bio 2 - lecture 1

where are protons located and what are their charges?

• nucleus

• positive

where are neutrons located and what are their charges?

• nucleus

• neutral

where are electrons located and what are their charges?

• orbitals

• negative

what are the symbols and names of the 6 core elements in biomolecules?

• Carbon (C)

• Hydrogen (H)

• Oxygen (O)

• Nitrogen (N)

• Phosphorus (P)

• Sulfur (S)

what does r mean in a chemical structure?

rest of the molecule

how many bonds does carbon make?

4

how many bonds does hydrogen make?

1

how many bonds does oxygen make?

2

how many bonds does nitrogen make?

3

how many bonds does phosphorus make?

5

how many bonds does sulfur make?

2

electronegativity

due to specific atomic structures, each element has a tendency to hold on to it’s valence electrons

what is the most electronegative atom & what is it’s value?

• fluorine

• 4.0

carbon EN value

2.5

hydrogen EN value

2.1

oxygen EN value

3.5

nitrogen EN value

3.1

phosphorus EN value

2.1

sulfur EN value

2.4

ionic bonds + change in EN + charge separation?

• no electron sharing (one atom has taken the electron from another atom)

• 1.9 or greater

• yes

non-polar covalent bonds + change in EN + charge separation?

• electrons are shared equally between 2 atoms

• 0-0.4

• no

polar covalent bonds + change in EN + charge separation?

• electrons are shared unequally between 2 atoms

• 0.5-1.8

• partial

what functional group is this structure and what are it’s properties

• hydroxyl

• polar

what functional group is this structure and what are it’s properties

• methyl

• nonpolar

what functional group is this structure and what are it’s properties

• carbonyl

• polar

what functional group is this structure and what are it’s properties

• carboxyl

• charged, ionizes to release H+, acidic

what functional group is this structure and what are it’s properties

• amino

• charged, accepts H+ to form NH3+, basic

what functional group is this structure and what are it’s properties

• phosphate

• charged, ionizes to release H+, acidic

what functional group is this structure and what are it’s properties

• sulfanyl

• moderately polar

hydrogen bond donor

needs a hydrogen atom bonded to a strong electronegative atom

hydrogen bond acceptor

needs a lone pair of electrons on a strong electronegative atom

which functional groups can have a h-bond interaction with water?

• hydroxyl

• carbonyl

• carboxyl

• amino

• phosphate

which functional groups cannot have a h-bond interaction with water?

• methyl

how do interactions between functional groups occur?

• happen within and between molecules that aren’t H2O