Exam 2 Review

On Halloween night three students snuck (or broke) into an old boarded up house that was rumored to be haunted. As they were walking through the house, suddenly a pack of rats ran out of a hallway. Two of the students screamed and fainted on the floor. On the other hand, their friend stood alone as if nothing had happened. Apparently, he is a "mutant" such that adrenaline signaling does not function. List all molecules that might be malfunctioning in the student with non-functional adrenaline signaling.

any part of the adrenylyn signalling pathway -producing ligand -receptor -adenylyl cyclase -PKA -substrates -target protein

Which of the following is/are substrates of (molecules input into) the Citric acid cycle? a. pyruvate b. acetyl-CoA c. NAD+ d.CO2 e. glucose

b and c

Which of the following is/are a product(s) of glycolysis? a. Glucose b. Pyruvate c. NADH d. ATP e. Acetyl-CoA

b,c and d

DNP (2,4-dinitrophenol) is an effective weight-loss agent that was used in diet pills in the 1930s. It has since been removed from the market (though it is available online) because of serious side effects such as fever, cataracts, rashes, and sometimes death. DNP inserts into the inner mitochondrial membrane and shuttles protons between the intermembrane space and the matrix. Based on this information, which of the following might you predict? a. increased hydrolysis of ATP b. reduced ATP production c. dissipation of the proton gradient d. increased ATP production e. decreased difference in pH between the matrix and intermembrane space

b,c, and e

The total amount of ATP produced per pyruvate molecule is a. 32 b. 12.5 c. 10 d. 28

b. 12.5

What molecule from the Calvin Cycle would get "backed up" if the Photosynthetic Electron Transport Chain became nonfunctional? a. triose phosphate b. 3-PGA c. 2-PGA d. RuBP e. NADPH

b. 3-PGA

The hydrolysis of _____ is an exergonic reaction that drives many endergonic reactions in a cell. a. cAMP b. ATP c. AMP d. oxygen

b. ATP

The Calvin Cycle receives energy from what process inside the cell? a. Citric Acid Cycle b. Glycolysis c. Fermentation d. Photosynthetic ETC

d. Photosynthetic ETC

The degree of disorder is called ________________.

entropy

Bonds linking phosphate groups have ____________ potential energy.

high

What is a hydrophilic ligand? What is a hydrophobic ligand?

hydrophillic-(growth factor) cant pass through plasma membrane; receptor is on cell surface hydrophobic-(steroid) can pass through plasma membrane; receptor in cytoplasm/nucleus

What type of cell signaling requires the least amount of distance between cells?

juxtacrine

Energy of motion is ________ energy.

kinetic

A signaling molecules is called a ___________________. This molecule specifically binds to a receptor.

ligand

Describe two strategies that plants use to limit the formation and effects of ROS.

xanthrophills antioxidants cyclic electron transport

What are oncogenes and tumor suppressors? What happens if one of these or both are mutated?

-cancer causing genes -stop cancerous pathways -1=ususally nothing -both=cancer

What is Rubisco? Does it work fast or slow? Why does Rubisco work at this pace?

-gets CO2 to bind with RuBP -slow -to get CO2 not O2

Enzymes are remarkable biological molecules that catalyze chemical reactions without burning ourselves. The site for chemical reactions in an enzyme is called (A) site and consists of several amino acids. In many cases, these amino acids are not next to each other in its (B) structure, but assemble in one functional unit in its (C) structure. Therefore, folding enzymes into the right configuration is essential. A: B: C:

A:active site B:primary structure C:tertiary

Chemical reactions always have an unstable state called the (A) state even in exergonic (or spontaneous) reactions. This state has a high free energy called (B), so we have to provide additional energy to push the reaction forward to get products from reactants. In the cell, (C) help reduce (B) so that chemical reactions go faster (and without burning ourselves). Since (C) themselves do not change, (C) are also called (D). A: B: C: D:

A:transition state B:activation energy C:enzymes D:catylists

T/F In a plant cell, all stages of cellular respiration are carried out in the cytoplasm.

