1.3 Carbon & the Chemistry of Life

Carbon

• 4 valence electrons

• tetravalence - 4 covalent bonds

• carbon can make many complex things

Carbon Stability

• NOT electronegative → can make non-polar mlc.(have balanced charge throughout molecule)

• Hydrocarbons - compounds made entirely of carbon & hydrogen

  • hydrophobic

  • carbon-carbon bonds are very strong

Chemistry of life (what chemicals make up life)

CHONP(S)

Functional Groups

1. Hydroxyl

2. Sulfhydryl

3. Methyl

4. Carbonyl

5. Carboxyl

6. Amino

   1. Phosphate

Hydroxyl

• polar

• hydrophilic (bc oxygen’s electronegativity)

req.

• has OH

Sulfhydryl

• polar

• hydrophilic (Sulfur is electronegative)

req.

• has S & H

Methyl [group]

• non-polar

• hydrophobic (no electroneg. elements)

req.

• has H & C

Carbonyl

• polar

• hydrophilic (bc oxygen electroneg.)

req.

• central C & O

• bound to 2 organic side grps

• double bond to O increases polarity

Carboxyl

• like a carbonyl + hydroxyl = carboxyl

• charged, ionized to release H+ → acidic

req.

• O & OH bound to same central C

note

• hydrogen may be missing (released) and OH → O-

Amino

• charged, accepts H+ to form NH3+

• basic

req.

• anything with an N w/ only single bonds

note

• an amino may have an N+ (single) bonded to 3 R groups and 1 H

Phosphate

• acidic; releases H+ and is charged

req.

• has a P

note

• H may be missing (released) so OH → O-

BPQ

The properties of an amino acid is determined by its R group. The R group for the amino acid alanine is a methyl group. Where are you likely to find this amino acid?

Methyl is non-polar, so alanine will be found somewhere without water b/c it’s hydrophobic!

Macromolecules

• large mlc. composed mostly of covalently bonded atoms

4 Types

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic Acids

Polymers

a mlc. consisting of repeating subunits (monomers)

Hydrolysis

process of breaking polymers into monomers by adding water

hydro = water

lysis = break down

Dehydration Synthesis (Condensation)

process of removing water (dehydration) from monomers to create a polymer

dehydration = remove water

synthesis = creation

Carbohydrates

Monomer: monosaccharides

Polymer: polysaccharides

Bond Name: glycosidic bond

Elements: CHO

Proteins

Monomer: Amino Acids

Polymer: polypeptide

Bond Name: peptide bond

Elements: CHON(S)

Nucleic Acid

Monomer: nucleotide

Polymer: DNA, RNA

Bond Name: phosphodiester bond

Elements: CHONP

Lipids

Monomer: n/a

Polymer: n/a

Bond Name: n/a

Elements: CHO(P)

• lipids don’t really make big polymers