gen bio 2 exam 2 Flashcards
(123 cards)
Channel Proteins
Pore allowing for diffusion with aqueous interior
Has both open and closed states
Still need/follow the concentration gradient
Gating
Is the channel protein open/closed
Selectivity
What is let through the channel protein
Ligand Gated
A ligand is what opens the channel protein
Voltage gated
Opens the channel protein by votage differences, usually -70 mV inside cell, 30 outisde
Mechanically gated
Channel proteins open when they are stretched
Aquaporins
Channel proteins for water
Carrier Proteins
Bind a molecule, and bring it to the other side of a membrane
Random switches between its 3 states
Passive
Need concentration gradient
Transport Maximum
Carrier proteins are not infinite, and can not move infinite molecules
Pump
Active
Integral membrane protein
No concentration gradient is required
Sodium Potassium Pump
3 Sodium out (15 mM inside, 150 mM out)
2 Potassium in (140 mM in, 5 mM out)
1 ATP uses
Exocytosis
Stuff in a vesicle is sent to the cell wall where the membranes connect, and lumen contents deposited into extracellular fluid
Endocytosis
Phagocytosis
Pinocytosis
Receptor mediated endocytosis
Phagocytosis
“Cell Eating”, cell evaginates around an item, and cell membrane extends out towards around it to take it in as a vesicle
Pinocytosis
“Cell Drinking”, exocytosis but just extracellular fluid no item
Receptor mediated endocytosis
LDL connect to LDLRs, and when enough of them are cluster this triggers coating proteins attached to intracellular parts of LDLRs to cause evagination of the cell membrane
Digestion of vesicles
Lysosomes merge with the vesicles, and causes the LDLs to be removed from the LDLRs and then the cholesterol is broken down
Energy
Physics - capacity to do work
Biochem - capacity to cause change
Potential Energy vs Kinetic Energy
middle school science moment
1st + 2nd law of thermodynamics
1: Energy can not be created/destroyed, only change forms
2: Energy becomes more unstable/unusable as it changes forms
Entropy
increases over time, can be thought of as disorder/unusable energy in a system
H = G + TS
Total energy = Usable Energy + (Time*Unusable Energy/Entropy)
delta G
dG = G-products - G-reactants
if dG > 0, energy absorbed
if dG < 0, energy released
Exergonic vs endergonic
Exer = release, ender = absorb