Week 3 Cell Membrane Flashcards
Give 2 other names for the cell membrane?
Plasmalemma or plasma membrane.
List the 4 functions of the cell membrane?
Physical isolation, regulates exchange with environment, monitors the environment, & structural support.
What are the 3 main components of the cell membrane?
Lipids, proteins & carbohydrates.
What does the phospholipid bilayer consist of?
A double layer of phospholipid molecules: Hydrophilic phosphate heads & hydrophobic fatty-acid tails.
List the 6 functions of membrane proteins?
Anchoring proteins, recognition proteins, enzymes, receptor proteins, carrier proteins & channels.
What are the functions of membrane carbohydrates?
Lubrication & protection, anchoring & locomotion, specificity in binding & recognition.
What are the 3 categories of cell membrane transport?
Diffusion (passive), carrier-mediated (passive or active), & vesicular (active).
What factors affect diffusion rates?
Distance, molecue size, temperature, gradient size, & electrical forces.
What are the 2 types of diffusion?
Simple & channel-mediated.
What factors affect channel-mediated diffusion?
Size, charge & interaction with the channel.
What is osmosis?
The diffusion of water across the cell membrane.
What is osmotic pressure?
The force of a concentration gradient of water. It equals the force (hydrostatic pressure) needed to block the process of osmosis.
What is another name for vesicular transport?
Bulk transport.
What are the 3 types of carrier-mediated transport?
Facilitated diffusion (passive), Primary active transport & Secondary active transport.
What are the characteristcs of carrier-mediated transport?
Specificity, saturation limits & regulation.
How does facilitaed diffusion work?
Carrier proteins transport molecules too large to fit through cannel protiens (e.g. glucose). The molecule binds to a receptor site on the carrier protein, the protein changes shape & the molecule can pass through. The recptor is specific to certain molecules.
Primary active transport moves substrates against a concentration gradient & therefore requires energy in the form of ATP. True or false?
True e.g. sodium/potassium pump
What is countertransport?
the active transport of one substrate moving into the cell while another moves out.
What is another name for countertransport?
Antiporters.
What is another name for cotransport?
Symporters.
What is cotransport?
A primary active transport of 2 substances in the same direction at the same time.
What are the 2 types of vesicular transport?
Endocytosis & exocytosis.
What are the 3 types of endocytosis?
Receptor-mediated, pinocytosis & phagocytosis.
What is pinocytosis?
“Cell drinking”. The taking in of water by a cell.
What is the difference between integral & peripheral protiens?
Integral sit within the cell memebrane & peripheral are on the inner or outer surface of the cell membrane.
