Quiz 2 Flashcards
What does K stand for and what is it?
equilibrium constant
- strength of non-covenant interactions between molecules
Are covalent or non-covalent reversible?
non-covalent
What kind of bond is sharing of electrons?
covalent
What kind of bond has extensive orbital overlap?
covalent
What is an example of a covalent bond in immunology?
C3b binding to NH on pathogen surface
What are 4 examples of non-covlalent interactions?
- hydrogen bonds
- salt bridges (ionic)
- van der Waal
- hydrophobic interactions
What kind of NC interaction is two electronegative atoms competing for the same hydrogen?
hydrogen bond
What amino acids are involved in hydrogen bonds?
polar amino acids
What NC interaction is a bond between a positive and negative molecule?
ionic bonds (salt bridges)
What amino acids are involved in ionic (salt bridges)?
charged amino acids
What NC interaction is when one hydrophobic molecule is attracted to another hydrophobic molecule?
hydrophobic interactions
What amino acids are involved in hydrophobic interactions?
hydrophobic amino acids
What NC interaction is packing of atoms together?
van der Waal
What is the Ka equation?
R + L —> RL
What is the Kd equation?
RL —> R + L
What is Kd?
the disassociation constant
What is the Ka?
the association constant
What is the unit of measurement for Kd and Ka?
Kd = M
Ka = M-1
Large Ka = more or less RL?
more
small Kd = more or less RL?
more
Ka and Kd are ______ or each other
inverses
Kd = 1/??
Kd = 1/Ka
____ is a constant
Ka
ever RL complex has its own specific _____ and _____ based on NC interactions
Kd and Ka
What is f?
fraction of RL complexes at a given [L]
f is on the ___ axis
[L] is on the _____ axis
y
x
What does the f equation tell us?
how much RL is present at a specific [L]
What do binding curves show?
the amount of RL formed art any [L]
How do you find the Kd on a binding curve?
draw a line form 50% over and down and the number on the X axis is the Kd
The relationship between ___ and RL formation are the same for all interactions
Kd
If Ka is a constant why does the binding increase with concentration?
increasing [L], increases the probability of an interaction between R and L
How can you tell if a ligand has a stronger affinity than another?
The lower the Kd the more RL formed at the same [L]
Is affinity or avidity stronger?
avidity
What is apparent Kd?
actual Kd is different than the experimental Kd (avidity)
What 2 things does avidity binding require?
- R or L be attached to a surface
- requires the other component to have multiple binding sites
Does avidity or affinity have a smaller Kd?
avidity
What is responsible for the differences in affinities of different complexes?
the NC interactions
In specificity, ___________ interactions can cause steric repulsion preventing binding
van der waal
How do antibodies neutralize microbes involving specificity?
Antibodies disrupt these non-covalent contacts
- antibody has a smaller Kd than the microbe so it will have a higher affinity to bind to the site where the microbe wants to bind
