Cam Biology Ch 4

Osmosis

Diffusion of water through a selectively permeable membrane

C. dehydration by osmosis of water. At high tide, cells would be covered with seawater, which would tend to draw out water from them by osmosis. Please see section 4.5 for more information.

During high tide, a plant or animal would be at risk of A. bursting by osmosis of water. B. dehydration by facilitated diffusion of salts. C. dehydration by osmosis of water. D. bursting by active transport of salts. E. dehydration by active transport of salts.

A. The plant cell wall acts as a sort of buffer during times of osmotic stress. Please see section 4.5 for more information.

During low tide, a plant cell will have an advantage over an animal cell because of its A. cell wall. B. plasma membrane. C. chloroplasts. D. nucleus. E. mitochondria.

a. Dye will diffuse from where it is in high concentration out into pure water, where it is at low (zero) concentration to start. Please see section 4.5 for more information.

Dye placed at one end of a beaker of otherwise pure water will A. diffuse towards the other side. B. remain in place. C. slowly bleach. D. form crystals. E. No answer is correct.

Enzmes in nature are almost always proteins. Please see section 4.4 for more information.

Enzymes A. slow reactions so they occur correctly. B. are not necessary to sustain life in a cell. C. are not found in living organisms. D. are proteins in most cases. E. are carbohydrates in most cases.

C Enzymes have specific shapes into which reactants fit. Please see sectiion 4.4 for more information.

Enzymes speed chemical reactions by A. lowering the amount of reactants that are needed. B. maintaining temperature. C. lowering the energy required to start a chemical reaction. D. raising the temperature of the surroundings. E. supplying energy to the reaction process.

A. Enzymes' shapes help lower the energy needed to start reactions. Please see section 4.4 for more information.

Enzymes speed up reactions by lowering the activation energy of a reaction. This is analogous with A. reducing the force a ball needs to start rolling down a hill. B. increasing the height an apple will fall from a tree. C. blocking a flowing river with a dam to stop the flow. D. causing a snow storm in the middle of summer when temperatures are hot. E. All answers are correct.

chemical bonds and concentration gradients. Living things have potential energy stored in chemical bonds and in gradients, such as proton gradients in mitochondria. Please see section 4.1 for more information.

Examples of potential energy include

C. Water, like other substances, will move down a concentration gradient. Please see section 4.5 for more information.

If a cell contains 95% water in its cytoplasm and the environment surrounding the cell contains 90% water A. water will flow into the cell by osmosis. B. water will flow out of the cell by active transport. C. water will flow out of the cell by osmosis. D. water will flow into the cell by active transport. E. water will flow into the cell by facilitated diffusion.

A. They lack an enzyme to break down phenylalanine PKU results when phenylalanine cannot be properly and safely broken down. Please see section 4.4 for more information.

If you could create and introduce into cells a chemical that would very specifically denature enzymes involved in digesting phenylalanine, why would patients treated with this drug develop phenylketonuria? A. They lack an enzyme to break down phenylalanine. B. They lack an enzyme to produce phenylalanine. C. They produce too much phenylalanine. D. They lack an inhibitor of an enzyme to break down phenylalanine. E. They eat more phenylalanine than most people.

E. the tendency to increase disorder. Disorder, randomness, tends to increase in systems. Please see section 4.1 for more information.

If you drop a rubber ball and it does not bounce back to the height you dropped it from. This is consistent with A. conversion of entropy into potential energy. B. energy being neither created nor destroyed. C. conversion of kinetic energy into potential energy. D. conversion of kinetic energy into entropy. E. the tendency to increase disorder.

d Reduction and oxidation occur in the same reaction, thus the term "redox." Please see section 4.2 for more information.

If you had to grade an exam question about oxidation-reduction reactions, you would give the most points if a student said that they A. never occur at the same time. B. remove electrons from both molecules involved. C. remove protons from one molecule and join them to another molecule. D. occur simultaneously. E. remove oxygen from the cell.

D. Glucose contains a large amount of energy in its chemical binds, energy which is released by cellular respiration. Please see section 4.2 for more information.

