Quiz 2 Flashcards
(39 cards)
What is the protein solubility at the isoelectric point?
lowest possible, bcs neutral charge
What does thermodynamics allow us to tell about bioenergetics? What is important to consider when doing calculations?
- reversible?
- favoured
final and initial values used for ∆G/H/S no focus on the pathways
∆S of the universe is assumed to be a certain level of energy, what is it?
∆S universe > 0
Knowing that ∆S(universe) > 0, we can presume that the ∆G is?
∆G < 0
Processes that decrease the amount of energy in a system do what to the ∆G?
∆G < 0, favoured
Processes that increase the amount of disorder in a system do what to the ∆G?
∆G < 0, favoured
In biochemistry entropy can and does decrease within favorable reactions, how does the system make up for it?
entropy can decrease as long as the enthalpy is large enough to account for it
- energy expelled is greater than the energy lost for organization
What is the equation that connects free energy, equilibrium, and concentration?
∆G = ∆Gº + RTlnQ
∆Gº is the standard value
R is gas constant
T is temp in Kelvin
Q is products/reactants
Homeostasis is not ______-
equilibrium
The relationship between K and Q indicates the energy and reaction direction
Q < K
Q = K
Q > K
Q < K = -∆G = forward reactions (products)
Q = K = 0 = equilibrium
Q > K = +∆G = reverse reaction (reactants)
Unfavourable reactions exit in biochemistry but are driven in the forward direction by 2 things
Q/K > 1 (consume as fast as produce, or have high concentration of reactants
coupling favourable reactions
What is the full name of RNA
B-D-ribose (B-beta)
What is the full name of DNA
B-D-2-deoxyribose (B-beta)
The sugar that makes of the structure of primary nucleic acids is made of what and what does it look like?
5-carbons
Beta isomer at anomeric C
Difference between nucleosides and nucleotides
nucleosides = sugar + base
nucleotides = sugar + base + phosphate
On a nucleic acid drawing indicate the glycosidic bond and phosphodiester bonds
find ss
What are the two conformations for nucleic acids? Draw + indicate which is used by DNA and RNA, and indicate why.
C2’ endo = DNA, 7.0A between phosphates
C3’ endo = RNA, 5.9A between phosphates
Steric constraints hinder rotation around the glycosidic bond, this allows for two conformations, which is more favourable?
- syn
- anti = more favourable for double helix interstrand bonding
Draw out the tautomeric conformations and which is more favourable
keto* <=> enol
amine* <=> imine
Draw a Fisher projection, what are the steps
- orient acid up (into the page
- orient side chain down (also into the page)
- determine which side the amino group is on (Left = L, right = D)
How are polynucleotides formed?
coupled reactions
- break high energy phosphate bonds
Go over the 20 amino acids
- non-polar, polar, acidic, basic
- name, 3 letter code, 1 letter code
- pKa of ionizable side chains
find ss
Two amino acids have beta branches with stereochem. What are they? Draw out the line drawing and Fisher projection
isoleucine = Ile = I
(L-L)
threonine = Thr = T
(L-D)
Which amino acid is the most hydrophobic?
phenylalanine = Phe = F
