Bs 161

How many hydrogen atoms are present in a hydrocarbon chain of five carbon atoms with two double bonds and two single bonds? 10 12 8 6

8

Three carbon atoms are linked by single covalent bonds such that they form the shape of a V. All of the unshared electrons form covalent bonds with hydrogen. How many hydrogen atoms does this molecule contain? 10 6 4 8 2

8

A beaker is divided by a membrane that is permeable to water and glucose, but not to sucrose. Equal volumes of solutions are added to side A and B with the initial concentrations as shown below. Initially, the liquid levels on both sides are the same. After the system described above reaches equilibrium, what can you predict about the water levels? Choice A., The water will be higher on side A than on side B. Choice B., The water will be higher on side B than on side A. Choice C., The water level will be the same on both sides.

A

As molecules move down their concentration gradient, from a more ordered state to a less ordered state, entropy: Question 1 choices Choice A., is increasing. Choice B., is decreasing. Choice C., remains the same.

A

During osmosis, water moves from a region of _____ to a region of _____. Both "high solvent concentration; low solvent concentration" AND "low solute concentration; high solute concentration" are correct answers. high solvent concentration; low solvent concentration low solute concentration; high solute concentration high solute concentration; low solute concentration

A

How do eukaryotic plant and animal cells differ from one another? Animal cells do not have chloroplasts and cell walls, and plant cells do. Animal cells have endoplasmic reticulum and plant cells don't. Animal cells have mitochondria but not chloroplasts, and plant cells have chloroplasts but not mitochondria. Animal cells have a plasma membrane and plant cells have a cell wall.

A

Which of the following eukaryotic cell structures plays a role in protein trafficking and sorting? the Golgi apparatus mitochondria lysosomes vacuoles the endoplasmic reticulum

A

The plasma membranes of some plant cells use transport proteins to move protons out of the cell against their concentration gradient (from areas of low proton concentration to areas of high proton concentration). This is an example of: active transport. passive transport. endocytosis. simple diffusion facilitated diffusion.

A

Which of the following CORRECTLY pairs the particles of an atom with their physical properties? proton-positively charged; neutron-uncharged; electron-negatively charged proton-uncharged; neutron-negatively charged; electron-positively charged proton-positively charged; neutron-negatively charged; electron-uncharged proton-negatively charged; neutron-uncharged; electron-positively charged

A

Which of the following is TRUE about exergonic reactions? Energy is released from the reactants. The products of exergonic reactions have more free energy than the reactants. There is a positive ΔG.

A

Which one of the following molecules would MOST likely require a transport protein to cross the plasma membrane of a red blood cell? C6H12O6 H2O CO2 O2

A

Why does active transport require ATP? An input of energy is needed to allow the movement of molecules from an area of low concentration to one of higher concentration. An input of energy is needed to speed up the rate of facilitated diffusion. An input of energy is needed to maintain the conformation of transport proteins. An input of energy is needed to both speed up the rate of facilitated diffusion and maintain the conformation of transport proteins.

A

Which of the following describes ATP hydrolysis? (Select all that apply.) exergonic spontaneous often coupled to a reaction that has a positive ΔG

A,B,C

A bacterial cell, a plant cell, and an animal cell have which of the following structures in common? nucleus cytoplasm nucleoid cell wall vacuole

B

Anabolic pathways of metabolism are pathways that: release stored chemical energy. build complex molecules from simple ones. make large quantities of ATP. take place primarily in skeletal muscle.

B

Energy input in the form of ATP is needed in which of the following processes? catabolism anabolism

B

If cells had single-layer membranes like micelles, how would the structures of transmembrane proteins be affected? Transmembrane proteins would only possess hydrophilic regions. Transmembrane proteins would possess a hydrophobic region in the cell interior and a hydrophilic region in the extracellular space. Transmembrane proteins would possess a hydrophilic region in the cell interior and a hydrophobic region in the extracellular space. Transmembrane proteins would only possess hydrophobic regions. The structures of transmembrane proteins would remain the same as if cells had lipid bilayers.

B

Molecules that are _____________BLANK and _____________BLANK are able to move across the cell membrane via simple diffusion. Question 3 choices Choice A., hydrophobic; large Choice B., hydrophobic; small Choice C., hydrophilic; large Choice D., hydrophilic; small

B

Simple diffusion of a molecule down its concentration gradient requires an input of energy to the system. Question 5 choices Choice A., true Choice B., false

B

The structural formula for hydrogen gas (H2) is represented as H―H. Here, the dash (―) represents a(n): electronegative bond. chemical bond. chemical reaction. product. reactant.

B

What kind of bond joins hydrogen to oxygen in a water molecule? Question 1 choices Choice A., hydrogen bond Choice B., polar covalent bond Choice C., nonpolar covalent bond Choice D., ionic bond

B

Why does ice float? Question 6 choices Choice A., If it was heavier than water, lakes would freeze from the bottom up. Choice B., The crystal lattice forces a less dense arrangement of molecules. Choice C., Other gases become trapped in the crystal lattice during freezing.