If you were looking for a card describing the breakdown of glucose to carbon dioxide and water, you would look in a drawer labelled with what information? A. takes up energy, photosynthesis B. takes up energy, cellular respiration C. releases energy, photosynthesis D. releases energy, cellular respiration E. No answer is correct

D. Substrates are reactants which fit into an enzyme's active site. Please see section 4.4 for more information.

If you were working with a 3D model of an enzyme, and you had found a part representing a molecule that fits into the active site, you would have found something that is A. always a protein. B. an analog. C. always a carbohydrate. D. a substrate. E. always broken down by the enzyme

E

In the section "Investigating Life: Does Natural Selection Maintain Cystic Fibrosis?," if two carriers of the defective CFTR gene have a child, what is the probability that the child will have cystic fibrosis? A. 75% B. 50% C. 100% D. 0% E. 25%

A. The cell is now in a hypertonic solution.

In the section "Investigating Life: Does Natural Selection Maintain Cystic Fibrosis?," why does water leave the cell by osmosis after the active transport of chloride ions out of the cell by CFTR? A. The cell is now in a hypertonic solution. B. The cell is now in a hypotonic solution. C. The cell is now in an isotonic solution. D. The cell needs to regenerate the ATP used in active transport. E. The cell must pump out water to avoid bursting.

D. the energy in chemical bonds Chemical bond energy may have come from some kind of kinetic energy, but it is not itself kinetic energy. Please see section 4.1 for more information.

In which case is the energy involved farthest from being kinetic energy? A. heat B. light C. sound D. the energy in chemical bonds E. random molecular movement

B. Noncompetitive inhibitors bind other than at the enzyme's active site. Please see section 4.4 for more information.

Noncompetitive inhibition of enzymes A. occurs when a substance other than the correct substrate binds at the active site of an enzyme. B. occurs when a substance binds to an enzyme at a site away from the active site. C. occurs by denaturation of an enzyme. D. occurs by blocking the production of an enzyme. E. occurs when two enzymes bind together.

D. Carriers with one copy of the defective CFTR gene have increased resistance to cholera compared to those with no defective copies.

n the section "Investigating Life: Does Natural Selection Maintain Cystic Fibrosis?," 1 in 25 Caucasians is a carrier for the defective CFTR gene, making it the most common genetic disease in this population. Why are the frequency of defects in CFTR so common in caucasians? A. Carriers with one copy of the defective CFTR gene have decreased resistance to cholera compared to those with no defective copies. B. These individuals were exposed to cholera, causing mutations in their CFTR gene that can then be passed on to their children. C. Carriers will be more likely to have children who develop cystic fibrosis. D. Carriers with one copy of the defective CFTR gene have increased resistance to cholera compared to those with no defective copies. E. Only carriers would be able to survive exposure to cholera.

Reduction Reduction involves an atom or molecule having greater control of electrons. Please see section 4.2 for more information.

the gain of electrons by an atom or molecule.

D. ATP powers most reactions in cells where the reaction would otherwise not be spontaneous. Please see section 4.3 for more information

The CFTR receptor moves chloride ions out of a cell by active transport. This is an example of A. a reaction coupled with the production of ATP. B. an oxidation reaction. C. a reduction reaction. D. a reaction requiring the input of energy (ATP). E. equilibrium.

Calories Calories are a measure of energy related to heating potential. Kilocalories are the units commonly used to describe the energy in food. Please see section 4.1 for more information.

The amount of energy required to raise the temperature of one gram of water by one degree Celsius is a

C6H12O6. Glucose is a six carbon sugar. Please see section 4.2 for more information.

The chemical formula for glucose is

sunlight. The name "photosynthesis" literally means "to build up with light." Please see section 4.2 for more information.

The energy source that powers photosynthesis is

Oxidation

The loss of electrons from a substance involved in a redox reaction.

water and carbon dioxide. In photosynthesis, water and carbin dioxide are converted into oxygen gas and glucose. Please see section 4.2 for more information

The reactants of photosynthesis are

active site

The region of an enzyme that catalyzes reactions is called

E. The two organisms shown live and do biological work at different temperatures. Please see section 4.4 for more information.

The two data curves on the figure illustrate that A. temperature ranges are not the same for all enzyme activity. B. temperature is not related to enzyme efficiency. C. optimal temperature ranges are not the same for all enzymes. D. pH is not related to enzyme efficiency. E. All answers are correct.

A. Enzymes are designed to work at temperatures which correspond with temperatures experienced by the organisms in which those enzymes are found. Please see section 4.4 for more information.

The vertical drop slightly after the peak of each curve on the figure illustrates A. that enzymes will not work if temperatures are too hot (or too cold). B. an increased rate of reaction. C. a decreased temperature. D. that temperatures only affect enzymes up to a specific temperature. E. that enzymes are most efficient at cold temperatures.

C. exergonic

The wood in a match is made of cellulose, a polymer of glucose molecules. When you light the match heat and light are given off, indicating that a(n) ________ reaction is occurring. A. endergonic B. kinetic energy C. exergonic D. potential energy E. equilibrium

TRUE More reduced compounds have more electrons. Please see section 4.2 for more information.

