Rafferty 1 Flashcards
define and give the equation for pI (where there are 2pK values)
pI is the zwitterionic form of an amino acid. (pK1+pK2)/2=pKI
give the henderson-hasselbalch equation
pH=pKa+log([A-]/[HA])
enzymes enhance the rate to go to the e_______ point
equivalence
do enzymes increase or decrease the energy barrier for the forward and backward reactions?
decrease
what is an apoenzyme and a holoenzyme? what is the equation that relate these two forms of enzyme?
apoenzyme = enzyme without cofactor
holoenzyme = enzyme with cofactor that is catalytically active
apoenzyme+cofactor=holoenzyme
give the 2 types of cofactor
metals and coenzymes
define a coenzyme
subdivision of a cofactor - small organic molecule
give the 2 types of coenzyme and define them
cosubstrate - loosely bound coenzyme (binds and is released from enzyme like substrate/product)
prosthetic group - tightly bound coenzyme
define a cofactor
additional molecule that increases the number of available functional groups to aid catalysis
name and describe the 6 types of enzyme
- oxidoreductases: redox reactions eg by nad+
- transferases: functional group transfer (1 e-philic group from 1 nucleophile to another)
- hydrolases: specific transfer reaction via H2O addition
- lyases: addition/removal of groups to make double bonds
- isomerases: conversion between isomeric forms
- ligases: joining two molecules, requires chem energy source
what type of bond stabilizes IgG?
disulphide bridge
name the 6 domains in IgG
VL/VH/CL1/CH1/CH2/CH3
where to ab’s bind on IgG?
hypervariable beta-sheet loops on the N-terminal variable region
name and quantify the number of regions in IgG, how can these regions be separated?
2xFab 1xFc, split by papain
what are the 3 main functions of a membrane?
- separate cells from env
- internal membranes for boundaries of organelles
- env for critical biological processes
name the types of molecule that are membrane (im)permeable
permeable: gases/small uncharged polar (can be semi-permeable)
impermeable: large uncharged polar molecules/ions/polar molecules
name 3 main types of lipid
phospholipids, isoprenoids and glycolipids
which molecule can form a micelle?
fatty acids
what does increasing the alcohol content of a phospholipid membrane do?
increases its curvature
what is the effect of increasing double bond content in a fatty acid?
increases membrane fluidity
what is the effect of asymmetric lipid distribution in a membrane?
changes in membrane curvature
what is the effect of cholesterol in a membrane?
decreases fluidity - cholesterol has planar steroid ring which gives it mechanical stability
increased order - this is due to its planar, inflexible tail, which makes the phospholipids elongate - therefore increased membrane thickness
what is the effect of increasing order in a phospholipid membrane?
membrane increases in thickness - this is because the f/a chains straighten
what is the effect of increasing temperature in membrane containing cholesterol?
gel consistency becomes more fluid which decreases phospholipid order and therefore decreases in thickness
