bio chapter 5 done

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

transport proteins; down

In the lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?

water will leave the balloon

In a hypotonic solution, an animal cell will

lyse

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of

passive transport

The process of a white blood cell engulfing a bacterium (reaching out, grabbing, and pulling it in) is

phagocytosis

Most of a cell's enzymes are

proteins

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by

proteins

Which of the following statements regarding membrane protein function is false?

Membrane proteins transfer genetic information to the cytoplasm.

Which of the following statements regarding diffusion is false?

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

What is the basic difference between exergonic and endergonic reactions?

Exergonic reactions release energy; endergonic reactions absorb it.

Which of the following statements regarding membrane function is false?

The plasma membrane is the control center of the cell.

The energy required to overcome the energy barrier in an reaction is called

activation energy

Substrates bind to an enzyme's ________ site.

active

Which of the following processes can move a solute against its concentration gradient?

active transport

A plant cell in a hypotonic solution

becomes turgid because of an inflow of water

How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor?

competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.

The fluid mosaic model describes the plasma membrane as consisting of

diverse proteins embedded in a phospholipid bilayer.

When a cell uses chemical energy to perform work, it uses the energy released from a/an ________ reaction to drive a/an ________ reaction.

exergonic; endergonic

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place (solute CANNOT cross the membrane), the water will

exhibit a net movement to the side with lower free water concentration.

Certain cells that line the stomach make a digestive enzyme and secrete it outside the cell into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion?

exocytosis

The cholesterol associated with animal cell membranes

helps with regulating the fluidity of the membrane

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

is hypotonic to protozoan

A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be...

isotonic to its environment

Kinetic energy differs from chemical energy in that

kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.

Anything that prevents ATP formation will most likely

result in cell death

All cells are enclosed by a plasma membrane that is similar in ________ and ________.

structure; function

According to ________, energy cannot be created or destroyed.

the 1st law of thermodynamics

Osmosis can be defined as

the diffusion of water

Which of the following processes is endergonic?

the making of glucose from carbon dioxide and water (photosynthesis)

Plasma membranes are selectively permeable. This means that

the plasma membrane allows some substances to enter or leave a cell more easily than others.