B

Which of the following reactions would you predict could be coupled to ATP synthesis from ADP + Pi? (Select all that apply.) glutamic acid + NH3 → glutamine, ΔG + 3.4 kcal/mol phosphoenolpyruvate + H2O → pyruvate + Pi, ΔG - 14.8 kcal/mol glucose 1-phosphate + H2O → glucose + Pi, ΔG - 5.0 kcal/mol glucose 6-phosphate + H2O → glucose + Pi, ΔG - 3.3 kcal/mol creatine phosphate + H2O → creatine + Pi, ΔG - 10.3 kcal/mol

B, E

A beaker is divided by a membrane that is permeable to water and glucose, but not to sucrose. Equal volumes of solutions are added to side A and B with the initial concentrations as shown below. Initially, the liquid levels on both sides are the same.After the system described above reaches equilibrium, what will be the concentration of glucose on side B? A., 1.0 M Choice B., 0.5 M Choice C., 0.75 M Choice D., The answer cannot be determined from the information provided.

C

All cells have: a cell wall. a nucleus. genetic information. internal compartments.

C

For an atom that is NOT an ion, which of the following must be TRUE? The number of electrons equals the number of neutrons. The number of protons equals the number of neutrons. The number of electrons equals the number of protons.

C

In an ice crystal, any single water molecule typically forms hydrogen bonds with how many other water molecules? Question 3 choices Choice A., 2 Choice B., 3 Choice C., 4 Choice D., 5 Choice E., 6

C

Sometimes, atoms gain or lose particles. The loss of which of the following results in a change of atomic mass? a proton an electron a neutron and a proton a proton and an electron a neutron

C

The interior region of a phospholipid bilayer is characterized as: hydrophilic. hydrophilic and polar. hydrophobic. polar.

C

The transition state is that portion of the progress of a chemical reaction with a large amount of energy found in ___________BLANK reactions. Question 1 choices Choice A., endergonic Choice B., exergonic Choice C., both endergonic and exergonic Choice D., nonspontaneous

C

The unique properties of water are due to the _____ of water molecules and the ability of water to form _____ with other water molecules and with other polar molecules. hydrophobicity; hydrogen bonds electronegativity; polar covalent bonds polarity; hydrogen bonds polarity; polar covalent bonds

C

What else is necessary in order for a hydrogen atom in a molecule to participate in a hydrogen bond? Question 5 choices Choice A., It must be part of a water molecule. Choice B., It must bond to a water molecule. Choice C., It must be bonded to a more electronegative atom. Choice D., It must not be bonded to an electronegative atom. Choice E., There must be another hydrogen atom.

C

Which of the following correctly describes the movement of water across a selectively permeable membrane during osmosis? Question 1 choices Choice A., The water will move from high water concentration to low water concentration. Choice B., The water will move from low solute concentration to high solute concentration. Choice C., Either of these descriptions is correct and equivalent.

C

woman's doctor tells her to gargle with salt water. She stirs a tablespoon of salt into a cup of warm water and watches it dissolve. Why does the salt dissolve in water? The negative oxygen atoms in water molecules are attracted to chlorine ions. The positive hydrogen atoms in water molecules are attracted to sodium ions. The positive hydrogen atoms in water molecules are attracted to chlorine ions, and the negative oxygen atoms in water molecules are attracted to sodium ions. The negative oxygen atoms in water molecules are attracted to sodium ions. The positive hydrogen atoms in water molecules are attracted to chlorine ions.

C

A container is divided into two compartments by a membrane that is fully permeable to water but not to larger molecules. Water is added to one side of the membrane (side A), and an equal volume of a 5% solution of glucose is added to the other (side B). What would you predict will happen? Question 3 choices Choice A., Glucose will diffuse from side A to side B. Choice B., Glucose will diffuse from side B to side A. Choice C., The water level on side A will increase and on side B will decrease. Choice D., The water level on side B will increase and on side A will decrease.

D

A polar bond is due to: equal sharing of valence electrons. the interaction between an ion and a non-ionic atom. None of the other answer options is correct uneven sharing of electrons in a covalent bond. an attraction of opposite charges.

D

A protein that is temporarily associated with a biological membrane is a(n): transmembrane protein and an integral membrane protein. integral membrane protein. transmembrane protein. peripheral membrane protein.

D

Gibbs free energy is defined as: the amount of potential energy in a system. spontaneous energy. the amount of energy lost as heat. the amount of energy available to do work. the amount of entropy.

D

Some plant cells take advantage of the high concentration of protons outside the cell to move solutes, such as sucrose, across the plasma membrane into the cell where the sucrose concentration is already relatively high. This type of transport is an example of: passive transport. facilitated diffusion. osmosis. secondary active transport.

D

Sometimes, atoms gain or lose particles. The loss of which of the following would result in a change of overall electrical charge? protons or neutrons protons only neutrons only protons or electrons electrons only neutrons or electrons

D

The hydrogen atoms in a water molecule have a ________ charge while the oxygen atom has a _________ charge. Question 2 choices Choice A., negative; positive Choice B., positive; negative Choice C., partial negative; partial positive Choice D., partial positive; partial negative

D

The lipid components of cellular membranes often include: phospholipids. phospholipids and fatty acids. fatty acids and cholesterol. phospholipids and cholesterol.