F

T/F Keratinocytes are pigment cells contained in the epidermis of skin.

F

T/F Oxidation is the gain of electrons

F

This is a hypothetical story. The grocery store in Athens has green leafy plants for salad. One is from Florida, and the other is from Alaska. Both look delicious, but Dr. Van Brocklyn tells you that the one from Florida might be better for you. Why is that?

Florida has more sunlight which yeilds more antixidants which yeilds less ROS

The amount of energy available to do work is called _________ _________ __________.

Gibbs Free Energy

T/F A red blood cell signaling to a white blood cell inside of the same blood vessel is an example of paracrine signaling.

T

T/F Although cellular respiration is typically thought of as an aerobic process, glycolysis itself is actually anaerobic.

T

T/F Competitive inhibitors bind to the active site of the enzyme and prevent the substrate from binding.

T

T/F Glucose is more efficient than fat.

T

T/F The ATP produced during glycolysis is the result of substrate-level phosphorylation.

T

Suppose you discovered a mutant strain of spinach in which the thylakoid membranes were slightly permeable to protons, thus allowing a slow leakage. (Remember that normal membranes are not permeable to protons at all.) How might this defect affect the yield of ATP and/or NADPH from the light reactions? a. NADPH yield would decrease. b. NADPH yield would increase. c. ATP yield would decrease. d. ATP yield would increase. e. There would be no change.

a and c

You are studying a reaction in which the produces have less Gibbs free energy than the reactants. Which of the following is true about this reaction? a. the reaction is considered spontaneous b. the reaction will go to completion very quickly c. the reaction will have a low activation energy d. the reaction is exergonic

a and d

The photosynthetic electron transport chain requires two photosystems in order to perform two separate essential tasks. What are they? a. strip electrons from water molecules b. energize multiple antenna chlorophyll molecules, and reduce FADH to FADH2. c. reduce O2 to water, and carboxylate RuBP. d. pass electrons to plastoquinone, and pump protons into the thylakoid lumen. e. reduce NADP+ to NADPH

a and e

The enzyme PFK-1 is inhibited by a. Citrate b. AMP c. ADP d. NAD+

a. Citrate

_________ phosphorylation provides more ATP than ________________ phosphorylation. a. Oxidative; substrate-level b. Substrate-level; oxidative c. Citric acid; oxidative d. Metabolic; substrate-level

a. Oxidative; substrate-level

Normally, xanthophylls are present in the thylakoid membrane and are associated with photosystem II. If a mutation occurred that reduced the amount of xanthophylls in the thylakoid membrane, which of the following would you predict would happen? a. The levels of harmful, reactive oxygen species in the cell would increase. b. NADPH production would increase under conditions of intense light. c. Levels of reactive oxygen species in the thylakoid lumen would drop dramatically. d. The rate of cyclic electron transport would increase.

a. The levels of harmful, reactive oxygen species in the cell would increase.

The degree of disorder is called _______. a. entropy b. energy c. work d. potential difference

a. entropy

Which of the following stages of respiration does not take place within the mitochondria? a. glycolysis b. citric acid cycle c. electron transport chain e. all of the above stages occur within the mitochondria

a. glycolysis

What is the best characterization of the minus end of a dynamic filament? a. it is slow growing b. it is fast growing

a. it is slow growing

In the dark, starfish are darkly colored. This is because melanin granules are dispersed outward by__________. In the light, starfish are more lightly colored. This is because melanin granules are aggregated toward the center by_____________. a. kinesin, dynein b. dynein, kinesin c. myosin, dynein d. kinesin, myosin

a. kinesin, dynein

Oxidation is the ______ of electrons, while reduction is the _____ of electrons. ______ ______ are molecules that can give away electrons, while _____ _____ are molecules that can receive electrons. a. loss, gain; reducing agents, oxidizing agents b. loss, gain; oxidizing agents, reducing agents c. gain, loss; reducing agents, oxidizing agents d. gain, loss; oxidizing agents, reducing agents