True / False Questions Reduction is the gain of electrons.

FALSE Energy is conserved-it can neither be created not destroyed. Please see section 4.1 for more information.

True / False Questions 52. The chloroplasts in a plant's cells create energy.

True

True / False Questions A reason that some antibiotics harm bacteria, but not humans, is because the antibiotic inhibits bacterial enzymes that humans do not have.

FALSE Energy in living systems must be captured from source, living or non-living. Please see section 4.1 for more information.

True / False Questions Energy sometimes appears spontaneously in living systems.

False

True / False Questions Exergonic reactions do not require activation energy to get started because they release energy.

TRUE Oxidized molecules have lost some of their electrons. Please see section 4.2 for more information.

True / False Questions Oxidation is the loss of electrons.

FALSE Phagocytosis involves the powered uptake of particles containing nutrients. Please see section 4.5 for more information.

True / False Questions Phagocytosis is a process that cells primarily use to obtain nutrients.

TRUE The breakdown of ATP provides ample energy to power many cellular processes. Please see section 4.3 for more information.

True / False Questions The most common way for energy-absorbing reactions to be powered in cells is for them to be coupled with the breakdown of ATP.

TRUE A larger concentration gradient makes for a larger driving force and faster diffusion. Please see section 4.5 for more information.

True / False Questions When the concentration gradient driving osmosis becomes larger, osmosis occurs at a faster rate.

TRUE Any energy transfers in the physical universe, including those in living things, involve some loss of useful energy, some increase in entropy. Please see sections 4.1 and 4.3 for more information.

True / False Questions Whenever ATP is produced by a chemical reaction some energy is lost into the surroundings as heat.

FALSE Diffusion occurs down, or with, concentration gradients. Please see section 4.5 for more information.

True or False Diffusion occurs against concentration gradients.

TRUE Enzymes speed chemical reactions without themselves being used up in the reactions. Please see section 4.4 for more information.

True or False Enzymes speed up chemical reactions.

FALSE Potential energy is stored energy,while the energy of motion is kinetic energy. Please see section 4.1 for more information.

True or False Potential energy is the energy of motion.

FALSE Reactions which release energy are spontaneous on their own. Please see section 4.2 for more information.

True or False Reactions that take up energy proceed spontaneously.

True

True or false Coupled reactions involve one reaction that provides energy to the other.

A

When NaCl (table salt) forms, sodium (Na) loses energy by ______ and chlorine (Cl) gains energy by ______. A. giving up an electron in oxidation; gaining an electron in reduction B. going with its concentration gradient; going against its concentration gradient C. going against its concentration gradient; going with its concentration gradient D. gaining an electron in oxidation; by giving up an electron in reduction E. gaining an electron in reduction; giving up an electron in oxidation

oxidized Loss of control of electrons, as when they are removed, is oxidation. Please see sections 4.1 and 4.2 for more information.

When electrons are removed from a food molecule, the molecule is

A. Kinetic energy is the energy of motion. Please see section 4.1 for more information.

Which of the following are examples of kinetic energy? A. electrons moving through the electron transport chain, protons moving through ATP synthase B. electrons in chemical bonds, proton gradient, ATP C. electrons moving through the electron transport chain, proton gradient D. protons moving through ATP synthase, ATP E. All answers are correct.

B. Potetial energy is stored energy which may be used later. Please see section 4.1 for more information.

Which of the following are examples of potential energy? A. electrons moving through the electron transport chain, proton gradient B. electrons in chemical bonds, proton gradient, ATP C. protons moving through ATP synthase, ATP D. electrons moving through the electron transport chain, and protons moving through ATP synthase E. All answers are correct.

A. Turgor pressure occurs when enough water is taken up by cells with cell walls that the celular contents are pressurized and push against the wall. Please see section 4.5 for more information.

Which statement about turgor pressure would be marked wrong on an exam? A. It occurs in an organism with cell walls when placed into a hypertonic environment. B. It is necessary to keep plants from wilting. C. It is the force of water against the inside of the cell wall. D. It is maintained by osmosis. E. It occurs in an organism with cell walls when placed into a hypotonic environment

D. Any energy transformation loses some energy to its surroundings as heat. Energy can neither be created nor destroyed. Please see section 4.1 for more information.

