B.4(B) Lesson Cell Transport and Homeostasis

Cell membrane

The cell membrane is on the outside of the cell and is like the body guard of the cell. It controls what molecules can enter and exit the cell.

What does the cell membrane do?

The cell membrane is important to maintain HOMEOSTASIS! (which means balanced) You don't want too much or too little of molecules in your cells so the cell membrane is responsible for keeping this balance. Sometimes it lets more molecules in or kicks some out all it's trying do is make sure the cell is in balance (HOMEOSTASIS)

​

Why is the cell membrane important?

Molecules moving across the cell membrane is called cell transport. Sometimes it takes energy to move molecules across this is called active transport . sometimes it doesnt they just slip through the membrane this is called passive transport.

​

Cell transport

​Moves molecules from high concentrations to low concentrations this is called going with the gradient.
Because is is easy the dont require energy to do so.

Passive Transport

​Moves molecules from low concentrations to high concentrations this is called going against the gradient.
Because it is difficult require energy to do so.

Active Transport

​Passive Transport does not require energy to move molecules across the membrane, this is because molecules go with the concentration gradient (think go with the flow) , this is from high concentrations to low concentrations.
There are 3 types of passive transport
1. simple diffusion- molecules squeeze through the membrane
2. Facilitated diffusion- molecules use a protein tunnel to cross
3- osmosis- water passes through the membrane

Passive Transport

​Active Transport doesrequire energy to move molecules across the membrane, this is because molecules go against the concentration gradient (think going against the flow) , this is from low concentrations to high concentrations.
There are 3 types of active transport
1. endocytosis- cell membrane makes bubbles to bring molecules in
2. exocytosis- cell membrane makes bubbles to take molecules out
3- sodium potassium pump- protein powered by ATP moves molecules in and out

Active Transport

Cellular respiration occurs in the mitochondria, This is the process that makes ATP (energy source). It uses glucose and oxgen to produce ATP and in the process produces CO2 and water.

​

Cellular Respiration

Your muscles are FULL of mitochondria, this makes sense because it takes energy (ATP) for us to move. The more we move the more ATP we need. In order to create more ATP they need more reactants (ingredients) so more oxygen, how do we get more oxygen we breathe more.

​

Exercise

Categorize

Options (6)

osmosis

facilitated diffusion

simple diffusion

endocytosis

exocytosis

protein pump

Organize these types of transport into the right categories

Passive Transport

Active Transport

Dropdown

Cellular Respiration occurs in the ​

Select answer

, it uses ​

Select answer

to create ​

Select answer

Multiple Choice

The role of the cell membrane to maintain homeostasis is by

• controlling what goes in and out of the cell

• creating proteins

• catalyzing reactions

• making ATP energy