Key points Transport across the cell membrane Flashcards
what is the cell membrane composed of?
The cell membrane is composed of phospholid and protein
What is selectively permeable
The cell membrane
Remember a difference in concentration of a substance is a concentration gradient
Remember a difference in concentration of a substance is a concentration gradient
What is passive transport
Passive transport is when a substance does not require extra energy to move the molecules down the concentration gradient = high to low :)
What are 2 examples of a passive transport process
Diffusion and osmosis
What is diffusion
The process of going down a concentation gradient
high to low :)
Things that enter most cells by diffusion
oxygen glucose and amino acids
substance that leave cells by diffusion are
carbon dioxide
what is osmosis
It is the movement of ONLY WATER MOLECULES from a high concentrationt to a low concentration through the selectively permeable membrane.
Turgid
Turgid is the term used to describe a cell he where the vacuole has shrunk due to water gain the cytoplasm then presses against the cell wall
plasmolaysed
This is where the vacuole has shrunk due to water loss the causes the cell membrane against the cell wall.
Active Transport
This is when the movement of molecules from a low concentration to a high concentration against the concentration gradient.
What does active transport need
Active transport needs addidntional energy from the ATP to allow it to go up the concentration gradient.