Which statement is least directly connected with the law about energy being preserved? A. The amount of energy in the universe is constant. B. Energy cannot be created or destroyed. C. Energy can be converted to other forms of energy. D. Any energy transformation loses some energy to its surroundings as heat. E. None of the answers are correct.

potential energy; kinetic energy Potential energy is energy which may be used for some purpose, while kinetic energy is the energy of motion. Please see section 4.1 for more information

A ball at the top of a hill is an example of ______ and a ball rolling down the hill is an example of ______.

A. Enzymes speed the breakdown of glucose inside cells. Please see sections 4.1 and 4.4 for more information.

A bowl of sugar water is very stable. But if you feed it to cells then it is rapidly broken down into carbon dioxide, water, and ATP. What is the best explanation for this observation? A. Enzymes in the cell catalyze the breakdown of the glucose. B. Cells use energy to break down the glucose. C. Glucose becomes more chemically reactive inside of a cell. D. Glucose cannot be broken down outside of a cell. E. Glucose is removed from the cell by active transport.

Entropy

A measure of disorder or randomness.

E. All answers are correct. Active transport requires an input of energy and results in the creation of a concentration gradient. Please see section 4.5 for more information.

Active transport is different from simple diffusion because active transport A. requires energy. B. moves molecules against a concentration gradient. C. requires the use of proteins embedded within the cell membrane. D. moves molecules from an area of lower concentration to an area of higher concentration. E. All answers are correct.

E. can be recharged with the uptake of energy to form ATP. ATP is recharged by adding phosphate to ADP, adding energy at the same time. Please see section 4.3 for more information.

After ATP donates a phosphate group to a coupled reaction, then it becomes ADP. The ADP A. can be recharged with the release of energy to form ATP. B. is a waste product that will be broken down. C. can be recharged in an equilibrium reaction to form ATP. D. can be recharged in an oxidation reaction to form ATP. E. can be recharged with the uptake of energy to form ATP.

A. Competitive inhibitors compete with proper substrates for the active site. Please see section 4.4 for more information

Competitive inhibition of enzymes A. occurs when a substance other than the correct substrate binds at the active site of an enzyme. B. occurs when a substance binds to an enzyme at a site away from the active site. C. occurs by denaturation of an enzyme. D. occurs by blocking the production of an enzyme. E. occurs when two enzymes bind together.

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

A. potential energy. The energy in a meal of gazelle is potential energy. Please see section 4.1 for more information.

By eating a gazelle, a lion gains A. potential energy. B. kinetic energy. C. entropy. D. respiratory capacity. E. enzymes for digesting grass.

E. Cells use energy to power all of their basic functions. Please see section 4.1 for more information.

Cells use energy for which of the following? A. to do work B. to synthesize proteins C. to expel waste D. to move substances across membranes E. All answers are correct.

A Redox reactions involve the transfer of electrons. Please see section 4.2 for more information.

Oxidation-reduction reactions A. transfer electrons from one molecule to another. B. are not used by living cells. C. transfer protons from one molecule to another. D. reduce the amount of oxygen in the cell. E. increase the amount of oxygen in the cell.

C Photosynthesis puts the energy from absorbed light into the energy in chemical bonds. Please see section 4.2 for more information.

Plants require energy from light to perform photosynthesis in which glucose is formed from carbon dioxide and water. This is an example of A. a reaction that releases energy. B. kinetic energy. C. a reaction that takes up energy. D. potential energy. E. equilibrium.

E. the concentration gradient of salt or vinegar causes osmosis out of the food and the extreme salt or pH concentration denatures the proteins, including enzymes. Enzymes can be denatured by a range of factors, including pH and salt concentation, and denaturation destroys their activity. Please see section 4.4 for more information.

Salted and pickled foods can last unrefridgerated for many years because A. the extreme salt or pH concentration denatures the proteins, including enzymes. B. the concentration gradient of salt or vinegar causes osmosis into the food. C. equilibrium with the environment has occured. D. the concentration gradient of salt or vinegar causes osmosis out of the food. E. the concentration gradient of salt or vinegar causes osmosis out of the food and the extreme salt or pH concentration denatures the proteins, including enzymes.

E. does not require energy. Simple diffusion does not require any energy input. Please see section 4.5 for more information.

Simple diffusion A. requires energy. B. utilizes proteins to move molecules across a membrane. C. moves molecules against a concentration gradien t. D. cannot occur without a membrane present. E. does not require energy.

C. ATP is used to power the light-producing reactions in fireflies. Please see section 4.3 for more information.

Studies of fireflies show that as they produce light, they constantly recycle ATP. Why might this be? A. ATP breakdown releases light. B. ATP is light-sensitive. C. ATP powers light production in fireflies. D. Fireflies need ATP for other processes. E. No answer is correct.