We ****ed up
Molecules capable of enzymatic activity include... Multiple Choice RNA and DNA Proteins only DNA and proteins RNA and proteins RNA only
RNA and proteins
Which best represents an example of carbon fixation? Multiple Choice The incorporation of CO2 into organic molecules. The reduction of carbohydrates by NADPH. The oxidation of NADPH to form NADP. The regeneration of RuBP. The conversion of 1,3-BPG into G3P.
The incorporation of CO2 into organic molecules.
Sucrase uses ____ to cleave sucrose into two monosaccharides. Multiple Choice Fructose Water Carbon dioxide Glucose Oxygen
Water
In ____________ , signals pass through a cell junction from one cell to adjacent cells. Membrane-bound signals bind to receptors on adjacent cells in the process of ____________ . An example of ____________ is when cells release signals that affect themselves and nearby target cells. In ____________ , cells release signals that affect nearby target cells. Cells release signals that travel long distances to affect target cells during ____________ . induced signaling nonspecific signaling cospecific signaling autocrine signaling contact-dependent signaling direct intercellular signaling paracrine signaling endocrine signaling
direct intercellular signaling contact-dependent signaling autocrine signaling paracrine signaling endocrine signaling
The Calvin cycle takes place in the ________ of chloroplasts. Multiple Choice matrix stroma thylakoid membrane inner membrane outer membrane
stroma
Sugars can be transported into cells against their concentration gradient because of Multiple Choice osmosis. simple diffusion. facilitated diffusion. antiport with Na+. symport with Na+.
symport with Na+.
Types of membrane proteins Goes through attached to go throug attached to lipid
transmembrane proteins peripheral protins lipid anchored proteins
MEMBRANE PROTEINS Can be enzymes t/f
true
MEMBRANE PROTEINS they can be enzymes t/f
true
Arrange the electron acceptors in order from highest to lowest energy. 1 = Cytochrome c 2 = Oxygen 3 = Cytochrome c oxidase Multiple Choice 1, 2, 3 1, 3, 2 2, 3, 1 3, 1, 2 3, 2, 1
1, 3, 2
The advantage of second messengers is best described as Multiple Choice Amplification of the signal Speeds up ligand-receptor binding Enhanced specificity of the ligand Replaces the role of protein phosphatases Prevention of signal inhibition
Amplification of the signal
Place the extracellular cell feature with the appropriate cell type. Place the extracellular cell feature with the appropriate cell type. Animal, Plant Cell Cell wall collagen cellulose cross-linked glycans extracellular matrix adhesive proteins cell signaling role usually thick and rigid
Animal Cell Extracellular matrix collagen adhesive proteins cell signaling role Plant Cell cell wall cellulose cross-linked glycans usually thick and rigid
Which of the following statements is FALSE? Multiple Choice Ca2+ and cAMP are both second messengers. Ca2+ and cAMP are both involved in signal amplification. Ca2+ and cAMP will have different effects if they are synthesized in different cells. Ca2+ and cAMP are both protein kinases that will proliferate a phosphorylation cascade.
Ca2+ and cAMP are both protein kinases that will proliferate a phosphorylation cascade.
A mutation has occurred, disabling Ca2+ channels in the endoplasmic reticulum so that they can no longer open. The action of which molecule will this mutation this most affect? Multiple Choice Phospholipase C Adenylyl cyclase PKA Calmodulin Phosphodiesterase
Calmodulin
Epinephrine inhibits salivary gland activity and muscle cell contraction in the airways, yet stimulates glycogen release in muscle cells and heart muscle cell contraction. How could one hormone have opposing effects on different organs? Multiple Choice Cells in the tissues that are suppressed do not express an epinephrine receptor. Only responsive tissues are exposed to the epinephrine in the blood stream. Cells in tissues that are not responsive contain enzymes that break down epinephrine when it enters the cell. Cells in responsive tissues have signal transduction pathways. Cells in the different tissues would have epinephrine receptors coupled to different signaling pathways.
Cells in the different tissues would have epinephrine receptors coupled to different signaling pathways.
The sodium channel is formed by a channel protein. Which of the following statements about channel proteins is TRUE? Multiple Choice Channel proteins cannot be regulated by the cell. Channel proteins couple the movement of a molecule to ATP hydrolysis, which provides energy for its active transport. Channel proteins can be opened or closed by cell signaling molecules. The same molecule that opens a channel protein will also be transported by the channel protein. Channel proteins are involved in both active and passive transport.
Channel proteins can be opened or closed by cell signaling molecules.
