Cell Membrane and Transport Flashcards
What does semi-permeable mean?
Allowing certain substances to pass through it but not others, especially allowing the passage of a solvent but not of certain solutes.
What is the fluid mosaic model?
It explains how scientists describe what the cell membrane looks like and how it functions
What are phospholipids composed of?
A hydrophobic fatty acid tail, and a hydrophilic phosphate head
What is the purpose of cholesterol in the cell membrane?
Cholesterol helps maintain the cell membranes stability at varying temperatures.
What is the cell membrane?
A flexible phospholipid bilayer that controls the entry and exit of substances and encloses the cell.
What are the two main cell membrane protein?
Channel Proteins & Carrier Proteins
What is the function of channel proteins?
Catalyse the movement of specific ions and some simple molecules.
What are aquaporins?
Channel proteins that facilitate the movement of water.
How do carrier proteins work?
Carrier proteins change their shape to bind to specific molecules.
What is the function of carrier proteins?
Use ATP to transport specific molecules or ions against their concentration gradient.
What are two other membrane proteins?
-Adhesion proteins
-Receptor proteins
What are three types of transport across the cell membrane?
- Osmosis
- Passive Transport
-Active Trasport
What is Osmosis?
The diffusion of water across the cell membranes.
Water will move to the side that has a greater solute concentration.
What are the two types of passive transport?
- Diffusion
- Facilitated Diffusion
What is diffusion?
Diffusion is the movement of particles from a high to low concentration
