role in this process? They are able to produce CO2 , which fuels animal metabolism. They are able to use energy from sunlight to fix atmospheric CO2 in the form of carbohydrates. They use energy from sunlight to power the decarbonation of atmospheric CO2 to form O2. They are able to use energy from sunlight to obtain carbon from detritus in the soil and fix it into carbohydrates.
They are able to use energy from sunlight to fix atmospheric CO2 in the form of carbohydrates.
Why is referring to the Calvin cycle reactions as the dark reactions a misnomer They require an active photosynthetic system in the light, so are not the "dark reactions" in everyday biochemistry They occur primarily at night They do not absorb sunlight energy
They require an active photosynthetic system in the light, so are not the "dark reactions" in everyday biochemistry
How would individuals with decreased levels of the pentose phosphate enzyme glucose-6-phosphate dehydrogenase respond to oxidative stress They would rapidly neutralize cellular levels of H2O2 and other reactive oxygen species. Higher than normal levels of NADPH would accumulate. They would compensate with higher than normal levels of pentose phosphate pathway activity. They would not have the ability to regenerate reduced glutathione as rapidly.
They would not have the ability to regenerate reduced glutathione as rapidly
During photophosphorylation, the protons are pumped into the _________, and the ATP is made in the ________ Stroma; thylakoid lumen Cytoplasm; stroma Thylakoid lumen; stroma Thylakoid lumen; cytoplasm
Thylakoid lumen; stroma
In the 1770s, Joseph Priestly showed that animal respiration could be supported in a closed, airtight container by plants, because the plants would produce oxygen. A modern version of this experiment was conducted in the 1990s with Biosphere 2 in Tucson, Arizona, but needed to be terminated for the safety of the inhabitants; it was the hope that a similar habitat could support human life on other planets such as Mars. What problem would need to be solved before a Biosphere habitat could support life on another planet for years, if not decades? We need to improve the efficiency of CO2 removal from the atmosphere within the airtight habitat. We need to improve the greenhouse effect to prevent overheating of the airtight habitat. We need to improve the availability of water such that photosynthesis can occur more efficiently in plants, and humans can cool off. We need to improve the removal of nitrogen from the soil.
We need to improve the efficiency of CO2 removal from the atmosphere within the airtight habitat.
A hydrogen bond can best be described as a ________________. Strong ionic interaction. Weak covalent interaction. Strong covalent interaction. Weak noncovalent interaction.
Weak noncovalent interaction.
Resonance energy transfer from one chlorophyll in the photosystems results in______________. a neighboring chlorophyll in an excited state. The release of a photon heat release a reduced neighboring pheophytin molecule
a neighboring chlorophyll in an excited state.
Both methicillin and penicillin are unable to inhibit alpha-galactosidase. Beta-lactamase. a variant transpeptidase
a variant transpeptidase
In the __________ of rubisco by __________, a mechanism is used to control the activity of the Calvin cycle in response to light. Choose one: A. activation; decreased Mg2+ B. inhibition; thioredoxin C. activation; increased pH D. activation; CA1P
activation; increased pH
The five-step mechanism of ribulose bisphosphate carboxylase (rubisco)_________________. adds a CO2 molecule to a C5 ribulose sugar, yielding an unstable C6 molecule that cleaves into two C3 molecules. involves the incorporation of 3 CO2 molecules to yield one 3-phosphoglycerate molecule. involves C1, C3, C4, C5, and C6 molecules in the enzyme mechanism intermediates. is an overall thermodynamically unstable reaction.
adds a CO2 molecule to a C5 ribulose sugar, yielding an unstable C6 molecule that cleaves into two C3 molecules.
What type of antibody or antibodies is/are found in the plasma of a person with type B blood? anti-B Both anti-A and anti-B anti-A Neither anti-A or anti-B
anti-A
What type of antibody or antibodies is/are found in the plasma of a person with type O blood? Question options: both anti-A and anti-B anti-A anti-B. neither anti-A or anti-B
both anti-A and anti-B
Which metabolic pathway is only found in plants? glycolysis oxidative phosphorylation citrate cycle carbon fixation
carbon fixation
Glycoconjugates are linked to proteins or lipids via________________. Question options: ionic bonds. London forces. covalent bonds. hydrogen bonds.
covalent bonds
Overall, the net balanced reaction of the Calvin cycle converts 3 CO2 into one acetyl-CoA. Ribulose-5-phosphate. Glucose. glyceraldehyde-3-phosphate.
glyceraldehyde-3-phosphate.
Gluconeogenesis is favored when citrate levels are __________, when AMP levels are __________, and when ATP levels are __________. high;low;high Low;high;low High; high; low Low; low; high
high;low;high
Insulin activates phosphofructokinase 2 (2PFK2). This leads to a(n) __________ in concentration of fructose 2,6 bisphosphate, which favors the __________ pathway decrease; gluconeogenesis increase; gluconeogenesis increase; glycolysis decrease; glycolysis
increase; glycolysis
Binding of glucose to hexokinase causes a conformational change in the enzyme. This is an example of the __________ model of enzyme catalysis. Glove and hand induced fit Substrate induced Lock and key
induced fit
An example of experimental biochemistry is trying an experiment and __ optimizing experimental design.
optimizing experimental design.
The photosynthetic Z scheme describes the oxidation of H2O and production of ATP and NADPH movement of electrons driven by the reflection of light energy. production of CO2. oxidation of NADPH. synthesis of glucose from CO2.
oxidation of H2O and production of ATP and NADPH movement of electrons driven by the reflection of light energy.
Hydrogen bonds form between hydrogen and _______________ or hydrogen and ______________. nitrogen, hydrogen. oxygen, nitrogen hydrogen, oxygen carbon, nitrogen
oxygen, nitrogen
How do the sources of glucose for glycolysis differ between plants and animals? Plants obtain glucose from their environment animals store glucose as starch... animal obtain glucose via carbon fixation plants obtain glucose via carbon fixation
plants obtain glucose via carbon fixation
Which is a way that light controls the Calvin cycle activity? reduced ferredoxin from the light reactions keeps thioredoxin reduced, which keeps calvin cycle enzyme in an active form
reduced ferredoxin from the light reactions keeps thioredoxin reduced, which keeps calvin cycle enzyme in an active form
The Chloroplast contains a highly folded membrane called the _______. Lumen Matrix Inner membrane thylakoid
thylakoid
Under what conditions does cyclic photophosphorylation take place? with high levels of ATP with high levels of NADH with an inactivated photosystem I with low levels of ATP
with low levels of ATP
For the glucose homopolymers amylopectin and glycogen, what is the most common carbohydrate linkage that holds the individual glucose monomers together? A. α(1→6) B. α(1→4) C. β(1→6) D. β(1→4)
α(1→4)
What glycosidic bond is found at branch points in amylopectin and glycogen? A. α(1→6) B. α(1→4) C. β(1→6) D. β(1→4)
α(1→6)
