Lesson 2.2 Review Q’s 10 points 1. Which form of energy is important for living

things? Why?2. What happens during photosynthesis?

Explain why the process is important.3. Explain how cellular respiration &

photosynthesis relate.4. What is the process called when cells

release energy without oxygen? What are the 2 types?

5. Why do your muscles hurt when you play/run hard for long periods of time?

Lesson 2.3; T.O.C.:Materials Move Across

the Cell Membrane

NOTES HEADING:

How Materials MoveWhat happens when you spray air freshener in 1 corner of a room?

Diffusion(w.w)- molecules spreading out◦ They move from an area of high concentration to

low◦ The greater the difference in concentration the

more rapidly diffusion occurs. Gradually slows while spreads.

◦ Basically- particles spread out naturally & evenly to the rest of an area while moving further apart b/c molecules in gases/liquids/solids are constantly in motion in all directions. Particles are always in motion.

◦ Cells use diffusion to carry out important life functions & maintain conditions necessary for life Ex: O2 in/CO2 out

Some Materials Move by: Diffusion

In the Labs/Activities section of your Notebook make a new heading: “Vinegar & Egg’s ‘Awe’smosis Adventure” ~ Also featuring Diffusion, Dissolution & Active Transport

LAB

One way materials move in/out of cells.◦ EX: O2 defuses out of plant cell. ◦ Passive Transport(w.w)- materials move w/out

using cells energy.◦ How well material moves thru depends on how

well the substance dissolves in lipids.◦ Other polar substances, like glucose, salts, &

amino acids, move through Protein channels-gates- specific for each substance. ↑ Pretty cool since all cells

need the food energy supplied by glucose!

Diffusion in Cells

Diffusion of water thru a membrane.◦ Cells need water too, this is how they

get fresh H2O◦ If concentration of water is higher outside a cell

than inside; the water will move inside. If lower outside than in, water moves out.

◦ Another form of passive transportation◦ Some ~LAB!!~◦ In your Science Notebook: Labs & Activities section:

On top of page make the heading: “Grow a Gummy”

Osmosis(W.W)

When materials seem to move backward from areas of low concentration to high concentration

Active Transport- using energy to move materials through a membrane. ◦ Cells use this during important life functions such as

removal of excess salt. Cells in your kidneys filter excess salt from blood cells by active transport.

* DNW….sometimes cells need/have materials that are too big to pass through the cell membrane/protein channel….

Some Transport Requires Energy

When cells need materials that are too big to go thru the cell membrane or protein channel1. Material is captured within a pocket of the cell

membrane.2. Cell membrane begins to form a ring around the

captured material to bring it inside the cell. 3. The “package” breaks away from membrane &

moves inside the cell.

Endocytosis (w.w)

When cells need to get rid of large molecules that are too large to pass thru the cell membrane or protein channel.1. Membrane within cell encloses molecule(s) that

needs removes & forms a package which moves toward the side of cell.

2. Package attaches to the side of cell & begins to become part of the cell membrane.

3. Molecule(s) are pushed out as the “package” membrane finishes becoming part of the cell membrane.

Exocytosis (w.w)

If cells weren’t so tiny they wouldn’t be able to do their jobs.

The relationship between surface area & volume controls cell size.

Cell size and shape affect surface area/volume

By being so tiny cells can perform their jobs more efficiently by being faster than if they were bigger.

How can something as important as a cell be so tiny?

1. How are the processes of diffusion & osmosis alike?

2. What is the difference between active & passive transport? Use the word “energy” in your answer.

3. What is the function of protein channels?4. What is the difference between

endocytosis and exocytosis? 5. How do cells get rid of salt?

2.3 Review Questions 10 points