Scientists and doctors are interested in using human stem cells cultured in the lab to produce a variety of tissues for transplants. To do this - for stem cells to become specialized blood, skin, muscle or nerve cells- they must go through which process? Multiple Choice Migration Cell growth Cell division Differentiation Apoptosis
Differentiation
Consider the biochemical pathways illustrated below. Product D will act as an allosteric inhibitor of what enzyme to regulate its own production? A--E1-->B--E2-->C--E3-->D B--E4-->E
E2
Cellular responses When a cell receives a signal, various cellular responses can occur. Classify which type of response each group of proteins could regulate. Enzyme, Structural proteins, transcription factors altering metabolism associated with breakdown of molecules activate gene expression altering cell shape causing cell movement change in sex characteristics
Enzyme altering metabolism associated with breakdown of molecules Structural Proteins altering cell shape causing cell movement Transcription Factors activate gene expression change in sex characteristics
TF Inhibiting one step in a biochemical pathway will not have any affect on the rates of the other reactions in the pathway.
F
MEMBRANE PROTEINS used to replicate dna t/f
False
Which statement regarding G-protein activation is TRUE? Multiple Choice G-proteins are activated when they are bound by an extracellular signaling molecule. G-proteins are activated by the alpha subunit separating from the beta/gamma subunit. G-proteins are activated by active G-protein-linked receptors. G-proteins are activated by Ca2+. Only the alpha subunit of the G-protein is active.
G-proteins are activated by active G-protein-linked receptors.
Which of the following statements about inositol triphosphate is FALSE? Multiple Choice It is formed in the cytoplasm. It is synthesized by a membrane-bound enzyme. It is synthesized by the enzyme phosphatase. It binds to and opens Ca2+ channels in the endoplasmic reticulum. All of these choices are correct
It is synthesized by the enzyme phosphatase.
Nicotine is a molecule that is chemically similar to acetylcholine and binds to the same receptors. What affect will nicotine have on the cell shown in the animation? Multiple Choice It will open sodium channels. It will close sodium channels. It will kill the cell. It will excite the cell. It will depress the cell.
It will open sodium channels.
Which of the following molecules might be an intracellular signaling molecule? Multiple Choice NO H2O Na+ H+
NO
TF Calcium ions serve as second messengers.
T
TF Inactivation of the alpha subunit occurs when its own phosphorylase activity removes a phosphate from the GTP.
T
TF Intracellular receptors bind to specific nucleotide sequences.
T
TF The sodium channels in the cell membrane have receptor sites for acetylcholine.
T
Why is it possible for Na+ to enter the cell when the channel is open? Multiple Choice ATP is used to provide energy to pump Na+. It is co-transported with a molecule that is moving down its gradient. Na+ are only capable of moving inside the cell. The Na+/K+ pump previously built a high concentration of Na+ on the outside of the cell, so Na+ is diffusing. Na+ first moves out of the cell across the lipid bilayer by simple diffusion, and then enters the cell by facilitated diffusion.
The Na+/K+ pump previously built a high concentration of Na+ on the outside of the cell, so Na+ is diffusing.
If a ligand were stuck in the G-protein-linked receptor, what would be the effect to the cell? Multiple Choice The pathway would be over active. The pathway would not be activated, even though the signal was present. The pathway would be deactivated by the phosphorylase activity of the G-protein's alpha subunit. The pathway would be deactivated when GDP replaced GTP in the alpha subunit. The cell would stop producing the signal molecule that got stuck.
The pathway would be over active.
When inactive, the alpha subunit of the G-protein is bound to Multiple Choice a ligand. a GTP molecule. a GDP molecule. an ADP molecule. a GTO molecule.
a GDP molecule.
The second messenger cAMP is synthesized by the enzyme Multiple Choice adenylyl cyclase. cAMP phosphodiesterase. ATPase. ligase. phosphorylase.
adenylyl cyclase.
The ligand that activates the G-protein linked receptor is ______. Multiple Choice an extracellular signaling molecule GTP Ca2+ a G-protein a second messenger
an extracellular signaling molecule
Intracellular receptors usually contain binding sites for Multiple Choice signaling molecules only. DNA only. both DNA and signaling molecules. either DNA or signaling molecules. neither DNA nor signaling molecules.
both DNA and signaling molecules.
Autotrophs use the ____________ to make organic molecules. O₂ is produced in the ____________ . The light reactions involve a series of ____________ conversions. An electron carrier called ____________ drives the Calvin cycle. H₂O provides ____________ for the light reactions. NADH light reactions organic molecules energy O2 calvin cycle NADPH ATP electrons plant pigments
calvin cycle light reactions energy NADPH electrons
Intracellular receptors may be found Multiple Choice in the cytoplasm only. in the nucleus only. either in the cytoplasm or the nucleus. either in the cytoplasm or on the cell membrane. either in the nucleus or on the cell membrane.
either in the cytoplasm or the nucleus.
