W4L1 - Cell Integrity Flashcards
What is the fluid mosaic model
Explains how molecules are specifically arranged in the membrane
What is cell sidedness
integral membrane proteins are stuck in specific ways as it moves from inside the cell to outside the cell
What are the two sides of proteins in cell sidedness
Inside rough ER > interior of vesicle > transported to the extracellular space| Outside rough ER > exterior of vesicle > still faces the cytoplasmic side of the cell
Explain cell sidedness as it moves from the rough ER to the outside of cell
The inside (lumen) of the rough ER becomes the inside of vesicles and then ends up as the outside surface of the plasma membrane
What is the 3 main composition of the membrane
lipids, proteins, CHO
What kind of molecules can pass through the cell membrane
Small, nonpolar (hydrophobic) molecules can pass through easily because they dissolve in the membrane’s hydrophobic core — like dissolves like.
What happens when a molecule is too ionised, large and polar to cross the cell membrane
need specific transport
What is tonicity
How a cell shrinks/expands based on the concentration of solutes
explain tonicity in animal cells
Homeostatic balance of ions in and outside the cell (isotonic environment) as animal cells do not have cell walls
Explain tonicity in plant cells
require a hypotonic environment → where there are less solutes and higher levels of H2O
What does fluidity mean
Ability of lipids and proteins to be able to move around the cell membrane side to side
Explain how red blood cells are important for maintenance of cell integrity
RBC > deliver O2 > body tissues > O2 in lungs > release via squeezing through capillaries > sustain substantial mechanical force
What is diffusion
small molecules e.g O2, CO2 diffusing through a membrane > difference in conc > net movement until equilibrium is reached
What occurs in a hypotonic solution in animal/plant cells
Animal cell > Too much water goes in bursts/lysed, Plant Cell > cytoplasm swells > plasma membrane gets slightly pushed against the cell wall
Isotonic/ flaccid solutions in animal and plant cells
Homeostatic balance of water
Hypertonic solution in plant and animal cells
Too much water leaving the cell > Animal cells becomes shrivelled > plant cells > cytoplasm pulls away from the cell wall > wilts
