Biophysics Flashcards
Why can water form hydrogen bonds via cohesion and adhesion?
Because it is highly electronegative (dipolar)
What does the fact water forms H bonds mean for its properties
It has a high boiling point
How does water dissolve polar/charged groups?
Forming a hydration shell
Via charge interaction or hydrogen bonding = dissolved
Name some ionic compounds that get dissolved by water
Na+ , cl-
What are some examples of charged side groups getting dissolved
Carboxylate COO- (aspartate)
Phosphate
What are polar groups name some examples dissolved in water
Thiol SH
Serine OH
Alcohol rOH
What in a cell is called ‘amphiphatic’
The phospholipid bilayer
How are folding of proteins an example of hydrophobicity interaction
A polar side groups such as valine pack inside the protein
Charged are outside
How many moles in 12 g of C12
1 mole = molecular weight(g/mol)
How many atoms in a mole (Avogadro)
6.022 x 10^23
How would you work out moles from M and volume in Litres
M x volume in litres = moles
What is Brownian motion
Random movement of particles and collisions due to thermal energy
When would Brownian motion of particles stop?
At 0 kelvins (depends on thermal energy)
Why would large particles move slower in Brownian motion
Due to more collisions - the free path is reduced
What is needed for diffusion
Brownian motion through a concentration gradient (high to low)
What is steady state diffusion
When the concentrations of 2 places remain constant
What does flux mean in diffusion
Net movement of particles from 1 conc to another
Why do long distances take longer in diffusion
More collisions, it moves left and right due to mean free path being short
What produces turgor pressure
The semipermeable membrane acting as a barrier to charged ions
The bounce of = pressure
What causes osmotic pressure?
The semipermeable barrier to ions which bounce off causes osmotic pressure
The water would leave the cell (lysis)
What are exponents and how does it relate to biology
Another word for indices eg 10^2
2= exponent
Exponential growth eg in binary fission/PCR
What would 10^0 be?
1
How would you multiply 2 indices? Eg 10^5 x 10^ 3
5+3 = 10^8
How would you divide exponents eg 10^3 / 10^2
10^1
3-2
What would 1/100 represent as exponents
10^-2
1/10^2
How would you write 10^-1 in logarithms instead
Log10(0.1) = -1
Exponent = returned
How would you write 10^3 in log (=1000)
Log10 (1000) = 3
What is 0.001 as an exponent
10^-3. (1/10^3)
How would you add logs or divide logs eg of 2 solutions
Log 10 (H+A) = multiplication of logs
Log 10 (H-A) = divide logs
What would 5^6 be as a log form
Log5(15625) = 6
