Mastering Biology: Cell Membranes and Transport 11/14

Which statement best describes phagocytosis?

A cell engulfs a particle by wrapping pseudopodia around it and packaging it within a vacuole.

Which of the following is an accurate comparison of active transport and facilitated diffusion?

Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.

Which of the following is a difference between active transport and facilitated diffusion?

Active transport requires the expenditure of cellular energy, and facilitated diffusion does not.

Green olives may be preserved in brine, which is a 20-30% salt solution. How does this method prevent contamination by microorganisms?

Bacteria can't survive in a hypertonic solution because they lose water.

The diffusion of water across a selectively permeable membrane is called _____.

Osmosis

What name is given to the process by which water crosses a selectively permeable membrane?

Osmosis

_ is the passive transport of water

Osmosis

The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?

a hypertonic sucrose solution

The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of exocytosis. passive transport. facilitated diffusion. active transport. diffusion.

active transport

Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____.

actively pump water back into their cells to counter its loss due to osmosis

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of diffusion. passive transport. endocytosis. exocytosis. active transport.

endocytosis.

Lipid soluble molecules are _

hydrophobic.

If the volume of a cell increases when it is placed in an aqueous solution, that solution is said to be _____ to the cell.

hypotonic

A cell will _ water when placed in a hypertonic solution.

lose

Which one of the following terms specifically refers to the intake of very large particles by cells? phagocytosis exocytosis pseudocytosis osmosis pinocytosis

phagocytosis

Seawater is dangerous to drink because _____.

sea water is hypertonic to your body tissues and drinking it will cause you to lose water by osmosis

Water crosses the plasma membrane through active transport. using a process that requires energy from the cell. through cotransport. against its concentration gradient. through facilitated diffusion or diffusion

through facilitated diffusion or diffusion.

In a hypotonic solution plant cells experience a net gain of water and become _

turgid

Which of these statements describes what occurs in facilitated diffusion? - Facilitated diffusion is another name for osmosis. -Facilitated diffusion of solutes occurs through phospholipid pores in the membrane. - Facilitated diffusion requires energy from the cell to drive a concentration gradient. -Facilitated diffusion of solutes occurs through protein pores in the membrane. - There is only one kind of protein pore for facilitated diffusion.

Facilitated diffusion of solutes occurs through protein pores in the membrane.

A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of facilitated diffusion. exocytosis. diffusion. active transport. endocytosis.

facilitated diffusion

A cell will _ water when placed in a hypotonic solution

gain

In active transport, - a vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell. -molecules move across the plasma membrane against their concentration gradient. -the plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. -no energy input is required from the cell. -molecules move across the plasma membrane by crossing the lipid bilayer directly, rather than by using a transport protein.

molecules move across the plasma membrane against their concentration gradient.

You're on the pilot episode of a new reality show called "The Transport Factor." The host hands you three different amino acids, four different sugars, and two different ions. Then the host shouts, "How many different proteins does the cell need to move these molecules across the plasma membrane using facilitated transport?" Quickly, you correctly respond: _____.

nine

When placed in a hypotonic environment, where the solute concentration is below that of the cell, a houseplant will _____.

remain standing upright