BIO!!

the concentration gradient: ATP

The force driving simple diffusion is _____, while the energy source for active transport is _____

Only certain molecules can cross a cell membrane.

Which of the following most accurately describes selective permeability?

lysocomes

a bacterium engulfed by a white blood cell through phagocytosis will be digested by cells contained in

diffusion

a passive process in which molecules move from a region of higher concentration to a region of lower concentration

active vs passive transport

active needs energy; passive does not need energy (diffusion)

aquaproins

allows water molecules to move faster across the cell membrane

selective permeability

characteristic of the plasma membrane which allows certain materials in or out of the cell

Mitochondria

cyanide binds with a least one molecule in ATP, if a cell membrane contains cyanide, most of it will be found here

Osmosis

diffusion of water; how polar H2O gets across the membrane

smaller nonpolar molecules

what can most easily move across the membrane

it maintains fluidity by preventing tight packing

what happens when a membrane is cold

cholesterol restrains movement of phospholipids

what happens when a membrane is hot

Phagocytosis

white blood cells engulf bacteria using this