a. loss, gain; reducing agents, oxidizing agents

Myosin is a motor protein found attached to: a. microfilaments b. intermediate filaments c. microtubules

a. microfilaments

Which is the correct order for these steps in cell signaling? a. receptor activation, signal transduction, then response b. receptor activation, response, then signal transduction c. response, signal transduction, then termination

a. receptor activation, signal transduction, then response

Very low concentrations of detergent make membranes leaky to small molecules and ions without damaging proteins. In isolated mitochondria exposed to detergent, the molecules of the electron transport chain and of ATP synthase remain intact. Do you expect ATP synthesis to continue in the presence of low concentrations of detergent? a. Yes, because all enzymes and electron carriers are functional. b. No, because with a leaky membrane, the proton gradient cannot be maintained. c. No, because leaky membranes do not allow NADH and FADH2 to donate their electrons to the electron transport chain. d. No, because leaky membranes inhibit glycolysis.

b. No, because with a leaky membrane, the proton gradient cannot be maintained.

The Photosynthetic ETC occurs in the _______________. a. Lumen b. Thylakoid Membrane c. Matrix c. Stroma

b. Thylakoid Membrane

Enzymes decrease the a. amount of substrates b. activation energy c. amount of products d. entropy

b. activation energy

Cellular respiration is a series of ________ reactions. a. phosphorylation b. catabolic c. anabolic

b. catabolic

The dermis is an example of what type of tissue? a. epithelial b. connective c. muscle d. nerve

b. connective

Which of the following is not a cellular function of microfilaments? a. transport of organelles b. flagellar movement c. organization of proteins in the plasma membrane d. formation of daughter cells following mitosis

b. flagellar movement

A scientist is studying pigmentation in the skin of salamanders. She has bred a mutant salamander that is very lightly pigmented. Microscopic examination of skin cells from this animal shows that pigment granules, which would normally be dispersed throughout the cytoplasm, are concentrated near the nucleus, causing the light color. She hypothesizes that there is a problem with what motor protein in these cells? a. myosin b. kinesin c. dynein

b. kinesin

Oligomycin is an antibiotic that binds ATP synthase, blocking the flow of protons through the enzyme's proton channel. In addition to preventing synthesis of ATP, what additional effect might you expect in response to the presence of oligomycin? a. higher pH in the intermembrane space b. lower pH in the intermembrane space c. a buildup of protons in the mitochondrial matrix

b. lower pH in the intermembrane space

A scientist is studying pigmentation in the skin of salamanders. She has bred a mutant salamander that is very lightly pigmented. Microscopic examination of skin cells from this animal shows that pigment granules, which would normally be dispersed throughout the cytoplasm, are concentrated near the nucleus, causing the light color. Further studies show that all the motor proteins are normal. She then changes her hypothesis to state that something may be wrong with which cytoskeletal fiber? a. microfilaments b. microtubules c. intermediate filaments

b. microtubules

Which of the following is not a cellular function associated with the microtubule cytoskeleton? a. movement of cilia or flagella b. muscle contraction c. mitosis d. organization of organelles

b. muscle contraction

A catabolic reaction involves a. using energy to build subunits from macromolecules b. receiving energy from breaking down macromolecules c. using energy to breakdown macromolecules into subunits d. receiving energy from breaking down subunits

b. receiving energy from breaking down macromolecules

A scientist is studying the structure and function of epithelial cell layers. He treats the epithelium with a signaling molecule and notes that it becomes leaky. That is to say, substances can pass from the apical side of the epithelium to the basolateral side following treatment. He hypothesizes that the signaling molecule has caused disruption of what type of cell junction? a. adherens junctions b. tight junctions c. desmosomes d. hemidesmosomes e. gap junctions

b. tight junctions

What function do antenna chlorophyll molecules perform? a. strip electrons from water molecules to start the ETC b. transfer light energy to other antenna chlorophyll molecules c. pass electrons to reaction center chlorophyll d. all of the above

b. transfer light energy to other antenna chlorophyll molecules

Anabolism is the ________________ ________________ of molecules.

