Plasma Membrane Structure Flashcards
Why do cells have membranes?
Control entry and exit of certain substances
What does the plasma membrane contain?
- phospholipids
- channel proteins
- carrier proteins
- glycoproteins
- glycolipids
- extrinsic protein
- intrinsic protein
- cholesterol
What is the structure of a glycoprotein?
- protein
- carbohydrate chain
What is the structure of a glycolipid?
- phospholipids
- carbohydrate chain extends from phospholipids bilayer into watery environment outside cell
What is an intrinsic protein?
Protein that sits through the membrane
What is an extrinsic protein?
Protein that sits in the external membrane
What is the role of the channel protein?
Allows entry of water soluble molecules such as chloride ions and sodium ions
What is the role of the carrier protein?
way to transport bigger water soluble molecules across the membrane such as amino acids and glucose
What happens when carrier proteins bind with their specific solute molecule with complementary shape?
Other end opens up and lets the solute out
What are 2 examples of intrinsic proteins?
Carrier proteins and channel proteins
What is the role of the cholesterol?
- Makes membrane stronger and more rigid
- very hydrophobic to prevent water loss
What are the functions of glycoproteins?
- allow cells to recognise each other
- act as cell surface receptors
- helps cells attach to each other to form tissues
What is the role of the thick, hydrophobic portion of membrane?
- allows lipid soluble (non polar) substances and small molecules like water to pass through
- prevents most water soluble (polar) substances passing through
What is the role of phospholipids?
Makes membrane flexible and self sealing
What is the role of the glycolipid?
- acts as cell surface receptor for specific chemicals
- help maintain stability of membrane and help cells attach to one another to form tissues
