3.1

diffusion

substance in greater concentration on one side of a semipermeable membrane will move down concentration if it can

diffusion

O2 diffuses into cell because generally higher concentration is outside cell

diffusion

CO2 diffuses out of cell because generally more concentration is inside cell

crossing lipid bilayer

large polar or ionic molecules cannot easily cross bilayer

large polar or ionic molecules cannot easily cross bilayer

very small polar molecule (H2O) can diffuse due to size

crossing lipid bilayer

charge atoms or molecules of any cannot cross bilayer

charge atoms or molecules of any cannot cross bilayer

repelled by hydrophobic tails

crossing lipid bilayer

most solutes dissolved in H2O cannot pass freely through lipid bilayer

most solutes dissolved in H2O cannot pass freely through lipid bilayer

movement restricted to protein channels + specialized transport mechanisms

facilitated diffusion

process used for those substances that cannot cross due to size, charge, +/or polarity

facilitated diffusion

two “type”

1 type of facilitated diffusion

specialized carrier proteins transfer molecules into cell to facility its inward diffusion

2 type of facilitated diffusion

membrane proteins form channels or gateways so substances can move down their concentration gradient

osmosis

diffusion of H2O through a semipermeable membrane

isotonic

2 solutions have same concentration of solutes

isotonic

cells must maintain equal concentration of H2O inside + outside to function

hypertonic

solution with higher concentration of solutes

hypertonic

H2O tends to diffuse into

hypertonic

cells will shrivel as H2O leaves cell

hypotonic

solution with lower concentration of solutes

hypotonic

H2O tends to diffuse out

hypotonic

cells will swell + risk bursting

filtration

uses a hydrostatic pressure gradient to push fluid + solutes in from area of higher pressure to area of lower pressure

filtration

movement of plasma + substances out of capillaries + into surrounding tissue

filtration

mechanism that kidneys use to remove water from bloodstream

active transport

ATP needed to move substance across a membrane

active transport

often against its concentration gradient

active transport

often with help of protein “pumps”

active transport

through endocytosis (process of cell ingesting material)

sodium-potassium pump

maintains high concentration of sodium ion outside of cell

sodium-potassium pump

maintains electrical gradient

sodium-potassium pump

concentration of NA+ outside and K+ inside cell

sodium-potassium pump

difference in electrical charge across a space

cells need sodium ion

opens passive sodium channel

passive sodium channel

concentration gradient of sodium drives sodium into cell

endocytosis

process of cell ingesting material

endocytosis

material ingested is enveloped in a portion of cell membrane

endocytosis

material ingested becomes independent intracellular vesicle

phagocytes

large particles

pinocytes

fluid with dissolved substances

receptor-mediated endocytosis

portion of cell membrane with receptors for specific substance (ligand)

receptor-mediated endocytosis

cell membrane envelopes receptor-ligand complex

exocytosis

exporting material using vesicular transport

exocytosis

substances produce in cell package for transport

exocytosis

membrane-bound vesicles fuse with cell membrane

exocytosis

vesicle releases it contention into interstitial fluid

example of exocytosis

secretion of digestive enzymes

example of exocytosis

release of hormones

example of exocytosis

immune cells produce histamine