Biophysics

Question 1

ampiphathic molecules

Answer 1

polar and non polar end

Question 2

brownian motion

Answer 2

molecules in a sol. move due to thermal energy

mols move randomly due to collisions with each other

Question 3

turgor pressure

Answer 3

diffusion in presence of barriers

Question 4

osmolarity

Answer 4

number of moles per unit volume

Question 5

thermodynamics of a reaction tell us…

Answer 5

whether a chemical reaction can be used as energy currency

whether the cell has to work to make a reaction happen

Question 6

internal energy

Answer 6

capacity of a system to do work

Question 7

exothermic reaction

Answer 7

releases energy

internal energy of products less than reactants

Question 8

endothermic reaction

Answer 8

internal energy of products greater than reactants

energy absorbed

Question 9

enthalpy

Answer 9

heat released by a chemical reaction

Question 10

enthalpy change

Answer 10

energy released by a reaction minus work released to surroundings

Question 11

entropy

Answer 11

measures how disordered a system is

Question 12

microstate

Answer 12

arrangement of each molecule in the system at a single instant

Question 13

Gibbs free energy

Answer 13

maximum useful work we can extract from a process in an open system

Question 14

reaction rate

Answer 14

change in concentration of a reactant or product with time

Question 15

kinetic law

Answer 15

molecules will react if they collide with sufficient kinetic energy to overcome an activation barrier

Question 16

particle speed depends on…

Answer 16

mass and temperature

Question 17

first order reaction

Answer 17

decomposition

e.g. radioactive decay

Question 18

second order reaction

Answer 18

2 molecules collide to determine rate

Question 19

what is free H+ also known as?

Answer 19

hydroxonium / H3O

Question 20

acid

Answer 20

substance that produces H+ ions by dissociation

Question 21

base

Answer 21

substance that releases hydroxide ions

Question 22

buffers

Answer 22

large vol of weak acid w conjugate base

large vol of weak base w conjugate acid

Question 23

pKa

Answer 23

how strong a buffer is

Question 24

henderson hasselbach equation

Answer 24

describes how pH differs in a buffer

Question 25

free energy in a system

Answer 25

weighted sum of partial molar gibbs energy aka chemical potential of each component

Question 26

nernst potential

Answer 26

voltage difference across membrane caused by transferring just enough permanent ions to create an electrostatic barrier against further flow of ions

Question 27

osmotic pressure

Answer 27

stretching force on cell membrane caused by an imbalance of ions on either side