BIL Exam 3

If large numbers of ribosomes are present in the cytoplasm of a cell, then the cell is likely to specialize in producing which of the following cellular molecules?
A) Glycogen

B) Cellulose

C) Lipids

D) Proteins

E) Nucleic Acids

Proteins

Which of the following organelles or structure is primarily involved in the synthesis of lipids, bile, and drug detoxification?

A) Lysosome

B) Ribosome

C) Contractile vacuole

D) Rough endoplasmic reticulum

E) Smooth endoplasmic reticulum

Smooth endoplasmic reticulum

The Golgi apparatus has a polarity or sidedness to its structure and function. Which of the following statements correctly describes this polarity?

A) transport vesicles fuse with one side of the Golgi and leave from the opposite side

B) Proteins in the Golgi may be sorter and modified as they move from an opposite side of the Golgi to the other

C) Carbohydrates on proteins in the GOlgi may be modified and/or sorted as they move from one side of the Golgi to the other

D) Transport vesicles leave the Golgi on the “trans” side

E) All of the above correctly describe polar characteristics of the Golgi function

All of the above correctly describe polar characteristics of the Golgi function

Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components. Which of the following organelles contains such hydrolytic enzymes in plant cells?

A) Peroxisome

B) Central Vacuole

C) Chloroplast

D) Smooth endoplasmic reticulum

Central vacuole

One of the key innovations in the evolution of eukaryotes from a prokaryotic ancestor is the endomembrane system. Which of the following gives rise to and/or is a significant part of this endomembrane system?

A) Chloroplast membranes

B) Outer Nuclear Membrane

C) Plasma Membrane

D) Mitochondria Cristae Membranes

E) Ribosomal Membranes

Outer nuclear membrane

Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?

A) Sites of energy production in cellular respiration

B) Ribosomes

C) Cellulose fibers in the plant cell wall

D) Cell membrane bound proteins

E) Cytoskeletal proteins and structures

Cytoskeletal proteins and structures

Which of the following statements about the cytoskeleton is a false statement?

A) Cytoskeletal function is made possible by the assembly and disassembly of a globular cellular proteins into complex aggregates

B) The smooth endoplasmic reticulum is responsible for the assembly of the cytoskeleton

C) Chemicals that block the assembly of the cytoskeleton could result in the loss of cellular shape

D) Movement of the cilia and flagella is the result of motor proteins causing microtubules to move relative to each other

E) Microtubules are mostly rigid and resist compression, whereas microfilaments provide tension

The smooth endoplasmic reticulum is responsible for the assembly of the cytoskeleton

Plasmodesma in plant cells are most similar in function to which of the following structures in animal cells?

A) Peroxisomes

B) Gap junctions

C) The extracellular matrix

D) Desmosomes

E) Tight Junctions

Gap junctions

Of the following what is the most likely pathway taken by a newly synthesised protein that will be secreted by an animal cell?

A) Golgi -> ER -> lysosome

B) ER -> lysosomes -> vesicles that fuse with nuclear membrane

C) nucleus -> ER -> Golgi

D) ER -> Golgi -> vesicles that fuse with a cell's plasma membrane

E) ER -> Golgi -> nucleus

ER -> golgi -> vesicles that fuse with a cell's plasma membrane

Which of the following processes would likely include all other processes?

A) Osmosis

B) Diffusion of a solute across a membrane

C) Passive transport

D) Movement of an ion down a concentration gradient through a channel protein

E) Facilitated diffusion

Passive transport

Which of the following factors would most likely lead to increase membrane fluidity?

A) A relatively low protein content in the membrane

B) A lower temperature

C) A greater proportion of unsaturated phospholipids

D) A greater proportion of saturated phospholipids

E) A greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses

A greater proportion of unsaturated phospholipids

You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that might best determine whether your molecule could selectively enter into these target cells?

A) Lack of charge on the drug molecules

B) Hydrophilicity of the drug molecule

C) A high hydrophobicity of the drug molecule

D) Lipid composition of the target cells’ plasma membrane

E) Blood or tissue type of the patient

A high hydrophobicity of the drug molecule

A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, an equal volume of distilled water to the amount of blood loss is transferred directly into one of her veins. What will be the most probable?

