O'Leary Lecture 1

Question 1

What can we use to measure atoms, ribosomes, viruses, anything from 0.1 nm to 100 nm?

Answer 1

x-ray diffraction

Question 2

What measures molecules from 0.1 nm to 10 nm?

Answer 2

NMR

Question 3

What wavelength can an electron microscope measure?

Answer 3

0.1 nm to 100 µm

Question 4

What can a light microscope measure?

Answer 4

100 nm to 1 mm

Question 5

How small can the human eye see?

Answer 5

a little less than 1 mm

Question 6

How does biology techniques vary with time?

Answer 6

Functions operate across a wide range of time scales, from bond vibration (10^-14 s) to movement of molecules around the cell (1 s)
- enzyme turnover rates
- cell doubling
- animal lifespan

Question 7

What are the building blocks of protein and ribosomes?

Answer 7

Protein: amino acids
Ribosome: Nucleotide

Question 8

What are macromolecules?

Answer 8

Polymers, smaller molecules/building blocks combined into a large compound

Question 9

How do we measure structure-function relationships?
Ex. enzyme activity, receptor/ligand binding, intracellular localization

Answer 9

Need a physical property that acts as a reporter for the structure or function of interest
- equilibrium/stability: thermodynamics
- approaching equilibrium: kinetics

Question 10

What is spectroscopy?

Answer 10

Study of interaction of matter with electromagnetic radiation

Question 11

What are the restrictions of spectroscopy?

Answer 11

• sensitivity
• selectivity
• time resolution
• non-destructive
• broad range of complementary measurement methods

Question 12

How does electromagnetic radiation work?

Answer 12

• Oscillating electric field
• Orthogonal oscillating magnetic field
• waves that oscillates at right angled to its direction of propagation (transverse)
• directional
• characterized by wavelength

Question 13

What is the energy equation characterized by wavelength?

Answer 13

E = hc/λ
h = planck’s constant = 6.62610^-34 Js
c = speed of light = 3.010^8 m/s
energy is inversely proportional to wavelength

Question 14

How is wavelength related to momentum?

Answer 14

λ = h/p
h = planck’s constant = 6.626*10^-34 Js
p = momentum

Question 15

What is the relationship between light and energy?

Answer 15

E = hv
h = planck’s constant = 6.626*10^-34 Js
v = frequency
energy difference between the initial and charge-redistributed states and the energy of the radiation must be equal.

Question 16

How are atoms distributed?

Answer 16

Nucleus = heavy, positively charged
Electrons = light, negatively charged

Question 17

How are electrons distributed between atoms?

Answer 17

Covalent bonds
- equilibrium positions of the particles represents a balance of attractive and repulsive forces between negatively charged electrons and positive nuclei

Question 18

What happens if the electron cloud is distributed asymmetrically?

Answer 18

Molecule is considered polar and has a dipole. The dipole moment is a vector with a direction determined by the shape of the molecule.

Question 19

What happens when light is introduced?

Answer 19

When the perturbation results in an allowed quantum mechanical state of the molecule, energy from the EM radiation will be absorbed.