Functional Groups

As listed on Figure 4.10 (p. 64-65)

Hydroxyl

• —OH
• Polar (Hydrophilic)

Carbonyl

• Pronounced car-bō-NEEL
• >CO (carbon double-bonded with oxygen)
• Polar: found in sugars which are water-soluble

Carboxyl

• Carbonyl + Hydroxyl
• —COOH (carbon has two oxygen: one is double bound, other is single; single-bond oxygen has hydrogen)
• Polar (hydrophilic), always acidic because it can give up the H atom in the hydroxyl branch. (see BIOL 111 Chapter 3), found in amino acids and fatty acids

Amino

• —NH₂ (nitrogen with two hydrogens)
• polar, acts as a base because it picks up an extra H⁺ ion since N is so electronegative

Sulfhydryl

• —SH or HS—
• In some amino acids
• Important to protein structure

Phosphate

• —OPO₃^2–
  EX: Cell gets energy from adenosine triphosphate (ATP)
• Very polar
• Negatively charged
• Found in nucleic acids, ATP, and phospholipids

Methyl

• —CH₃ (carbon with three hydrogens)
• Addition to DNA/other molecules affects function of that molecule (more or less reactive; turns genes on or off)