A) The patients red blood cells will swell because the blood fluid has become hydroponic compared to the cells

B) The patients red blood cells will shrivel up because the blood fluid is isotonic compared to the cells

C) It will have no unfavorable effect as long as the water is free of viruses and bacteria

D) The patients red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells

E) The patients red blood cells will burst because of the change of temperature of the blood

The patients red blood cells will swell because the blood fluid has become hydroponic compared to the cells

Which of the following membrane activities requires energy from ATP hydrolysis?

A) Movement of water into a cell

B) Movement of solute molecules into a bacterial cell from a medium containing a higher concentration of the solute than inside the bacterial cell

C) Na+ ions moving out of a mammalian cell

D) Movement of carbon dioxide out of a paramecium

E) Facilitated diffusion of chloride ions across the membrane through a chloride channel

Na+ ions moving out of a mammalian cell

Water passes quickly through membranes because?

A) It moved through aquaporin proteins in the membrane

B) The membrane bilayer is hydrophilic

C) It moved through hydrophobic channel proteins

D) It is a small, polar, charged molecule

E) Water movement is tied to ATP hydrolysis

It moved through aquaporin proteins in the membrane

Which of the following is a characteristic feature of a carrier protein in a cell membrane?

A) It is a peripheral (extrinsic) membrane protein

B) It exhibits a specificity for a certain type of molecule

C) It always required the expenditure of cellular energy to function

D) It always works against the diffusion gradient

E) It has few, if any, hydrophobic amino acids

It exhibits a specificity for a certain type of molecule

Cell membranes are structurally asymmetrical. Which of the following may be a most likely explanation for this asymmetry?

A) The cell membrane forms. border between one cell and another in tightly packed tissues such as epithelial cell lining the gut

B) The “innerness” and “outerness” of membrane surfaces are predetermined by special gened

C) The two sides of the membrane face different environments so they may carry out different functions on each side

D) Proteins can only be associated with the cell membranes on the cytoplasmic sides.

E) Cell membranes communicate signals from one organism to another

The two sides of the membrane face different environments so they may carry out different functions on each side

According to the fluid mosaic model of cell membranes, which of the following is a correct statement about the cell membrane phospholipids?

A) They are free to depart from the membrane and dissolve in the surrounding solution

B) They have hydrophilic tails in the interior of a membrane bilayer

C) They occur only on the cytoplasmic side of a cell membrane

D) They may move laterally along the plane of the membrane

E) They constantly flip-flop from one side of the membrane to the other

They may move laterally along the plane of the membrane

If a pharmaceutical company wishes to design a drug to block the interaction between a G-protein receptor and an intracellular G-protein, then their drug should best block which of the following?

A) The bringing of the G-protein to the exterior (exoplasmic) side of the receptor molecule

B) cAMP binding to the G-protein

C) The phospholipids of the cell’s membrane bringing a G-protein

D) The binding site of the G-protein coupled receptor for the G protein

E) The binding site for the enzymes undergoing transduction

The binding site of the G-protein coupled receptor for the G protein

Which of the following types of signaling communication is represented in the figure?

A) hormonal

B) long distance

C) endocrine

D) paracrine

E) mating signaling

paracrine

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following would provide evidence that this is related to cell signaling?

A) That enzymatic activity of glycolysis increases

B) Growth factor signals do not bind as efficiently to their receptors as previously

C) that cAMP levels never change

D) That lower glucose concentrations elicit a greater response

E) That ATP production increases

Growth factor signals do not bind as efficiently to their receptors as previously

GTPase activity is involved in the regulation of signal transduction because it?

A) Phosphorylates protein kinases

B) Decreases the amount of G-protein in the membrane

C) Hydrolases the GTP bound to a G-protein

D) Converts cGMP to GTP

E) Increases the available concentration of phosphate

Hydrolases the GTP bound to a G-protein

At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?

