Homeostasis & Transport - Module A

The cell membrane is made of two layers of ______ which makes it a bilayer with each part consisting of a head and two fatty acid tails.

• Carbohydrates

• Proteins

• Phospholipids

• Cholesterol

How does a cell maintain homeostasis?

• has protein channels to allow materials in and out

• is a fluid mosaic model consisting of carbs, lipids, and proteins

• has a cell wall for protection

• both the cell wall and the lysosome protects the cell

Tags

NGSS.HS-LS1-3

What material forms the channels and pumps in the phospholipid bilayer?

• carbohydrates

• proteins

• hydrophilic heads

• lipids

Which way will the water molecules move during osmosis? The dashed line is the cell membrane. The mickey mouse heads represent a water molecule.

• Out of the cell, so the cell shrinks.

• Out of the cell, so the cell swells.

• Into the cell, so the cell shrinks.

• Into the cell, so the cell swells.

Tags

NGSS.HS-LS1-3

Osmosis is ______.

• the diffusion of water molecules through a semi-permeable mebrane from an area of low concentration to an area of high concentration

• the diffusion of particles from an area of high concentration to an area of low concentration

• the diffusion of water molecules through a semi-permeable membrane from an area of high concentration to an area of low concentration

• the diffusion of particles from an area of low concentration to an area of high concentration

During diffusion ______.

• substances moves from high to low concentration

• water moves when energy is used

• large or oddly shaped molecules move across a cell membrane

• water moves from high to low concentration

Something is ___________ ____________ when some molecules can cross the membrane while others cannot.

• selectively permeable

• really small

• anaerobic respiration

• actively transported

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.

Active transport requires energy because ______.

• The cell is moving something against a concentration gradient

• The cell is moving something with a concentration gradient

• All items need energy to move across a membrane

• Because materials are going through a protein channel

The picture is an example of ______. The arrow indicates the direction the solute is moving.

• active tranport

• passive transport

• diffusion

• osmosis