Cell Transport and Membranes

A student noticed that placing wilted lettuce in a bowl of cool water caused the lettuce to become more crisp and firm. What is the best explanation for his observation?

• Water moved into the lettuce cells by active transport.

• Water moved into the lettuce cells by osmosis.

• Salt moved into the lettuce cells by diffusion.

• Water moved out of the lettuce cells by osmosis.

Tags

NGSS.MS-LS1-2

_______ regulates what enters and leaves a cell.  

• Cell Membrane

• Nucleus

• Mitochondria

• Cytoplasm

Tags

NGSS.MS-LS1-2

Identify cholesterol molecule

• structure a

• structure b

• structure h

• structure i

Identify a peripheral protein

• structure a

• strucure b

• structure g

• structure h

Which is NOT a function of the membrane?

• it forms a selective barrier

• it has receptors for chemical messages

• it is the control center of the cell

• it is involved in self recognition

Membrane phospholipids

• have hydrophobic heads that face the center of the membrane and are shielded from water

• have hydrophilic tails that face outward

• remain fluid because they are tightly packed

• none of these

The cholesterol associated with membranes

• is attached to proteins and extends into the environment surrounding the cell

• helps stabilize the membrane at body temperature

• is an abnormality resulting from a diet high in cholesterol

• both a and c

Which of the following would likely move through the lipid bilayer most rapidly?

• potassium

• an amino acid

• Carbon dioxide

• glucose

What is the "big idea" of the Fluid Mosaic Model of plasma membranes?

• the plasma membrane creates a specialized FLUID that looks like a MOSAIC.

• the plasma membrane is a MOSAIC.

• the fluid mosaic model is NOT related to the plasma membrane.

• a plasma membrane is a MOSAIC of components that move FREELY and FLUIDLY.

Describes the arrangement of the cell membrane as bendable and made of many parts.

• the fluid mosaic model

• the major mobility model

• the crazy cell model

• the cell theroy model

Tags

NGSS.MS-LS1-2