How often can a sucrase molecule be used to hydrolyze sucrose? Multiple Choice once twice many times never
many times
Plant cells are attached to each other by the ___________ Animal cells attach to each other using _____________ proteins. Junctions called ____________ permit communication between plant cells. Animal cells use ___________ to attach to the extracellular matrix. Animal cells form close seals between cells using _________________ Cell connections called ____________ help adjacent animal cells communicate. middle lamella gap junctions cell junctions desmosomes collagen hemidesmosomes plasmodesmata actin adherens junction tight junctions
middle lamella. cell junction plasmodesmata hemidesmosomes tight junctions. gap junctions
Which of the following cell signaling molecules crosses the cell membrane the easiest? Multiple Choice molecules that are small and lipid-insoluble molecules that are small and lipid-soluble molecules that are small and water-soluble molecules that are large and water-soluble molecules that are large and lipid-insoluble
molecules that are small and lipid-soluble
Where is sucrase found in the human body? Multiple Choice in the liver on the microvilli of the small intestine in the pancreas on the gastric surface
on the microvilli of the small intestine
Intracellular receptors are activated by signaling molecules that ____________ the plasma membrane. In extracellular signaling, ligands bind to ____________ . Most types of enzyme-linked receptors function as ____________ . In mammals, receptors for ____________ are intracellular. enzyme horomones dna steroid horomones bind to protein kinases cell junctions cell surface receptors pass through protein horomones
pass through cell surface receptors protein kinases steroid horomones
As a result of the ligand binding to its site on the G-protein-linked receptor, Multiple Choice the G-protein changes conformation and GTP replaces the GDP on the alpha subunit. the G-protein changes conformation and the alpha subunit separates from the beta and gamma subunits. the G-protein changes conformation and GDP replaces the GTP on the alpha subunit. the G-protein changes conformation and the alpha subunit rejoins the beta and gamma subunits. the G-protein changes conformation and GTP on the alpha subunit is hydrolyzed, forming GDP.
the G-protein changes conformation and GTP replaces the GDP on the alpha subunit.
When the acetylcholine binds to the receptor sites... Multiple Choice a ligand is formed. the sodium channels open. the sodium channels remain closed. sodium ions diffuse through and enter the cell. sodium ions diffuse through and leave the cell.
the sodium channels open.
When the acetylcholine receptor sites are not occupied... Multiple Choice a ligand is formed. the sodium channels open. the sodium channels remain closed. sodium ions diffuse through and enter the cell. sodium ions diffuse through and leave the cell.
the sodium channels remain closed.
The function of the enzyme ATP synthase is to... Multiple Choice accept a proton from inside the cell membrane as it accepts electrons. utilize the energy of the proton motive force to convert ADP to ATP. produce reduced coenzymes like NADH. transfer hydrogen to the electron transport chain. shuttle electrons from NADH to a terminal electron acceptor.
utilize the energy of the proton motive force to convert ADP to ATP.
Indicate the amount of ATP produced in cellular respiration Indicate the amount of ATP produced by each enzyme or each pathway. 2 ATP No ATp 30-34 aTP Atp synthasE comPLExeS 1-1V oF the ElecTRon TranSporT Chain Glycolysis Citric acid Cycle Breakdown of pyruvate
2 = Glycolysis, Citric acid Cycle no = comPLExeS 1-1V oF the ElecTRon TranSporT Chain, Breakdown of pyruvate 30 = Atp synthasE
The initial reaction of the citric acid cycle, also called the Krebs cycle, involves the addition of a Multiple Choice 2-carbon molecule to a 4-carbon molecule. 2-carbon molecule to a 5-carbon molecule. 2-carbon molecule to a 6-carbon molecule. 3-carbon molecule to a 4-carbon molecule. 3-carbon molecule to a 5-carbon molecule.
2-carbon molecule to a 4-carbon molecule.
Sucrose concentration is higher in the cytoplasm than in the extracellular environment. Na+ concentration is higher in the extracellular environment than in the cytoplasm. Animal cells can take up sucrose against its concentration gradient using a Na+/sucrose symporter. Indicate if the following statements are true or false. A. In the Na+/sucrose symporter, Na+ is also moving against its concentration gradient. B. For the symporter to work, the cell must first establish a Na+ concentration gradient. C. A symporter works by making the phospholipid bilayer more permeable to ions and sucrose. D. Moving sucrose against its concentration gradient is a form of active transport. E. A Na+/sucrose antiporter would be capable of moving sucrose into the cell while moving Na+ out of the cell. F. Since the Na+/sucrose symporter exchanges a single sucrose for a single Na+, it can also be considered a uniporter.
