Cell membrane Flashcards
True or false, the cell membrane is a semi-permeable membrane
True
What is the function of the cell membrane?
It acts as the boundary of all cells, regulating the flow of substances in and out
Why is the cell membrane considered semi-permeable?
It allows only small or non-polar substances to pass freely while restricitng others
What are the four main components of the cell membrane
Phospolipid bilayer, cholesterol, protein carriers/channels and glycoproteins/glycolipids
What is the function of protein carriers and channels
Allows larger non polar molecules to pass through the membrane
What are the two types of transport across the cell membrane
Passive transport (no energy required) and active transport (energy required)
What is diffusion
The net movement of a substance down its concentration gradient. The movement of molecules from an area of high concentration to an area of low concentration
When is faccilitated diffusion used
When substances cannot pass between the phospholipid bilayer e.g polar or ions, na^+, glucose
Where does facilitated diffusion occur
through transport proteins including channel proteins and carrier proteins
What is the definition of facilitated diffusion
The passive movement of molecules along a concentration gradient through the use of a channel or carrier protein
what is osmosis
the net diffusion of water down its own concetration gradient. Water moves from an area of low solute concentration across a semi permeable membrane to ana rea if high solute concentration
What is active transport
The net movement of a dissolved substance into or out of a cell against its concentration gradient. It uses carrier proteins
True or false, active transport does not need energy
false
What is endocytosis
Bulk transport into the cell e.g big proteins
True or false, Endo and exocytosis require energy in the form of atp
True
What does phago mean
eat
What does pino mean
Drink
What are the two types of endocytosis
Phagocytosis (solids) and pinocytosis (solutions)
What is exocytosis
Bulk transport of substances out of the cell
What is the purpose of exocytosis
cellular wastes can be excreted/secreted
