BIO 2 Functional Group vocabs and structure

DEFINE functional groups

specific repeated combination of atoms (usually parts of molecule) that have distinct properties (responsible for a characteristic of that molecule) and are often found in many biomolecules

DESCRIBE functional groups (give list of example functional groups)

1. Amino Group

2. Carboxyl Group

3. Hydroxyl Group

4. Methyl Group

5. Carbonyl Group

6. Thiol (a.k.a Sulfanyl) Group

7. Phosphate Group

EXPLAIN Hydroxyl Group

• OH group covalently bonded to another atom (R — OH)

• often, but not always bound to C atom; but, both C and H atoms will be attached towards O atom b/c of its large EN → making hydroxyl groups polar covalent bonds

EXPLAIN Carboxyl Group

• combination of carbonyl and hydroxyl group attached to the same carbon → new characteristic recognized as carboxylic

• carboxyl can ionize (likely to give up e-), which means it can act as a ACID and release H⁺ atom from the hydroxyl group as a free proton (H⁺) → results in delocalized negative charge on remaining O atoms

What kind of interaction does carboxyl have with protons (H⁺)?

Carboxyl is a proton DONOR and ACCEPTOR

What does it mean for a functional group to be both a proton donor and acceptor?

When a functional group serves as both a proton acceptor and donor, it means that it can flip-flop b/w protonated (R-COOH) and deprotonated (R-COO^-) after donating H⁺ depending on the pH of the solution

EXPLAIN Amino Group

• organic compound containing an amino group is called an amine (R — NH3)

• like O, N is more EN than C and H → results in the amino groups displaying some polar characteristic

What kind of interaction does the Amino Group have with protons (H⁺)?

• Amino is a proton ACCEPTOR

  • can act like a BASE, bond w/ a fourth H atom → N atom becomes positively charged and form ionic bonds

EXPLAIN Phosphate Group

• the O atom bonded w/ the P atom is more EN, making the phosphate group are polar covalent bonds

• commonly in nucleic acids and on phospholipids (make up the lipid bilayers in cells)

How else does the O atom’s high EN interact with its surrounding atoms?

the polar characteristic and large EN value of the O allows the O atoms to form HB (INTERmolecular (like a elastic force, not magnetic) w/ near by H atoms with a 𝛅⁺ (from forming a intramolecular (covalent) bond with another atom with a high EN

EXPLAIN Methyl Group

• In a NON POLAR bond or molecule, e^- and charge will be relatively evenly distributed

• derived from methane molecule, consist of one C atom and 3 H atom (R — CH3)

How does the methyl group interact with its surrounding atoms/materials

b/c the C-H3 bonds are effectively NP bond, methyl groups can’t form HBs and won’t interact with/ polar compounds (i.e. H2O)

What functional group is this?

carboxyl group

• combination of a carbonyl and hydroxyl group

What functional group is this?

phosphate group

What functional group is this?

methyl group

What functional group is this?

amino group: amine

EXPLAIN amine group

• has a nitrogen atom directly bonded directly to alkyl groups

• NO carbonyl group attached

• BASIC

What functional group is this?

amino group: amide (carboxyamide)

EXPLAIN amide group

• derivatives of carboxylic ACID

  • ACIDIC

• nitrogen atom directly attached to a carbonyl group (C=O)

What functional group is this?

hydroxyl group