Lecture 3 Part 2 Flashcards
(41 cards)
Fluid outside cells
Interstitial fluid
Interstitial fluid is made of:
Amino acids Sugars Fatty acids Vitamins Hormones Salts Wastes
Plasma membrane only allows some substances to enter cell
Selective Permeability
Two types of transport:
Passive
Actives
No energy (ATP) needed
Passive transport
Molecules move from high to low concentration
Down concentration gradient
Two types of passive transport:
Diffusion
Filtration
Nonpolar and lipid-soluble substances diffuse directly through lipid bilayer
Simple diffusion
Example of substances that undergo simple diffusion
O2
CO2
Fat-soluble vitamins
Transport proteins (carrier or channel proteins) assist molecules across membrane
Facilitated diffusion
Example of transport proteins:
Glucose
Amino acids
H2O
Ions
Water-filled channels
Channel proteins
Example of channel proteins:
Ions
Binds molecule, changes shape, ferries it across membrane
Carrier proteins
Example of carrier proteins:
Glucose transporter
Diffusion of H2O
Osmosis
Channel proteins for H2O passage
Aquaporins
Ability of solution to change shape or tone of cells by changing water volume
Tonicity
Types of tonicity:
Isotonic
Hypertonic
Hypotonic
Equal concentration solutes
Isotonic
Higher concentration of solutes
Hypertonic
Lower concentration of solutes
Hypotonic
Energy (ATP) is needed
Active transport
Molecules move from low to high concentration
Against concentration gradient