1.2. Transport across membranes Flashcards
Name the 2 molecules that make up the cell membrane.
Phospholipids and proteins
What do we call a process that does not require energy?
Passive
What do we call a process that does require energy?
Active
What is the definition of diffusion?
The movement of molecules from a higher concentration to a lower concentration down the concentration gradient
What is a concentration gradient?
The DIFFERENCE in concentration between two areas.
A membrane allows smaller molecules through quicker than larger molecules. How do we describe this property of the membrane?
Selectively permeable
What do we call the movement of water molecules form a HWC to a LWC through a selectively permeable membrane?
Osmosis
What happens to an animal cell placed in pure water?
Bursts
What happens to a plant cell placed in pure water?
Turgid
What happens to an animal cell placed in high sugar solution?
Shrinks
What happens to a plant cell placed in high sugar solution?
Plasmolysed
Why does a plant cell not burst or shrink?
Strong cell wall made of cellulose
What do we call the movement of molecules from a low concentration to a high concentration against the concentration gradient?
Active transport
State 2 things needed for active transport to take place?
- Energy
- Protein carriers
- Glucose
- Oxygen
I say osmosis you say…
water!
