Unit 3

What requires ATP (cellular energy)?

Exocytosis, solute pumping, endocytosis, phagocytosis

What is driven by kinetic enegery of molecules?

simple diffusion, osmosis diffusion

What is driven by hydrostatic (fluid) pressure?

filtration

What follows a concentration gradient?

Simple diffusiom, osmosis diffusion

What proceeds against a concentration gradient and requires a carrier

solute pumping

What is a mean of secreting cell products?

exocytosis

What moves water through a semipermeable membrane>

osmosis diffusion

What transports amino acids, some sugars, and sodiums through the plasma membrane?

Solute pumping

What provides for cellular uptake of solid or large particles from the cell exterior>

endocytosis and phagocytosis

What moves small or lipid soluable solutes through the membrane?

simple diffusion

Cells consits of what 3 major parts

nucleus, cytoplasm, plasma membrane

What are the parts of a double layer of phopholipid molecules?

polar heads (hydrophilic) andfatty acid tails (hydrophobic)

Cell membranes contain what different types of proteins

globs, rods, fibers

What is the functionn of carbohydrates in the cell membrane?

cell recognition and adhesion

WHat is the function of cholesterol in the cell membrane?

stabilizes the membrane

Whqt are the 4 types of passive mechanisms?

diffusion, facilitated dffusion, osmosis, filtration

Simple diffusion

high conc. → low conc. until equilibrium

ex: sugar or food dye

Facilitated diffusion

high conc. → low conc. bur selectively permeable membrane involved

= use of a helper protein

Osmosis

solvent moleules move across a selectively permeable membrane in water

what are the 3 types of osmosis

isotonic- same pessure outside and inside

hypertonic- solution has higher osmotic pressure than bodu fluids (cells shrink)

hypotonic- solution has lower osmotic pressure (cells swell)

filtration diffusion

forces molecules through membranes by hydrostatic pressure- used to seperate solids from water

ex: coffee

what is the diff between diffusion and osmos

osmos uses a slective membrane

active mechanisms moves particles from a region of conc to conc.

low to high conc

Examples of pumps

sugars, amino acids, sodium, potassium, calcium

What are two other processes that use cellular energy without crossing the cell membrane

edocyctosis and exocytosis

exocytosis

vesicle fuses with membrane to expell substances from cell

ex: secretion of certain hormones