Biology Macromolecules Quiz

Macromolecules

• Macromolecules are large molecules formed from smaller organic molecules.
• All living things are composed of carbohydrates, lipids, proteins, and nucleic acids.
• These macromolecules consist of thousands of atoms.

Polymers and Monomers

• Macromolecules are often polymers.
• Polymers are long chains of repeating molecular units called monomers.
• Monomers are often similar or identical.
• Polymers are formed through condensation (dehydration) reactions.
• Monomers are joined by the removal of a water molecule.
• Polymers are broken down via hydrolysis reactions.
• These reactions require water.

Carbohydrates

• Carbohydrates serve as fuel and building material.
• Monosaccharides are simple sugars.
• Disaccharides are formed from two monosaccharides.
• Polysaccharides are polymers of monosaccharides.
• Common monosaccharides: Glucose, Fructose, Galactose.
• Common disaccharides: Maltose, Sucrose, Lactose.
• Common polysaccharides: Starch, Glycogen, Cellulose.
• Starch is a storage polysaccharide.
• Glycogen is a storage polysaccharide in animals.
• Cellulose is a structural polysaccharide in plants.

Lipids

• Lipids are a diverse group of hydrophobic molecules.
• Lipids are not polymers.
• Major functions of lipids: Energy storage, structural components of cell membranes, signaling molecules.
• Fats are constructed from glycerol and fatty acids.
• A fat molecule is a triacylglycerol or triglyceride.
• Saturated fats have no double bonds.
• Unsaturated fats have one or more double bonds.
• Phospholipids are major components of cell membranes.
• Composed of two fatty acid tails and a phosphate group.
• Steroids include cholesterol and hormones.
• Four fused carbon rings.

Proteins

• Proteins are the most structurally complex molecules.
• Polymers of amino acids (20 different types).
• Amino acids have an amino group and a carboxyl group.
• Four levels of protein structure: Primary, secondary, tertiary, and quaternary.
• Primary: Amino acid sequence.
• Secondary: Coils and folds in the polypeptide chain (a-helix, ß-pleated sheet).
• Tertiary: Three-dimensional arrangement of a polypeptide chain.
• Quaternary: Aggregation of multiple polypeptide chains.
• Protein conformation determines protein function.
• Protein structure can be disrupted (denatured) by changes in the environment.

Nucleic Acids

• Store and transmit hereditary information.
• Two types: DNA and RNA.
• Polymers of nucleotides.
• Nucleotides have a nitrogenous base, a pentose sugar, and a phosphate group.
• DNA is a double helix.
• Complementary base pairing (A with T, G with C).
• RNA is single-stranded.
• mRNA acts as an intermediary in protein synthesis.