Chapter 5 Flashcards
Membranes have selective permeability meaning that
only some substances can get across membrane
Phospholipids are amphipathic and so are its
proteins
Glycoprotein
- cell recognition
-protein embedded in cell membrane with carbohydrate side chain
Glycolipid
- cell recognition
- carbohydrate side chain attached directly to phospholipid bilayer
Fluid Mosaic Model
described phospholipid bilayer and its integrins
Channel proteins are
hydrophilic
Carrier Proteins
change shape to allow molecules through
Signal Transduction
signals within body pick up signaling molecule, molecules activate by changing shape
Intercellular Joining
cells get next to each other to ooze into each other
Polar molecules do not go through cell membranes easily, they need the help of
Integrins
Transport Proteins
allow the passage of hydrophilic substances across cell membrane
Diffusion
passive process - no energy
greater concentration to lesser concentration
Passive Transport
does not require energy
Osmosis
diffusion of water across a selectively permeable membrane
Tonicity
concentrations inside or outside of a cell causing it to lose or gain water
Osmoregulation
control of the solute concentration and water balance
- contractile vacuole
Facilitated Diffusion
Passive
protein is used
ion channels open and close in response to stimulus
Active Transport
moves substances across membrane against their concentration gradient; requires energy usually with ATP
Sodium Potassium Pump
Active
1 ATP pumps out 3 Na and moves in 3 K
example of active transport
Membrane Potential
voltage across membrane caused by differences in anions and cations
Electrochemical Gradient
2 combined forces; diffusion of ions across membrane
Electrogenic Pump
transport protein voltage
Bulk Transport requires
energy
Endocytosis
into cell
examples
- Phagocytosis, Pinocytosis, Receptor
Paracrine Signaling
signaling cells get close and secrete cytoplasm on each other
Endocrine/hormonal signaling
long distance signaling
Ligand Binding
- specific
- causes shape change in receptor, causing receptors to activate
- most receptors are plasma membrane proteins
Ligands
signal molecule
gated ion channels to that open when receptor changes shape
G Protein
- coupled receptors
- work with G protein, bond to GTP that are similar in structure
When a receptor is activated it continuously activates…
another receptor
like dominoes falling
Protein Kinases
transfer phosphates from ATP to protein - causing Phosphorylation
Dephosphorylation
phosphates are removed from proteins
phosphates deactivate signal transduction pathway and make protein kinases available for reuse