A) Because estrogen binds to specific receptors on many different kinds of cells, many of which have different responses to its binding

B) Because estrogen is produced in very large concentrations and therefore diffuses widely

C) Because estrogen synthesis stops cell metabolism

D) Because estrogen is kept away from the surface of membranes and therefore is not able to bind at the cell’s surface

E) Because every cell responds in the same way to the binding of estrogens

Because estrogen binds to specific receptors on many different kinds of cells, many of which have different responses to its binding

Signal molecules can result in a phosphorylation cascade by?

A) Inhibiting the action of a protein kinase enzyme

B) Binding of a hormone to a nuclear membrane receptor

C) Inhibiting the Na pump (NaK-ATPase)

D) Initiating conformational changes in a series of many different proteins

E) Altering the length of microtubular cilia proteins

Initiating conformational changes in a series of many different proteins

If an enzyme is added to a solution where the substrate and product of its reaction are in equilibrium, what will occur?

A) Additional substrate will be formed

B) Additional product will be formed

C) The free energy of the system will change

D) Nothing, the reaction will stay at equilibrium

E) The reaction will change from endergonic to exergonic

Nothing, the reaction will stay at equilibrium

Choose the pair of terms below that correctly correlates with this sentence: Catabolism is to anabolism as ________________ is to ________________.

A) entropy - enthalpy

B) exergonic - spontaneous

C) free energy - equilibrium

D) exergonic - endergonic

E) order - disorder

exergonic - endergonic

During a chemical reaction, you determine that the conversion of A to B by an ezyme has a ∆G0' of -20kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G0' for the new reaction?

A) +20 kcal/mol

B) -20 kcal/mol

C) +40 kcal/mol

D) 0 kcal/mol

E) -40 kcal/mol

-20 kcal/mol

In glycolysis, for each molecule of glucose oxidized to pyruvate?

A) two molecules of ATP are consumed and thirty-six molecules of ATP are produced

B) two molecules of ATP are consumed and two molecules of ATP are produced

C) two molecules of ATP are consumed and four molecules of ATP are produced

D) thirty-six molecules of ATP are consumed and six molecules of ATP are produced

E) four molecules of ATP are consumed and two molecules of ATP are produced

two molecules of ATP are consumed and four molecules of ATP are produced

A primary function of the "shuttles" in aerobic cellular respiration seems to be to?

A) Directly reduce CO2

B) Move ATP into the mitochondria

C) Transfer captured electron energy into the mitochondria for use in the electron transfer chain

D) Produce lactic acid via fermentation

E) Hydrolyze ATP to ADP + P

Transfer captured electron energy into the mitochondria for use in the electron transfer chain

Among the differences in free energy between all the cellular ribonucleotides ATP, TTP, CTP, GTP, and UTP is?

A) That there is no difference in the free energy content of all these ribonucleotides

B) That only UTP can occur in cyclic configuration, as c-UMP

C) That there is no nitrogen-containing bases in TTP and UTP

D) That the number of phosphates in GTP and ATP is different than in TTP, CTP, and UTP

E) That the sugar molecule is different in all of them

That there is no difference in the free energy content of all these ribonucleotides

The mathematical expression that describes the change in free energy of a chemical system is ∆G= ∆H-T∆S. Which of the following statements is correct concerning the free energy equation?

A) ∆S is the change in enthalpy, a measure of the change in heat content

B) ∆H, the change in entropy, a measure in the degree of randomness of a reaction

C) ∆G is the change in the degree of order in a reaction

D) ∆H, the change in enthalpy of a reaction, is negligible in cellular reactions

E) ∆G, the change in free energy, is always a positive (+) value in cellular reactions

∆H, the change in enthalpy of a reaction, is negligible in cellular reactions

The ATP made during glycolysis is generated by?

A) Photophosphorylation

B) Oxidation of NADH to NAD+

C) Chemiosmosis

D) Electron Transport

E) Substrate-level phosphorylation

Substrate-level phosphorylation

The oxygen that is consumed during cellular respiration is involved directly in which of the following processes or events?

A) The citric acid cycle

B) glycolysis

C) The oxidation of pyruvate to acetyl CoA

D) The phosphorylation of ADP to form ATP

E) Accepting electrons at the end of the electron transport chain

Accepting electrons at the end of the electron transport chain

During aerobic cellular respiration electrons travel downhill in which of the following sequences?