A F B T C F D T E F F F
Consider the biochemical pathway below, where A, B, and C are substrates and products and E1 and E2 are the enzymes that catalyze the reactions. If Enzyme 1 (E1) is inactive, which of the following compounds will accumulate? Multiple Choice A and B A only B only B and C C only
A only
NAD+ is made from niacin, a B vitamin. Based on the animation, if someone is deficient in niacin, which of the following symptoms might they experience? Multiple Choice A reduction in energy Nausea and vomiting An inability to take up glucose into the blood An inability of the eye to distinguish light from dark
A reduction in energy
Atrazine is an herbicide that competes with Q (plastoquinone) for the electrons that are released from Photosystem II after it is struck by light. Which of the following products of the light reaction would atrazine prevent from forming? Multiple Choice ATP and oxygen ATP NADPH ATP and NADPH NADPH and oxygen
ATP and NADPH
The Calvin cycle uses ________, which are products of the light reactions of photosynthesis. Multiple Choice CO2 and H2O RuBP and O2 ADP and NADH ATP and NADPH 3-phosphoglycerate and glucose
ATP and NADPH
If the inner mitochondrial membrane was freely permeable to protons (H+) what would be the most devastating result to the cell? Multiple Choice Protons would diffuse across the membrane without going through a protein. ATP would not be produced by oxidative phosphorylation. The redox reactions in the electron transport chain would not occur. NADH would not be oxidized. ATP would not be produced by substrate level phosphorylation.
ATP would not be produced by oxidative phosphorylation.
Which best explains the role of plant pigments in photosynthesis? Multiple Choice Reduce NADP Produce photon energy Absorb light enegy Provide electrons Convert heat to electricity
Absorb light energy
Which are active, facilitated diffusion or both A Molecules move down concentration gradient B molecules move through transport protein in membrane C transport proteins are specific for structures of molecules D requires energy E molecule move against gradient
Active D, E Facilitated A Both B, C
DNP (dinitrophenol) makes the inner mitochondrial membrane permeable to H+ions. DNP blocks ATP synthesis by Multiple Choice Inhibiting ATP synthase Blocking the reduction of NADH Allowing H+ ions to cross the mitochondrial membrane without passing through ATP synthase. Preventing the formation of a H+ ion concentration gradient
Allowing H+ ions to cross the mitochondrial membrane without passing through ATP synthase.
Patients with Parkinson's Disease have been shown to have a block in the movement of autophagosomes towards lysosomes. What would you predict as a result? Multiple Choice An increased number of lysosomes in the cell Fewer extracellular autophagosomes Fewer nutrients will be needed An accumulation of old or damaged mitochondria
An accumulation of old or damaged mitochondria
What is the role of rubisco in the Calvin cycle? Multiple Choice As a catalyst to add CO2 onto RuBP. The formation of G3P. The conversion of G3P into glucose. The regeneration of RuBP. The production of O2 from CO2.
As a catalyst to add CO2 onto RuBP.
Rank these reactions from least to most energetically favorable. Ranking A Open choices for matching ATP to ADP and Pi, -7.3kcal/mol B Open choices for matching Glucose to Glucose-6-P, +3.3kcal/mol C Open choices for matching PEP to pyruvate, -14.8kcal/mol D Open choices for matching Glucose-6-P to Fructose-6-P, +0.4kcal/mol
B D A C
Osmosis and cell structure Outside is isotonic Outside is hypertonic Outside is hypotonic
Balanced water moves out, cell is flat (plasmolysis, crenation) water move in, cell swell (lysis)
In the example above, how does the final product of the pathway inhibit the pathway? Multiple Choice By binding to the active site of the last enzyme in the pathway. By binding to the substrate of the first reaction. By binding to an allosteric site of the first enzyme in the pathway. By binding to the active site of the first enzyme in the pathway. By binding to the product of the first reaction.
By binding to an allosteric site of the first enzyme in the pathway.
How do electrons enter the electron transport chain? Multiple Choice By the oxidation of NADH By the reduction of NADH By the reduction of oxygen By the oxidation of water By the reduction of water
By the oxidation of NADH
NAD+ is a coenzyme for many enzymes involved in redox reactions. This means that Multiple Choice NAD+ has an active site. All enzymes involved in redox reactions bind NAD+. Enzymes that use NAD+ as a coenzyme will not function properly if NAD+ is not available. NAD+ is an inhibitor of many enzymes involved in redox chemistry.
Enzymes that use NAD+ as a coenzyme will not function properly if NAD+ is not available.
The hormone insulin is a protein produced in the pancreas and then secreted into the blood stream after a meal to increase glucose uptake by tissues. Which of the following mechanisms would be used to secrete insulin from the pancreas? Active transport Facilitated diffusion Diffusion Endocytosis Exocytosis
Exocytosis
TF If the end product of the biochemical pathway in the animation increases, it would eventually result in an increase in substrate 2.
