Biology I Chapter 5 The Working Cell

A

Which of the following statements regarding diffusion is false? A) Diffusion is a result of the thermal energy of atoms and molecules B) Diffusion requires no input of energy into the system C) Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated D) Diffusion occurs even after equilibrium is reached and no net is apparent

D

Which of the following statements regarding membrane function is false A) The plasma membrane forms a selective barrier around the cell B) The plasma membrane plays a role in transferring signals to the cell's interior C) The plasma membrane has receptors for chemical messages D) The plasma membrane is the control center of the cell

C

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer? A) O^2 B) CO^2 C) Na^+ D) a small, nonpolar molecule such as butane (C^4H^10)

C

You are adrift in the Atlantic Ocean, and, being thirsty, drink the surrounding seawater. As a result, A) you quench your thirst B) your cells become turgid C) you dehydrate yourself D) your cells lyse from excessive water intake

A

A cell that has neither a net gain of water nor not loss of water when it is immersed in a solution must be A) isotonic to its environment B) hypertonic to its environment C) hypotonic to its environment D) metabolically inactive

B

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of A) exocytosis B) passive transport C) active transport D) endocytosis

B

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient A) energy and transport proteins; down B) transport proteins; down C) energy and transport proteins; against D) transport proteins; against

A

In a hypotonic solution, an animal cell will A) lyse B) experience turgor C) neither gain nor lose water D) shrivel

C

Kinetic energy differs from chemical energy in that A) kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement B) kinetic energy can be converted into various forms of energy, whereas chemical energy can only be converted into heat C) kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules D) chemical energy is a particular form of kinetic energy

A

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by glycolipids A) glycolipids B) proteins C) phospholipids D) cholesterol

D

Oxygen crosses a plasma membrane by? A) osmosis B) active transport C) pinocytosis D) passive transport

B

Phagocytosis is to eating is to A) osmosis B) drinking C) chewing D) lysis

B

Plasma membranes are selectively permeable. This means that A) anything can pass into or out of a cell as long as the membrane is intact and the cell is healthy B) the plasma membrane allows some substances to center or leave a cell more easily than others C) glucose cannot enter the cell D) plasma membranes must be very thick

A

Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell occurs when A) a signaling molecule binds to a protein that extends to the outside of the cell B) a protein receptor on the interior of the membrane become bounds by a signaling molecule C) the extracellular matrix is moved to the inside of the cell D) glycoproteins are recognized by other cells

A

Small, nonpolar, hydrophobic molecules such as fatty acids A) easily pass through a membrane's lipid bilayer B) very slowly diffuse through a membrane's lipid bilayer C) require transport proteins to pass through a membrane's lipids bilayer D) are actively transported across cell membranes

B

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment A) is isotonic to the protozoan B) is hypotonic to the protozoan C) contains a higher concentration of solutes than the protozoan D) is hypertonic to the protozoan

D

Substrats bind to an enzyme's _________ site A) allosteric B) inhibitory C) phosphate D) active

D

The fluid mosaic model describes the plasma membrane as consisting of A) a phospholipid bilayer with embedded carbohydrates B) two layers of phospholipids with cholesterol sandwiched between them C) carbohydrates and phospholipids that can drift in the membrane D) diverse proteins embedded in a phospholipid bilayer

D

The molecules responsible for membrane transport are A) steroids B) Phospholipids C) carbohydrates D) proteins

D

The process of a white blood cell engulfing a bacterium is A) osmosis B) receptor-mediated endocytosis C) pinocytosis D) phagocytosis

C

What is the basic difference between exergonic and endergonic reactions? A) Exergonic reactions involve ionic bonds; endergonic reactions involve covalent bonds B) Exergonic reactions involve the breaking of bonds; endergonic reactions involve the formation of bonds C) Exergonic reactions release energy; endergonic reactions absorb it D) In exergonic reactions, the reactants have less chemical energy than the products; in endergonic reactions, the opposite is true

A

When an enzyme catalyzes a reaction A) it lowers the activation energy of the reaction B) it raises the activation energy of the reaction C) it acts as a reactant D) It is used once and discarded

D

Which of the following direct energy transfers is impossible in living systems A) light energy to chemical energy B) chemical energy to kinetic energy C) light energy to potential energy D) heat to light energy

D

Which of the following is a typical feature of an ATP-driven active transport mechanism? A) The transport protein must be cross side of the membrane before the solute can bind to it B) The transport protein is irreversibly phosphorylated as transport takes place C) The transport protein catalyzes the conversion of ADP to ATP D) The solute moves against the concentration gradient

D

Which of the following processes can move a solute against its concentration gradient A) osmosis B) passive transport C) facilitated diffusion D) active transport

B

Which of the following processes is endergonic A) the burning wood B) the synthesis of glucose from carbon dioxide and water C) the breakdown of glucose D) cellular respiration

D

Which of the following statements about the ATP molecule is true A) It contains five phosphate groups B) Extremely stable bonds link the second and third phosphate groups C) It contains the sugar glucose D) It releases energy when one phosphate group leaves ATP

B

Which of the following statements regarding active transport is false? A) Active transport uses ATP as an energy source B) Active transport can move a solute against its concentration gradient C) Active transport requires the cell to expend energy D) Active transport is driven by the concentration gradient

B

A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which of the following statements offers the most logical explanation for this action? A) Elevated body temperature will increase reaction rates in the child's cells and overload the limited number of enzymes found in the cell. B) Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions. C) Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions. D) Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions

B

According to ______________, energy cannot be created or destroyed A) Aristotle's first principles B) the first law of thermodynamics C) the second law of thermodynamics D) the third law of thermodynamics

A

Aquaporins A) allow water to cross the plasma membrane via facilitated diffusion B) allow water to cross the plasma membrane against its concentration gradient C) allow for the active transport of water D) are found in all cells

B

Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion? A) endocytosis B) exocytosis C) diffusion D) pinocytosis