Question | Answer |
The cell membrane protects what? | The cell |
Certain materials need to enter the cell. Some important materials a cell needs come through the membrane. Some are: | water, food, oxygen |
The mebrane helps cells | get rid of waste and collect important materials(move in and out) |
The membrane can be like a | gatekeeper-lets certain things in and out. |
Between the lipids there may be | protein and carbohydrate molecules attached. |
Carbs and proteins help by: | helping materials move through the membrane. |
A membrane is selectively permeable. What does this mean? | certain substances are allowed to enter the cell while others cannot enter. |
The structure of a cell membrane reflects its: | function. |
Fats do not mix with what? | water |
the fat molecules on the membrane loves or does not love water? | loves water. |
There are two types of transport: | Passive and active |
Through passive transport what happens | materials like water, gases, or dissolved solutions, cross the membrane without using energy. |
What are the 2 types of passive transport? | diffusion and osmosis. |
What is diffusion? | The movement of materials from areas of high concentration to low concentration. |
What types of molecules travel through diffusion? | Small and gas molecules. |
Diffusion occurs until: | Both concentrations are equal. |
How do molecules move: | molecules gather in an area, collide, and then push away. |
Molecules that are too big to get across use: | facilitated diffusion. |
What is facilitated diffusion: | The process in which proteins create a channel for the other molecules to pass through. |
The molecules need | "assistance" because they are too fat. |
What is an example of a molecule that uses facilitated diffusion? | Glucose. |
It is a carrier protein:True or False | True |
What is osmosis: | The diffusion of water molecules across a cell membrane(selectively permeable) |
Osmosis is a form of: | Passive transport |
Does osmosis use energy | No. |
Under certain conditions, osmosis can cause water to move more quickly out than in. This results in: | the cytoplasm shrinking and the organelles in it pulling away from the membrane. If conditions don't change, the cells can die. |
Sometimes when they have too much water they use what: | a pump-contractile vacuole. |
An example is a | paramecium-constantly having water come in. |
Is this passive transport | no |
The paramecium's solution using the pump: | it pumps the water out using energy. |
When substances move in and out of the membrane using energy it is | active transport. |
In Active transport molecules move from areas of | lower concentration to higher concentration.-involves energy. |
They move the opposite way due to | diffusion |
What helps the substances move? | proteins |
Substances that are "picked up" and carried are | Calcium, Potassium, and sodium. |
Active transport includes: | Ion pumps, endocytosis, and exocytosis. |
An ion pump is: | A pump that transports proteins and molecules from areas of lower concentration to higher concentration using energy. |
When materials are too large too move through pumps.. they use | endo/exocytosis. |
The process of endocytosis is: | a particle gets engulfed by the cell. The membrane then fuses and creates a vacuole(vessel or bubble) that is taken across the membrane into the cell where it spreads. |
Does endocytosis use energy: | No |
What are 2 things engulfed? | Bacteria and food |
The opposite process is: | exocytosis |
The cells use energy to; | get big molecules out of the cell. |
Describe the procedure of exocytosis: | a vacuole fuses with the membrane and the membrane opens and spills out the contents. The membrane then fuses. |
Does exocytosis require energy: | yes. |
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