F
TF Photosynthetic pigments are found in the plasma membrane of a plant cell.
F
TF: Unlike simple diffusion, facilitated diffusion requires energy expenditure by the cell.
F
Determine if each statement about the molecule in the reaction below is true or false. Img 7 Phosphoenolpyruvate is a product Mg+2 ion is a cofactor Pyruvate kinase is an enzyme Pyruvate is a substrate
F T T F
Aquaoporin allows water to move rapidly across a plasma membrane. Which is best FD usin transporter AT usin transporter FD usin channel AT using a channel
FD usin channel
TF The formation of ATP as a result of the activity of the electron transport system is termed substrate-level phosphorylation.
False
Which of the following molecules are most likely to pass through the membrane by facilitated diffusion? Multiple Choice H2O and sucrose H2O and O2. CO2 and O2. CO2 and H2O.
H2O and sucrose
Digoxin is an inhibitor of Na+/K+ ATPase that is used to treat irregular heartbeats (medical term: atrial fibrillation). Digoxin slows the heartbeat by raising intracellular calcium levels. What is the most reasonable explanation for how digoxin can raise intracellular calcium concentrations through inhibiting Na+/K+ ATPase? Multiple Choice Na+/K+ ATPase acts to shuttle Ca2+ out of the cell. Digoxin inhibits Na+/K+ ATPase, preventing it from shuttling Ca2+ out of the cell. As a result, intracellular Ca2+ levels increase. Inhibiting Na+/K+ ATPase results in a higher than normal intracellular Na+ concentration. This reduces the effectiveness of the Na+/Ca2+ antiporter. As a result, intracellular Ca2+ levels increase. Inhibiting Na+/K+ ATPase results in a lower than normal intracellular Na+ concentration. This reduces the effectiveness of the Na+/Ca2+ antiporter. As a result, intracellular Ca2+ levels increase. Inhibiting Na+/K+ ATPase results in a lower than normal extracellular K+ concentration. This increases the effectiveness of a K+/Ca2+ symporter that drives the influx of both K+ and Ca2+. As a result, intracellular Ca2+ levels increase.
Inhibiting Na+/K+ ATPase results in a higher than normal intracellular Na+ concentration. This reduces the effectiveness of the Na+/Ca2+ antiporter. As a result, intracellular Ca2+ levels increase.
Consider the biochemical pathways illustrated below. If product D is abundant, why is it preferable to inhibit E2 rather than E1? A--E1-->B--E2-->C--E3-->D B--E4-->E Inhibition of E2 will prevent the production of D, but still allow synthesis of E. Inhibition of E2 will prevent the production of D, but still allow synthesis of B. E1 can only be regulated by B or E. It is not possible for D to regulate E1 because it is too far upstream in the biochemical pathway.
Inhibition of E2 will prevent the production of D, but still allow synthesis of E.
What happens when the coenzyme NAD+ gains an H atom? Multiple Choice It also gains a proton causing it to be reduced. It also gains an electron causing it to be oxidized. It also gains a proton causing it to be oxidized. It loses energy. It also gains an electron causing it to be reduced.
It also gains an electron causing it to be reduced.
Based on the reaction in the animation, what can you say about the change in free energy of the cleavage of sucrose into glucose and fructose? Multiple Choice It is negative and the reaction is endergonic. It is positive and the reaction is endergonic. It is negative and the reaction is exergonic. It is positive and the reaction is exergonic.
It is negative and the reaction is exergonic.
Light reaction vs. Calvin Cycle Place the items in the appropriate photosynthesis pathway. oxidation of water atp is a product reduction of carbon compounds reduction by nadph atp is consumed nadph is a product
Light oxidation of water atp is a product nadph is a product Calvin reduction of carbon compounds reduction by nadph atp is consumed
Electrons are brought to the electron transport system by the oxidation of Multiple Choice NADH. FADH2. ATP. oxygen. NADH and FADH2.
NADH and FADH2.
The oxidation of NADH results in the formation of more ATP molecules compared to the oxidation of FADH2 because Multiple Choice NADH enters the electron transport chain at an earlier point than FADH2. NADH contributes electrons directly to ATP synthase. the oxidation of FADH2 requires an input of 1 ATP molecule. FADH2 isn't produced until a later stage in the citric acid cycle.
NADH enters the electron transport chain at an earlier point than FADH2.