building up

Motor proteins that transport cargos such as pigment granules on microtubules are kinesin and dynein. Kinesin transports its cargos to the plus end, and dynein transports its cargos to the minus end. As zebrafish keeper, you feed them every day. In one morning, you accidentally dropped a tablet of unknown chemical in one of aquariums with 100 zebrafish babies. Alas, you saw all the babies were black (or dark colored) next morning. Based on this observation, you can conclude that this chemical is likely to inhibit: a. Kinesin function-walking motion b. ATPase activity in kinesin c. ATPase activity in dynein d. Microtubule polymerization e. Dynein function-walking motion f. Microfilament polymerization

c and e

You examine a cell that has a high level of activity of the enzyme PFK-1. This cell is likely to have: a. A high level of ATP b. A high level of citrate c. A high level of ADP d. B and C e. All of the above

c. A high level of ADP

What is the correct order of events in G protein-coupled receptor signaling after activation by adrenaline? a. G protein activation, protein kinase A activation, cAMP production, adenylyl cyclase activation b. protein kinase A activation, G protein activation, adenylyl cyclase activation, cAMP production c. G protein activation, adenylyl cyclase activation, cAMP production, protein kinase A activation d. adenylyl cyclase activation, G protein activation, cAMP production, protein kinase A activation

c. G protein activation, adenylyl cyclase activation, cAMP production, protein kinase A activation

You are studying an enzyme inhibitor. You notice that if you increase the concentration of substrate the inhibitor has less effect. Which of the following is likely true of this inhibitor? a. It is a non-competitive inhibitor b. It is an irreversible inhibitor c. It is a competitive inhibitor d. It is an allosteric inhibitor

c. It is a competitive inhibitor

Phosphatases are a family of enzymes that remove phosphate groups from specific proteins; these phosphate groups had been added to the proteins by protein kinases. Vanadate is an inhibitor of phosphatases in eukaryotic cells. What effect would vanadate have on the response of cells to signals received by receptor kinases? a. The signal would still bind to the receptor, so there would be no effect. b. The response of the cell would be shorter than it normally would. c. The response of the cell would last longer than it normally would.

c. The response of the cell would last longer than it normally would.

In the metabolic pathway illustrated below, the starting material (substrate A) is converted equally to one of two end products, E or G. Use the diagram of the pathway below to answer the following questions. Letters indicate the substrates and products, and numbers indicate the enzymes. In this pathway, the intermediate, C, is a substrate for both enzyme 3 and enzyme 5 and is converted with equal efficiency to D and F. If end product E inhibits enzyme 1, which of the following would you expect to observe? a. an increase in the production of G b. a decrease in the production of E, but no change in the production of G c. a decrease in the production of E and G d. an increase in the production of A

c. a decrease in the production of E and G

A mutation in the gene for myosin could lead to what problem? a. a defect in cilia and flagella b. a loss of vesicle transport along microtubules c. a defect in crawling-like cell movement

c. a defect in crawling-like cell movement

In the metabolic pathway illustrated below, the starting material (substrate A) is converted equally to one of two end products, E or G. Use the diagram of the pathway below to answer the following questions. Letters indicate the substrates and products, and numbers indicate the enzymes. In this pathway, the intermediate, C, is a substrate for both enzyme 3 and enzyme 5 and is converted with equal efficiency to D and F. If end product G inhibits enzyme 5, which of the following would you expect to observe as the amount of G increases in the cell? a. an increase in the production of C. b. an increase in the production of B c. an increase in the production of E d. a decrease in the production of D e. an increase in the production of G

c. an increase in the production of E

At the end of glycolysis, the carbon molecules originally found in the starting glucose molecule are in the form of: a. two ATP molecules b. two NADP molecules c. two pyruvate molecules

c. two pyruvate molecules

What is oxidized and what is reduced in cellular respiration? What is oxidized and what is reduced in photosynthesis?

