Biomolecules: Carbohydrates, Lipids, and Cell Membranes (Lecture Notes)

A vocabulary set derived from the lecture notes covering chitin, cellulose, carbohydrates, lipids, fatty acids, phospholipids, cell membranes, polar/nonpolar concepts, biomolecule elements (N, P), nucleic acids, proteins, cell theory, and cytoplasm.

Chitin

A structural polysaccharide found in fungal cell walls and arthropod exoskeletons; an example of a carbohydrate not limited to animals.

Cellulose

A structural carbohydrate that makes up plant cell walls and provides rigidity.

Carbohydrates

Biomolecules used for energy storage and structural support; include sugars and polysaccharides.

Lipids

A diverse group of hydrophobic biomolecules (fats, oils) that store energy, cushion organs, and provide insulation.

Saturated fatty acids

Fatty acids with no double bonds; straight chains that pack tightly, usually solid at room temperature.

Unsaturated fatty acids

Fatty acids with one or more double bonds; kinked chains that prevent tight packing, usually liquid at room temperature.

Phospholipid

A lipid with a hydrophilic (polar) head and a hydrophobic (nonpolar) tail; essential building block of cell membranes.

Cell membrane

Phospholipid bilayer that surrounds cells; polar heads face water outside and inside, nonpolar tails form the interior.

Polar

Describes a molecule or region that is hydrophilic and interacts well with water due to partial charges.

Nonpolar

Describes a molecule or region that is hydrophobic and does not interact well with water.

Nitrogen in biomolecules

Presence of nitrogen generally indicates proteins or nucleic acids; carbohydrates and lipids typically lack nitrogen.

Phosphorus in biomolecules

Presence of phosphorus is common in nucleic acids and phospholipids (e.g., DNA/RNA backbone and phospholipid heads).

Nucleic acids

Biomolecules (DNA and RNA) that store and transmit genetic information; contain nitrogenous bases and a phosphate backbone.

Proteins

Biomolecules built from amino acids; perform diverse cellular functions; contain nitrogen in amino groups.

Cell theory

Principle that all living things are made of cells; cells are the basic unit of life; new cells arise from existing cells.

Cytoplasm

The water-based interior of the cell where most metabolic processes occur; surrounds organelles.