Paraquat is an herbicide that competes with FD (Ferredoxin) for the electrons that are released from Photosystem I after it is struck by light. Which of the following products of the light reaction would paraquat prevent from forming? Multiple Choice NADPH NADPH and ATP ATP ATP and oxygen NADPH and oxygen
NADPH
Based on the figure above, what is the final electron acceptor? Multiple Choice NO2- ATP NADH NO3- H2O
NO3-
Photosynthesis vs. respiration Place the statements in the appropriate pathway. Photosynthesis cellular respiration Takes in CO2 Convert H2O to O2 Found only in photoautotrophs produces organic molecules consumes glucose produces CO2 O2 exits as H2O
Photo Takes in CO2 Found only in photoautotrophs produces organic molecules Convert H2O to O2 Cellular consumes glucose O2 exits as H2O produces CO2
If a chemical that inhibits Enzyme #3 was added to the system containing the biochemical pathway illustrated in the animation, which of the following would result? Check All That Apply Product #1 would accumulate in the system. Product #2 would accumulate in the system. Substrate #1 would accumulate in the system. Substrate #1 would become depleted. Substrate #3 would accumulate in the system. Product #4 would accumulate in the system. Substrate #4 would be depleted in the system. The final product would be depleted in the system.
Product #2 would accumulate in the system. Substrate #3 would accumulate in the system. Substrate #4 would be depleted in the system. The final product would be depleted in the system.
Lipoproteins like LDL and HDL transport lipids and proteins through the blood stream. Receptors on cells can bind to the lipoproteins and remove them from the blood, using the lipids for energy and to produce membranes. Which of the following mechanisms would be used to move a lipoprotein into a cell? Multiple Choice Active transport Facilitated diffusion Receptor-mediated endocytosis Endocytosis Exocytosis
Receptor-mediated endocytosis
Which are simple and facilitated diffusion Gases salts sugars water proteins ethanol
SD gases water ethanol FD salt sugar proteins
Why must the electron transport chain proteins and molecules be embedded in a membrane? Multiple Choice So that ATP can be formed in the mitochondrial matrix So that protons can be compartmentalized and form a gradient So that the product of one reaction can become the reactant of the next reaction Because the cristae provide copious amounts of surface area So that prosthetic groups can more efficiently bind to electrons
So that protons can be compartmentalized and form a gradient
What happens to sucrase when it binds to sucrose? Multiple Choice Sucrase releases energy to the sucrose. Sucrase becomes denatured. Sucrase is cleaved in half. Sucrase goes through a conformational change.
Sucrase goes through a conformational change.
A mutation occurred in the gene that encodes the enzyme sucrase, resulting in a single amino acid substitution in the active site of the enzyme; a polar amino acid changed to a nonpolar amino acid. What is probably the result of this mutation. Multiple Choice A single amino acid substitution will probably not affect the enzyme. Sucrase will not be able to bind sucrose in the active site. Sucrase will bind sucrose, but will not catalyze the hydrolysis reaction. Sucrase will no longer be specific to sucrose. It will now hydrolyze a variety of disaccharides.
Sucrase will not be able to bind sucrose in the active site.
GLUT1 deficiency syndrome is a rare genetic disorder where mutations in the gene encoding GLUT1 reduce or eliminate the function of the GLUT1 protein. Affected individuals suffer from seizures along with a number of potential neurological problems. What would be the most effective therapy to treat patients suffering from this disorder? Multiple Choice Switch to a high glucose diet to overcome the deficient transport Switch to a diet containing carbohydrates other than glucose to circumvent the deficient transport Regularly inject GLUT1 into the patient's blood to serve as a replacement for the deficient transporter Treat with drugs that will elevate ATP levels in the blood-brain barrier and promote the active transport of glucose by GLUT1
Switch to a diet containing carbohydrates other than glucose to circumvent the deficient transport
TF In a biochemical pathway, the product released by the first enzyme becomes the substrate for the second enzyme.
T
TF Plastoquinone is the primary electron acceptor for electrons leaving photosystem II.
T
TF Whenever a molecule is oxidized, another molecule must be reduced.
T
ATP is used in the cell to transfer energy. ATP is used in the cell to transfer energy. Indicate if the following statements about ATP are true or false. When ATP is used in a reaction, the last phosphate is transferred to the substrate. The release of the last phosphate from ATP is endergonic. Once phosphates are released from ATP they can be added back in an endergonic reaction. Creatine-P to creatine has a ΔG of -11kcal/mole and thus can be used to generate ATP from ADP. When ATP is hydrolyzed to form ADP, the energy is released into the cytoplasm where enzymes use it to run endergonic reactions.
T F T T F
Alzheimer's disease is characterized by an accumulation of proteins such as beta-amyloid protein in the cells. Beta-amyloid mRNA levels do not increase in patients with Alzheimer's disease. Explain how beta-amyloid protein levels increase in these patients' cells. Multiple Choice The beta-amyloid proteins have an increased rate of synthesis. The beta-amyloid proteins are not broken down and recycled. The beta-amyloid proteins are secreted from the cell. The beta-amyloid proteins have a decreased rate of synthesis.
