Lectures 1-3 (Properties of Biological Molecules)

Question 1

Covalent bonds are [stronger/weaker] than noncovalent interactions.

Answer 1

Stronger

Question 2

Covalent bond length is [shorter/longer] than noncovalent interactions.

Answer 2

Shorter

Question 3

Describe the connectivity of covalent bonds.

Answer 3

Share electrons

Question 4

Describe the connevtivity of noncovalent interactions.

Answer 4

Attraction only

Question 5

Bond between monomers of proteins.

Answer 5

Peptide

Question 6

Bond between monormers of carbohydrates.

Answer 6

Glycosidic

Question 7

Bond between monomers of lipids.

Answer 7

Ester

Question 8

Bond between monomers of nucleic acids.

Answer 8

Phosphodiester

Question 9

How is bond strength measured?

Answer 9

In terms of energy needed to break bonds (i.e. can be dependent on bond length)

Question 10

Examples of charge-charge interaction.

Answer 10

Ionic bonds (i.e. NaCl), salt bridges (i.e. interaction between 2 AA in a protein)

Question 11

In a vacuum, how would you measure how attractive two ions are to each other?

Answer 11

Coulomb’s Law

Question 12

Equation for Coulomb’s Law

Answer 12

Where F = Force between ions in Newtons; q = Ion charges in Coulombs, k = 8.85 x 10^-12 C²/J*m; r = distance between nuclei

Question 13

In a biological environment, what must be accounted for when measuring how attractive two ions are to each other?

Answer 13

Relative permittvity

Question 14

Equation for measuring that attraction of two ions in a biological environment.

Answer 14

Where D = Dielectric constant

Question 15

Equation for measuring energy of interactions.

Answer 15

Question 16

Qualitative interpretation of F>0 (i.e. in terms of Coulomb’s Law).

Answer 16

Ions are repulsed

Question 17

Qualitative interpretation of F<0 (i.e. in terms of Coulomd’s Law).

Answer 17

Ions attract

Question 18

Qualitative interpretation of E<0 (i.e. in terms of energy of interaction equation).

Answer 18

Attraction

Question 19

Qualitative interpretation of E>0 (i.e. in terms of energy of interaction equation).

Answer 19

Not considered

Question 20

Nature of interaction of hydrogen bonds.

Answer 20

Share a hydrogen atom/proton.

Question 21

Type of bonds with the shortest bond length.

Answer 21

Covalent bonds

Question 22

Type of bonds with the strongest bond energy.

Answer 22

Covalent bonds

Question 23

Type of bonds with the lowest bond energies.

Answer 23

Van der Waals interactions

Question 24

What is the optimal phase state for H-bonding of water?

Answer 24

Solid (i.e low temperature, low motion/energy)

Question 25

At what point can water no longer form H-bonds?

Answer 25

When it is a gas

Question 26

List waters four unqiue properties.

Answer 26

Solid density < liquid density, changing temperature is difficult, strong surface tension, and universal solvent.

Question 27

Amount of heat energy needed to change the temperature of 1 g of a given substrate by ±1 °C.

Answer 27

Specific heat capacity (i.e. why the ocean does not freeze)

Question 28

The amount to energy needed to change 1 g of a given substance from a liquid to a gas.

Answer 28

Heat of vaporization (i.e. why sweating removes body heat)

Question 29

Property of water that permits surface tension.

Answer 29

Cohesion of water

Question 30

Properties of water that permits capillary action.

Answer 30

Both adhesion and cohesion

Question 31

The breaking/making of chemical bonds.

Answer 31

Chemical reactions

Question 32

Noncovalent interactions - Energy is [used/released] to break bonds; energy is [used/released] when bonds are formed

Answer 32

Used; Released

Question 33

Covalent interactions - Energy is [used/released] when bonds are broken, energy is [used/released] when bonds are formed.

Answer 33

Released; Used

Question 34

True/False: Equilibrium means equal concentrations.

Answer 34

False

Question 35

Dissociation constant (K_a) equation.

Answer 35

Question 36

Equation for pK_a.

Answer 36

Question 37

The larger the K_a the [weaker/stronger] the acid.

Answer 37

Stronger

Question 38

The larger the pK_a the [weaker/stronger] the acid.

Answer 38

Weaker

Question 39

[Weaker/Stronger] acids have a larger energy of interaction than its counterpart.

Answer 39

Weaker