Chapter 9, Lesson 4 - The Cell In Its Environment

Cells must let certain materials enter and exit.

• True

• False

Which of these substances would most likely need to leave our cells?

• Oxygen

• Carbon dioxide

• Water

• Food particles

The cell membrane is mostly made up of a double layer of ___ molecules.

• Nucleic acid

• Carbohydrate

• Protein

• Lipid

The cell membrane has some ___ found on the double layer of lipids

• Carbohydrates only

• Proteins only

• Carbohydrates and proteins

• Nucleic acids

Since the cell membrane allows some substances to cross but keeps others out, we say it is ___ permeable.

• somewhat

• kinda

• selectively

• sort of

What are the two MAIN ways materials pass through the membrane?

• Diffusion and osmosis

• Passive transport and active transport

• Exocytosis and endocytosis

• Facilitated diffusion and active transport

The cell needs to use energy to make passive transport happen.

• True

• False

In diffusion, molecules move from areas of __ concentration to __ concentration.

• low, high

• high, low

• low, low

• high, high

Which substance is most likely to go through a cell membrane by diffusion?

• Oxygen

• Sugar

• Large food particles

• Sodium

Osmosis is the same process as diffusion, but specifically for this substance:

• Carbon dioxide

• Oxygen

• Water

• Sugar