The beta-amyloid proteins are not broken down and recycled.
The plasma membrane Ca2+-ATPase is a pump that functions in the primary active transport of Ca2+ out of the cell. What features do you expect of this pump and the cellular environment? Choose all that apply. Check All That Apply It transports Na+ and K+ ions It is an antiporter The extracellular Ca2+ concentration is higher than the intracellular Ca2+ concentration It hydrolyzes ATP It is capable of undergoing a conformational change The affinity for Ca2+ is low when the pump is bound to phosphate. It transports Ca2+ down its concentration gradient
The extracellular Ca2+ concentration is higher than the intracellular Ca2+ concentration It hydrolyzes ATP It is capable of undergoing a conformational change The affinity for Ca2+ is low when the pump is bound to phosphate.
Based on the animation, which of the following observations is true? Multiple Choice img 10 An enzyme could create different products depending on which substrate it started with. The product from one reaction served as the substrate for the next reaction. Each enzyme only performed its reaction once. Each enzyme was catalyzing the same reaction. Multiple final products were formed depending on which enzyme catalyzed the last reaction.
The product from one reaction served as the substrate for the next reaction.
The energy for producing organic molecules in plants is directly driven by: Multiple Choice The use of water to transfer the energy of hydrolysis to enzymes. The use of NADPH to carry photons to the Calvin cycle. The use of light to provide electrons for oxidation and reduction reactions. The use of rubisco to collect energy from ATP made during the light reactions. The use of chlorophyll to transfer electrons from photons to other pigments.
The use of light to provide electrons for oxidation and reduction reactions.
What function do many B vitamins serve in the production of energy? Multiple Choice They function as energy sources. They function as enzymes. They function as co-enzymes. They function as hypoenzymes.
They function as co-enzymes.
Why is pyruvate converted to lactate in anaerobic conditions? Multiple Choice To regenerate NAD+ from NADH and keep glycolysis functioning. To regenerate NADH from NAD+ and keep glycolysis functioning. To produce more oxygen to allow the electron transport chain to resume. The conversion of pyruvate to lactate also produces ATP which keeps the cell alive. The conversion of pyruvate to lactate requires ATP and is thus exergonic.
To regenerate NAD+ from NADH and keep glycolysis functioning.
MEMBRANE PROTIENS Can aid in the transport of molecules across the membrane T/F
True
Leaves exposed to light of wavelength 680 nm alone or 700nm alone will undergo a similar amount of photosynthesis. However, when both wavelengths are shined at the same time more than double the amount of photosynthesis occurred. Which of the following best explains this observation? Multiple Choice When both wavelengths are used twice as many photons exciting photosystem II and producing twice as much ATP When both wavelengths are used, electrons can pass from photosystem II to photosystem I generating more ATP. Photosystem I cannot be activated unless photosystem II is first activate. The amount of ATP produced will be the sum of ATP produced by exciting photosystems I and II.
When both wavelengths are used, electrons can pass from photosystem II to photosystem I generating more ATP.
Consider the biochemical pathway used to synthesize the amino acid proline. A large increase in the level of proline will most likely lead to Multiple Choice a decrease in proline production. proline being converted to praline. no change in the rate of proline production. a further increase in proline production. increased breakdown of proline.
a decrease in proline production.
A hydrogen atom consists of Multiple Choice protons only. a variable number of protons and electrons. a proton and an electron. electrons only. a proton and several electrons.
a proton and an electron.
Fatty acids and some amino acids are converted directly into _____________ for ATP production. Multiple Choice NADH acetyl CoA glucose FADH2 pyruvate
acetyl CoA
Before entering the citric acid cycle, also called the Krebs cycle, pyruvate is converted to Multiple Choice glucose. H2O and CO2. acetic acid. acetyl-CoA. oxaloacetate.
acetyl-CoA.
The term ____________ describes cellular respiration in the absence of ____________ . Oxygen is the final electron acceptor in ____________ respiration. The breakdown of organic molecules without oxygen is called ____________ . During fermentation, yeast break down pyruvate into ____________ and acetaldehyde. Aerobic respiration produces ____________ molecules whereas anaerobic respiration produces ____________ molecules. Aerobic 34-38 ATP anaerobic CO2 NADH fermentation glucose oxygen 2 ATP ADP FADH2
anaerobic, oxygen Aerobic fermentation CO2 34-38 ATP, 2 ATP
Facilitated diffusion requires Multiple Choice enzymes. carrier proteins. lipid carriers. carbohydrate carriers. lipid or carbohydrate carriers.
