Topic 2: Cell Phys.1 Flashcards
(27 cards)
What are 3 important structures of the cell membrane?
Phospholipid bilayer
Membrane proteins
Membrane carbohydrates
What are the 5 types of membrane proteins?
Transport proteins
Receptor proteins
Enzymes
Joining proteins
Identifying proteins
These allow for carrier-mediated facilitated diffusion or active transport by binding to a solute and carrying it across the cell membrane
Carrier proteins (transport protein)
Is the phospholipid bilayer a barrier to water soluble OR lipid soluble substances/molecules?
The membrane is a barrier to water soluble substances
What are the 2 types of CHANNEL PROTEINS (transport proteins)?
GATED: can open or close
NON-GATED: always open
What are identifying proteins?
Major Histocompatibility Complex (MHC) proteins that are found on the surface of all cells (except RBC) which identify the cell as “self”
What is a solute?
The substance that is dissolved
What causes passive transport (no ATP needed)?
Movement from high concentration to low
The greater the difference in concentration = the more molecules want to move
What are the types of passive transport?
Simple diffusion
Channel-mediated facilitated diffusion
Carrier-mediated facilitated diffusion
Osmosis (solvent movement)
Name the type of passive transport:
Solute diffuses directly through cell membrane
Simple diffusion
Name the type of passive transport:
Ions diffuse through membrane via protein channels, moving freely through the channel
Channel-mediated facilitated diffusion
The pressure required to prevent the movement of water across a semipermeable membrane with osmosis
Osmotic pressure
High OP (osmotic pressure) = ?
High solute, low H2O
What determines the response of a cell immersed in a solution?
TONICITY
(hypotonic, hypertonic, isotonic)
Hypertonic solution or hypotonic?
ECF has higher OP (lower concentration of H2O)
HYPERtonic
Cell shrinks
If the body loses H2O, the concentration of blood increases. How does osmosis respond to this?
OP in the blood increases. The fluid moves from tissues into blood.
Response includes thirst and decrease in renal H2O loss
If a cell is surrounded by pure water, does the water have a HIGHER or LOWER osmotic pressure?
Low osmotic pressure (less solute than cell)
What type of solution can result in lysis (cell bursting)?
Hypotonic
What kind of solution has equal osmotic pressures?
Isotonic solution
The cell neither shrinks nor swells
Name the type of passive transport:
Large, charged, or water soluble molecules diffuse across membrane unsung a specific carrier protein which binds to it and transports into cell
Carrier-mediated facilitated diffusion
Water moves from areas of ____ osmotic pressure to areas of ____ osmotic pressure.
low, high
What type of protein binds to specific extracellular molecules like hormones and neurotransmitters?
(eg. glucose uptake)
Receptor proteins
These control chemical reactions on the outer and inner surfaces of cells
Enzymes
What moves substances against the concentration gradient?
Active transport
(always protein carrier-mediated)
