Biophysics

Question 1

Why can water form hydrogen bonds via cohesion and adhesion?

Answer 1

Because it is highly electronegative (dipolar)

Question 2

What does the fact water forms H bonds mean for its properties

Answer 2

It has a high boiling point

Question 3

How does water dissolve polar/charged groups?

Answer 3

Forming a hydration shell

Via charge interaction or hydrogen bonding = dissolved

Question 4

Name some ionic compounds that get dissolved by water

Answer 4

Na+ , cl-

Question 5

What are some examples of charged side groups getting dissolved

Answer 5

Carboxylate COO- (aspartate)

Phosphate

Question 6

What are polar groups name some examples dissolved in water

Answer 6

Thiol SH

Serine OH

Alcohol rOH

Question 7

What in a cell is called ‘amphiphatic’

Answer 7

The phospholipid bilayer

Question 8

How are folding of proteins an example of hydrophobicity interaction

Answer 8

A polar side groups such as valine pack inside the protein

Charged are outside

Question 9

How many moles in 12 g of C12

Answer 9

1 mole = molecular weight(g/mol)

Question 10

How many atoms in a mole (Avogadro)

Answer 10

6.022 x 10^23

Question 11

How would you work out moles from M and volume in Litres

Answer 11

M x volume in litres = moles

Question 12

What is Brownian motion

Answer 12

Random movement of particles and collisions due to thermal energy

Question 13

When would Brownian motion of particles stop?

Answer 13

At 0 kelvins (depends on thermal energy)

Question 14

Why would large particles move slower in Brownian motion

Answer 14

Due to more collisions - the free path is reduced

Question 15

What is needed for diffusion

Answer 15

Brownian motion through a concentration gradient (high to low)

Question 16

What is steady state diffusion

Answer 16

When the concentrations of 2 places remain constant

Question 17

What does flux mean in diffusion

Answer 17

Net movement of particles from 1 conc to another

Question 18

Why do long distances take longer in diffusion

Answer 18

More collisions, it moves left and right due to mean free path being short

Question 19

What produces turgor pressure

Answer 19

The semipermeable membrane acting as a barrier to charged ions

The bounce of = pressure

Question 20

What causes osmotic pressure?

Answer 20

The semipermeable barrier to ions which bounce off causes osmotic pressure

The water would leave the cell (lysis)

Question 21

What are exponents and how does it relate to biology

Answer 21

Another word for indices eg 10^2

2= exponent

Exponential growth eg in binary fission/PCR

Question 22

What would 10^0 be?

Answer 22

1

Question 23

How would you multiply 2 indices? Eg 10^5 x 10^ 3

Answer 23

5+3 = 10^8

Question 24

How would you divide exponents eg 10^3 / 10^2

Answer 24

10^1

3-2

Question 25

What would 1/100 represent as exponents

Answer 25

10^-2

1/10^2

Question 26

How would you write 10^-1 in logarithms instead

Answer 26

Log10(0.1) = -1

Exponent = returned

Question 27

How would you write 10^3 in log (=1000)

Answer 27

Log10 (1000) = 3

Question 28

What is 0.001 as an exponent

Answer 28

10^-3. (1/10^3)

Question 29

How would you add logs or divide logs eg of 2 solutions

Answer 29

Log 10 (H+A) = multiplication of logs

Log 10 (H-A) = divide logs

Question 30

What would 5^6 be as a log form

Answer 30

Log5(15625) = 6