carrier proteins
RNA exposed to a/an ____________ will release ____________ which the cell can recycle. Protein exposed to a/an ____________ will release ____________ which the cell can recycle. autophagy proteasome amio acids fatty acids exonuclease nucleotides
exonuclease nucleotides proteasome amio acids
MEMBRANE PROTEINS they are totally water soluble t/f
false
In cellular respiration, carbon dioxide is formed from the oxidation of the following: Multiple Choice water NADH cytochrome oxidase oxygen glucose
glucose
Which of the following is the correct equation for aerobic cellular respiration? Multiple Choice glucose + 6 O2 + 6 H2O→ 6 CO2 + energy intermediates + heat glucose + 6 O2 → 6 CO2 + 6 H2O + energy intermediates + heat glucose + 6 O2 + 6 CO2 → 6 H2O + energy intermediates + heat glucose + 6 O2 + heat → 6 CO2 + 6 H2O + energy intermediates glucose + 6 CO2 → 6 O2 + 6 H2O + energy intermediates + heat
glucose + 6 O2 → 6 CO2 + 6 H2O + energy intermediates + heat
Place the cellular respiration pathways in their correct locations. Oxidative Phosphorylation Breakdown of pyruvate Citric acid cycle glycolyisis
glycolysis Breakdown of pyruvate citric acit cycle oxidtive phosphorlation
The movement of protons through ATP synthase occurs from the Multiple Choice matrix to the intermembrane space. matrix to the cytoplasm. intermembrane space to the matrix. intermembrane space to the cytoplasm. cytoplasm to the intermembrane space.
intermembrane space to the matrix.
What is the source of energy used to power the sodium-potassium pump? Multiple Choice hydrolysis of ATP formation of ATP binding of ATP release of phosphate diffusion of Na+ down its gradient
hydrolysis of ATP
GLUT1 is a glucose transporter that is responsible for the facilitated diffusion of glucose across the blood-brain barrier. GLUT1 deficiency syndrome is a rare genetic disorder where mutations in the gene encoding GLUT1 reduce or eliminate the function of the GLUT1 protein. Affected individuals suffer from seizures along with a number of potential neurological problems. What is the link between GLUT1 dysfunction and these neurological complications? Multiple Choice sporadic and uncontrolled diffusion of glucose from the blood to the brain diffusion of glucose from the brain to the blood excessive and constant diffusion of glucose from the blood to the brain insufficient diffusion of glucose from the blood to the brain
insufficient diffusion of glucose from the blood to the brain
Photosynthesis uses ____________ to produce ATP, NADPH, and O₂. ____________ captures the light energy for photosynthesis. ATP and NADPH drive the ____________ . The Calvin cycle performs ____________ during photosynthesis. Water is converted to oxygen and releases electrons in the ____________ . carbon fixation chlorophyll rubisco light energy light reaction photorespiration sheath cells RuBP calvin cycle
light energy chlorophyll calvin cycle carbon fixation light reaction
Enzymes catalyze reactions by Multiple Choice lowering activation energy. decreasing the entropy of the reaction. adding energy to the reaction. raising activation energy.
lowering activation energy.
Consider the biochemical pathway below, where A, B, and C are substrates and products and E1 and E2 are the enzymes that catalyze the reactions. Enzyme 1 (E1) can utilize Multiple Choice only A as substrate. neither A nor B as substrate. both A and B as substrates. either A or B as substrate, but not both. only B as substrate.
only A as substrate.
Cells obtain energy by ________ food molecules such as glucose. Multiple Choice redoxing reducing oxidizing phosphorylating anabolizing
oxidizing
During aerobic respiration, the last carrier protein transfers a pair of electrons to... Multiple Choice water. NADH. oxygen. Coenzyme Q. a proton (H+).
oxygen
Creation of a proton gradient by the electron transport chain represents Multiple Choice heat potential energy kinetic energy a high pH mechanical energy
potential energy
If glycolysis was blocked in yeast, which of the following would decrease in concentration? Multiple Choice oxygen ethanol NAD+ pyruvate
pyruvate
The sodium-potassium pump functions to pump Multiple Choice sodium ions out of the cell and potassium ions into the cell. sodium ions into the cell and potassium ions out of the cell. sodium and potassium ions into the cell. sodium and potassium ions out of the cell. sodium and potassium ions in both directions across the cell membrane.
sodium ions out of the cell and potassium ions into the cell.
In feedback inhibition, the inhibitor of the biochemical pathway is often Multiple Choice the substrate of the enzyme inhibited. a substance that is produced towards the middle of the biochemical pathway. the product of the enzyme inhibited. a product of another biochemical pathway. the final product of the biochemical pathway.
the final product of the biochemical pathway.
Which of the following is the most direct source of energy for cotransport? Multiple Choice the movement of one of the transported substances up its concentration gradient the movement of one of the transported substances down its concentration gradient ATP hydrolysis ATP formation cotransport requires no energy
the movement of one of the transported substances down its concentration gradient
