Chapter 3: Biological Macromolecules - Key Terms

Overview

• Focus on key biological macromolecules necessary for life.
• Includes carbohydrates, proteins, lipids, and nucleic acids.
• Discusses structure and function of these macromolecules.

Key Terms:

Proteins

• Amino Acid: Monomer of proteins. Contains a central carbon atom, an amino group, a carboxyl group, a hydrogen atom, and an R group.
• Protein: Biological macromolecule composed of one or more chains of amino acids.
• Peptide Bond: Covalent bond formed between two amino acids.
• Primary Structure: Linear sequence of amino acids in a protein.
• Secondary Structure: Regular folding pattern of proteins (e.g., alpha-helix, beta-pleated sheet).
• Tertiary Structure: Three-dimensional shape of a protein, including interactions between secondary structures.
• Quaternary Structure: Association of multiple polypeptide chains in a protein.
• Denaturation: Loss of protein structure due to changes in temperature, pH, or chemical exposure.
• Chaperone: Protein that assists in the proper folding of other proteins.

Carbohydrates

• Monosaccharide: Single sugar molecule (e.g., glucose).
• Disaccharide: Two sugar molecules covalently bonded.
• Polysaccharide: Long chain of monosaccharides (e.g., starch, glycogen, cellulose).
• Glycosidic Bond: Bond formed between sugar molecules.
• Cellulose: Structural polysaccharide in plant cell walls.
• Chitin: Structural polysaccharide in arthropod exoskeletons and fungi cell walls.

Lipids

• Lipid: Non-polar macromolecule, insoluble in water.
• Phospholipid: Major component of cell membranes, consisting of two fatty acids and a phosphate group attached to glycerol.
• Steroid: Lipid molecule with four fused carbon rings.
• Saturated Fatty Acid: Fatty acid with no double bonds between carbon atoms.
• Unsaturated Fatty Acid: Fatty acid with one or more double bonds in the carbon chain.
• Trans Fat: Unsaturated fat that has been artificially hydrogenated.

Nucleic Acids

• Nucleic Acid: Macromolecule that stores genetic information, composed of nucleotides (DNA, RNA).
• Nucleotide: Monomer of nucleic acids, consisting of a pentose sugar, phosphate group, and nitrogenous base.
• DNA (Deoxyribonucleic Acid): Carrier of genetic information, double-helical structure.
• RNA (Ribonucleic Acid): Single-stranded nucleic acid involved in protein synthesis.
• mRNA (Messenger RNA): RNA that carries genetic information from DNA to the ribosome.
• rRNA (Ribosomal RNA): RNA that forms part of the ribosome and catalyzes protein synthesis.
• tRNA (Transfer RNA): RNA involved in translation, carries amino acids to ribosome.

Processes

• Dehydration Synthesis: Reaction that links monomers, releasing water.
• Hydrolysis: Reaction that breaks down polymers into monomers using water.
• Transcription: Formation of RNA from a DNA template.
• Translation: Process by which RNA directs protein synthesis at ribosomes.

Additional Notes

• Biological macromolecules are crucial for cellular structure and function.
• Understanding macromolecule structure aids in understanding their role in biological processes.
• Each macromolecule type has unique roles and properties that are essential for life.