cell respiration oxidized=glucose reduced=oxygen photosynthesis oxidized=water reduced=carbon dioxide

In patients who suffer epidermolysis bullosa, epidermal cells in skin are easily peeled off causing severe blistering. Epidermolysis bullosa is due to defective keratin genes. They produce keratins that cannot polymerize properly to make strong intermediate filaments. Which statement properly interprets this observation? a. Abnormal formation of keratin intermediate filaments makes epidermis very rigid and brittle. b. Abnormal formation of keratin intermediate filaments makes skin cells to become round and float. c. Proper formation of keratin intermediate filaments is required for skin cells to be flat in shape. d. Proper formation of keratin intermediate filaments is required for stronger cell adhesion between epidermal cells.

d. Proper formation of keratin intermediate filaments is required for stronger cell adhesion between epidermal cells.

You are creating a drug that aims to stop cancer cells from metastasizing. In order to do this, you must halt the motility of the cancerous cells. As we know cancer cells metastasize with the use of a crawling motion and integrins. What cytoskeletal structure would you want to degrade in order to disrupt to movement of the cancerous cells? a. microtubules b. desmosomes c. hemidesmesomes d. actin microfilaments e. intermediate filaments

d. actin microfilaments

Kinesin is a motor protein found attached to: a. intermediate filaments b. tubulin c. microfilaments d. microtubules

d. microtubules

Electrons farthest from the nucleus have the ____________. a. same amount of energy as electrons closest to the nucleus b. least potential energy c. most kinetic energy d. most potential energy

d. most potential energy

In nerve cells, the centrosome is located near the nucleus. Vesicles move from near the nucleus to the end of the axon along microtubules. Based on these two facts, it is possible to conclude that these vesicles are moving in the ____________ direction on the microtubule using the motor protein ________________. a. minus end; dynein b. minus end; kinesin c. plus end; dynein d. plus end; kinesin

d. plus end; kinesin

In carboxylation, the enzyme ____________ adds a carbon from ____________ to ____________. a. rubisco; glucose; RuBP b. RuBP; glucose; rubisco c. RuBP; CO2; rubisco d. rubisco; CO2; RuBP

d. rubisco; CO2; RuBP

Noncompetitive inhibitors of a reaction will bind _________. a. to the substrate b. somewhere on the substrate other than at the active site c. to the active site of the enzyme d. somewhere on the enzyme that is not at the active site

d. somewhere on the enzyme that is not at the active site

In the pathway leading from threonine to isoleucine, threonine dehydratase is_______ by the presence of threonine. a. inhibited b. degraded c. caused to decrease in number d. caused to increase in number e. activated

e. activated

Which of the following statements are true regarding acetyl-CoA synthesis? a. this process occurs within the matrix of mitochondria b. this process constitutes the second stage of cellular respiration c. the process produces both CO2 and acetyl CoA d. the process yields no ATP via substrate-level phosphorylation e. all of the above

e. all of the above

Which of the following cytoskeletal filaments are capable of growing and shrinking in the cell? a. intermediate filaments b. microtubules c. microfilaments d. both a and b e. both b and c

e. both b and c

In cellular respiration, what is the final e- acceptor?

oxygen

______________ remove phosphates. _________________ add phosphates.

phosphatase kinase

Net G (ΔG) = G( ________________ ) - G( _________________).

products reactants

Chloroplasts store carbohydrates as ___________________.

starch

Describe two different ways in which ATP is generated in cellular respiration.

substrate level phosphorylation-ADP gets phosphorylated directly from another molecule oxidative phosphorylation-(ETC) ATP is generated indirectly(from electrons/H2O?)