Functional Groups for Chapter 4

Hydroxyl

—OH or HO—

Hydroxyl

Polar due to electronegative oxygen. Forms hydrogen bonds with water, helping dissolve compounds such as sugars.

Hydroxyl

Compound name: Alcohol

Carbonyl

C==O

Carbonyl

Sugars with ketone groups are called ketoses. Those with aldehydes are called aldoses.

Carbonyl

Compound name: Ketone (if the group is within a carbon skeleton) or Aldehyde (if the group is at the end of a carbon skeleton)

Carboxyl

—COOH

Carboxyl

Acts as an acid because the covalent bond between oxygen and hydrogen is so polar.

Carboxyl

Compound name: _____ic acid or organic acid

Sulfhydryl

—SH

Sulfhydryl

Groups can react, forming “cross-link” stabilizing protein structure.

Sulfhydryl

Compound name: Thiol

Phosphate

—OPO₃²⁻

Phosphate

Contributes negative charge (1- when inside a chain, 2- when at the end). When attached, confers on a molecule the ability to react with water, releasing energy.

Phosphate

Compound name: Organic _____

Methyl

—CH₃

Methyl

Affects the expression of genes when on DNA or on proteins bound to DNA.

Methyl

Compound name: ____ated compound