BIO C2 – Biological Macromolecules & Water Properties

Vocabulary flashcards summarizing key terms from BIO C2 lecture on water properties and biological macromolecules.

Element

A pure substance made of only one kind of atom; examples important to biology include carbon, oxygen, hydrogen, and nitrogen.

Carbon

Central element in organic chemistry; found in all organic molecules due to its four valence electrons allowing diverse bonding.

Oxygen

Element essential for aerobic respiration and present in water and most biological molecules.

Hydrogen

Lightest element; part of water and almost all organic compounds.

Nitrogen

Element found in proteins and nucleic acids, critical for amino and nucleic structures.

Molecule

Two or more atoms chemically bonded together.

Organic Molecule

Carbon-based molecule such as carbohydrates, proteins, lipids, and nucleic acids.

Inorganic Molecule

Molecule not primarily carbon-based; exceptions include CO₂ and CO.

Polar Molecule

Molecule with uneven charge distribution, giving it positive and negative ends (e.g., water).

Nonpolar Molecule

Molecule with electrons shared evenly, lacking overall charge (e.g., lipids).

Biological Macromolecule

Large organic polymer; includes carbohydrates, proteins, nucleic acids, and lipids.

Polymer

Large molecule composed of repeating monomer units.

Monomer

Small building-block molecule that joins with others to form a polymer.

Polymerisation

Process of linking monomers into polymers.

Dehydration Synthesis

Chemical reaction that joins monomers by removing water; also called a dehydration reaction.

Hydrolysis

Chemical reaction that breaks polymers into monomers by adding water.

Water (H₂O)

Small polar inorganic compound critical for life; exhibits unique properties due to hydrogen bonding.

Hydrogen Bond

Weak attraction between a hydrogen atom and an electronegative atom; responsible for water’s special properties.

Adhesion

Water molecules sticking to other surfaces.

Cohesion

Water molecules sticking to each other.

Universal Solvent

Property of water enabling it to dissolve many substances.

High Specific Heat

Water property requiring much energy to change temperature, stabilizing environments.

High Heat of Evaporation

Water property requiring large energy input to vaporize, providing cooling.

Ice Less Dense than Liquid Water

Allows ice to float, protecting aquatic life in cold climates.

Carbohydrate

Organic ‘sugar’ molecule with C:H:O ratio 1:2:1; key energy source and structural component.

Monosaccharide

Single-sugar monomer; examples: glucose, galactose, fructose.

Disaccharide

Two monosaccharides linked; examples: maltose, lactose, sucrose.

Polysaccharide

Complex carbohydrate of many monosaccharides; e.g., starch, glycogen, cellulose, chitin.

Glucose

Primary energy monosaccharide (C₆H₁₂O₆).

Galactose

Monosaccharide that combines with glucose to form lactose.

Fructose

Fruit sugar monosaccharide that combines with glucose to form sucrose.

Maltose

Disaccharide of glucose + glucose.

Lactose

Disaccharide of glucose + galactose; milk sugar.

Sucrose

Disaccharide of glucose + fructose; table sugar.

Starch

Plant storage polysaccharide of glucose.

Glycogen

Animal storage polysaccharide of glucose.

Cellulose

Structural polysaccharide in plant cell walls.

Chitin

Structural polysaccharide in fungal cell walls and arthropod exoskeletons.

Nucleic Acid

Polymer that stores and transmits genetic information; DNA or RNA.

Nucleotide

Monomer of nucleic acids; consists of sugar, phosphate, and nitrogen base.

Phosphodiester Bond

Covalent bond linking nucleotides in DNA or RNA.

DNA (Deoxyribonucleic Acid)

Double-stranded nucleic acid with bases A, G, C, T and deoxyribose sugar; stores genetic code.

RNA (Ribonucleic Acid)

Single-stranded nucleic acid with bases A, G, C, U and ribose sugar; involved in protein synthesis.

Protein

Polymer of amino acids performing structural and functional roles.

Amino Acid

Protein monomer containing amino group, carboxyl group, and variable R group.

R Group (Side Chain)

Variable group in amino acids determining polarity and properties.

Peptide Bond

Covalent bond linking amino acids in a polypeptide.

Polypeptide

Chain of amino acids; folds into functional protein.

Fibrous Protein

Structural protein (e.g., keratin, collagen).

Globular Protein

Functional protein (e.g., haemoglobin, enzymes).

Lipid

Hydrophobic biomolecule group including fats, phospholipids, and steroids.

Fat (Triglyceride)

Lipid formed by glycerol and three fatty acids; long-term energy storage.

Phospholipid

Lipid with hydrophilic head and hydrophobic tails; forms cell membranes.

Phospholipid Bilayer

Double layer of phospholipids composing biological membranes.

Steroid

Lipid with four carbon-ring structure; includes hormones and cholesterol.

Hydrophobic

Water-repelling; characteristic of nonpolar molecules like lipids.

Hydrophilic

Water-attracting; characteristic of polar molecules or regions.

Saturated Fat

Fatty acid with only single C–C bonds; usually solid at room temperature.

Unsaturated Fat

Fatty acid with one or more C=C double bonds; usually liquid at room temperature.

Monounsaturated Fat

Unsaturated fat with one double bond in fatty acid chain.

Polyunsaturated Fat

Unsaturated fat with multiple double bonds in fatty acid chain.