A) food->citric acid cycle->ATP->NAD+

B) glucose->pyruvate->ATP->oxygen

C) food->glycolysis->citric acid cycle->ATP->NADPH

D) glucose->ATP->electron transport chain->NADH

E) food->NADH->electron transport chain->oxygen

food->NADH->electron transport chain->oxygen

When electrons flow along the electron transport chains in the mitochondria, which of the following changes occurs?

A) The cytochromes phosphorylate ADP directly to form ATP

B) NADP+ is oxidized

C) ATP synthase pumps protons out of the mitoplasm by active transport

D) The pH value of the matrix (mitoplasm) will increase

E) The electrons gain in free energy

The pH value of the matrix (mitoplasm) will increase

Most CO2 that is released during cellular respiration is released during which of the following processes?

A) Lactase fermentation

B) The krebs citric acid cycle

C) Oxidative phosphorylation

D) Electron transport

E) Glycolysis

The krebs citric acid cycle

In the Krebs citric acid cycle reaction shown, which of the following reactions is taking place?

A) Acylation

B) Oxidation/reduction

C) Decarboxylation

D) Choose this choice if all of the above occur during the reaction

E) Choose this choice if only two of the above occur during this Krebs cycle reaction

Choose this choice if all of the above occur during the reaction

In biochemical mechanisms, photophosphorylation in plants is most similar to which of the following?

A) Substrate level phosphorylation in the Krebs cycle

B) Oxidative phosphorylation in mitochondria

C) The Calvin Cycle

D) Carbon dioxide reaction in mitochondria

E) The reduction of NAD+

Oxidative phosphorylation in mitochondria

Which of the following sequences best represents the flow of electrons during green plant photosynthesis?

A) NADPH->chlorophyll-P680->Calvin Cycle

B) NADPH->electron transport chain->O2

C) H2O->PSII->ETC->PSI->NADPH

D) photosystem I->photosystem II->H2O

E) NADPH->O2->CO2->ETC

H2O->PSII->ETC->PSI->NADPH

A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations will be in the flask with algae compared to the control flask.

A) The dissolved oxygen in the flask with algae will always be higher

B) The dissolved oxygen in the flask with algae will not be different from the control flask at any time

C) The dissolved oxygen in the flask with algae will be higher in the light, but the same in the dark

D) The dissolved oxygen in the flask with algae will be higher in the light, but lower in in the dark

E) The dissolved oxygen in the flask with algae will always be lower

The dissolved oxygen in the flask with algae will be higher in the light, but lower in in the dark

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where is it likely that the extra ATP molecules came from?

A) non-cyclic photophosphorylation electron flow

B) the Calvin cycle

C) photosystem II

D) cyclic photophosphorylation electron flow

E) photosystem I

cyclic photophosphorylation electron flow

C4 plants and CAM (Crassuleacan Acid Metabolism) plants each lower the effects of photorespiration by?

A) Inhibiting the action of the enzyme PEP carboxylase (phosphoenol-pyruvate carboxylase)

B) Keeping these plants stomates open at all times to prevent low CO2 levels

C) A special carrier protein that prevents the entrance of oxygen into leaves

D) Altering the shape of Rubisco so it cannot bind oxygen

E) Storing CO2 in acid molecules as OAA that can be used at other times or in other cells

Storing CO2 in acid molecules as OAA that can be used at other times or in other cells

The enzyme(s) of carbon dioxide fixation (reduction) in photosynthesis in plants is (are)?

A) Ribulose-bisphosphate-carboxylase/oxygenase (Rubisco)

B) PEP-carboxylase (phosphoenol-pyruvate-carboxylase)

C) Both ribulose-bisphosphate-carboxylase /oxygenase (rubisco) and PEP carboxylase (phosphoenol-pyruvate carboxylase)

D) Carbonic anhydrase

E) Mitochondrial oxygenase

Both ribulose-bisphosphate-carboxylase /oxygenase (rubisco) and PEP carboxylase (phosphoenol-pyruvate carboxylase)