Chapter 3 Section 4Looking Inside Cells

Big Idea

California StandardsScience Standard 7.1.a:

Students know cells function similarly in all living organisms.

Paraphrase:

Cells function similarly in all living organisms. Open to page 102

Looking Inside CellsBig Idea

Inputselectively permeable: A property of cell membranes that

allows some substances to pass through, while others cannot.

diffusion: The process by with molecules move from an area of higher concentration to an area of lower concentration.

osmosis: The diffusion of water molecules through a selectively permeable membrane.

passive transport: The movement of material through a cell membrane without using the cell’s energy.

active transport: The movement of material through a cell membrane using the cell’s energy.

Input

If two solutions of different concentration are separated by a semi-permeable membrane which is permeable to to the smaller solvent molecules but not to the larger solute molecules, then the solvent will tend to diffuse across the membrane from the less concentrated to the more concentrated solution. This process is called osmosis. Osmosis is of great importance in biological processes where the solvent is water. The transport of water and other molecules across biological membranes is essential to many processes in living organisms.

Write at least 3-5 facts about the following video:

Osmosis

Summary:

Input: Science Standard 7.1.b and RC 2.1

Active Transport Passive Transport

Requires energy No energy required

Material moves in andout.

Unanswered QuestionsWrite down two questions you have about this

chapter!

Different PerspectivesPassive Transport: Materials pass through the cell

membrane without using any energy. This is like when you ride a bike and you start down a hill and

there is no need to pedal because gravity is pulling you down.

This can be in diffusion and osmosis

Active Transport: Transport proteins move material across the membrane using the cell’s energy. This is when you are pedaling up a hill. It is slow and you

have to work hard so you have to use a lot of your own energy.

When the cell needs to take in something from higher concentration.

Patterns Diffusion-

Move from high concentration to lower concentration

Independent Practice

“The Cell in its Environment” Worksheet #1-112