D

at will happen to the net movement of Waste molecules if the Na+/K+ Pump stops working? All net movement of Waste in or out of the cell will stop immediately Net movement of Waste out of the cell will stop immediately and then Waste will be transported into the cell Net movement of Waste out of the cell will continue indefinitely (nothing will change) Net movement of Waste out of the cell will continue for some time and then all net movement of Waste in or out of the cell will stop Net movement of Waste out of the cell will continue for some time and then Waste will be transported into the cell

D

A molecule of common table salt, or NaCl, is the result of _____ bond forming between a sodium (Na) atom and a chlorine (Cl) atom. a covalent a hydrogen a polar covalent either an ionic or a polar covalent an ionic

E

Water is able to dissolve many compounds as a result of which of the following? the fact that the hydrogen atoms in water molecules have a slight negative charge the fact that water molecules are nonpolar the fact that most nonwater molecules are hydrophobic the fact that water molecules are polar, and that the hydrogen atoms in water molecules have a slight negative charge the fact that water molecules are polar

E

Which of the following statements is TRUE regarding a polar molecule? A polar molecule is hydrophilic. A polar molecule is hydrophobic. A polar molecule will dissolve in water. A polar molecule will not dissolve in water. A polar molecule is hydrophilic and it will dissolve in water.

E

Water is neither hydrophilic nor hydrophobic, because these terms only define the interaction of other molecules with water molecules. False True

FALSE

REVIEW WEEK 1 PRACTICE QUIZ 2

SERIOUSLY DO IT NOW

At equilibrium, there will be no net movement of molecules across the cell membrane. Question 4 choices Choice A., true Choice B., false

a

If present in a molecule, which atom is least likely to participate in hydrogen bonds with water? Question 4 choices Choice A., hydrogen Choice B., carbon , Choice C., oxygen Choice D., nitrogen Choice E., sulfur

b

Phospholipase is an enzyme that cleaves the phosphate head group off a phospholipid molecule. The plasma membrane is not, however, permeable to the enzyme. Imagine a cell where phospholipid A is present in the layer of phospholipids facing the exterior of the cell, and phospholipid B is present in the layer of phospholipids facing the interior of the cell. After adding phospholipase to the medium in which the cell is growing, what would you expect to find in the fluid surrounding the cell? phosphate head groups from both phospholipids A and B the phosphate head group from phospholipid A only phosphate head groups from neither phospholipids A nor B the phosphate head group from phospholipid B only

b

Which eukaryotic organelle is associated with the breakdown of macromolecules? mitochondria lysosome endoplasmic reticulum the Golgi apparatus

b

Which of the following molecules does NOT easily diffuse across a plasma membrane? gases large polar molecules both small and large polar molecules

b

hich of the following examples is considered catabolism? (Select all that apply.) synthesis of new DNA copies prior to cell division use of fat (triglyceride) stores as a cellular energy source a person losing weight on a calorie restriction diet fat cells growing bigger during times of ample nutrition hydrolysis of glycogen (a glucose polymer) during activity

b,c,e

A container is divided into two compartments by a membrane that is fully permeable to water and small ions. Water is added to one side of the membrane (side A), and a 5% solution of sodium chloride (NaCl) is added to the other (side B). If allowed to reach equilibrium, which of the following would you predict? Question 2 choices Choice A., The level of solution on side A will be higher than side B. Choice B., The level of solution on side B will be higher than side A. Choice C., The NaCl concentration on side A and side B will each be 2.5%. Choice D., The NaCl concentration on side A and side B will each be 5%.

c

The random movement of molecules from areas of high concentration to low concentration is referred to as: transport. osmosis. diffusion. All of these choices are correct.

c

Which of the following is true about spontaneous chemical reactions? They require ATP to go to completion. The reactions have a positive change in free energy (+ΔG). The reactions are exergonic.

c

Refer to the periodic table, and decide which of the following molecules is held together by nonpolar covalent bonds. CH4 KCl NH3

ch4

Diffusion is best described as the random movement of molecules influenced by: Question 2 choices Choice A., the thermal energy of the environment. Choice B., energy transferred from molecular collisions in the cell. Choice C., the width of the plasma membrane of the cell. Choice D., the thermal energy of the environment and energy transferred from molecular collisions in the cell. Choice E., the thermal energy of the environment and the width of the plasma membrane.

d

Which one of the following is NOT a component of an animal cell's plasma membrane? lipid carbohydrate protein nucleic acid

d

If cells had single-layer membranes like micelles, how would the structures of transmembrane proteins be affected? Transmembrane proteins would only possess hydrophobic regions. Transmembrane proteins would possess a hydrophilic region in the cell interior and a hydrophobic region in the extracellular space. The structures of transmembrane proteins would remain the same as if cells had lipid bilayers. Transmembrane proteins would only possess hydrophilic regions. Transmembrane proteins would possess a hydrophobic region in the cell interior and a hydrophilic region in the extracellular space.

e

Refer to the periodic table, and decide which of the following molecules is held together by polar covalent bonds. CH4 NH3 KCl

nh3