Biomolecules: Lipids, Proteins, and Nucleic Acids (Vocabulary)

Vocabulary flashcards covering key lipid, protein, and nucleic acid concepts from the lecture notes.

Saturated fats

Fats with no double bonds in fatty acids; tend to be water-insoluble and are not strongly correlated with reduced cardiovascular/cerebrovascular disease compared to unsaturated fats.

Unsaturated fats

Fats with one or more double bonds in fatty acids; often liquid at room temperature; associated with lower risk of cardiovascular and cerebrovascular disease; cardioprotective.

LDL cholesterol

Low-density lipoprotein; carries cholesterol in the blood; higher levels correlate with cardiovascular disease; commonly called the 'bad' cholesterol.

Phospholipid

Lipid with a glycerol backbone, two fatty acids, and a phosphate group; hydrophilic head and hydrophobic tails; forms cell membranes.

Triglyceride

Lipid with a glycerol backbone and three fatty acids; water-insoluble; primary energy storage molecule.

Glycerol

Three-carbon backbone of many lipids, including triglycerides and phospholipids.

Phosphate group

Phosphate moiety in phospholipids; negatively charged; contributes to the water-solubility of the phospholipid head.

Hydrophilic

Water-loving; interacts well with water; characteristic of phospholipid heads.

Hydrophobic

Water-fearing; tails of phospholipids avoid water.

Micelles

Spherical assemblies formed by amphipathic lipids in water, with hydrophilic heads outward and hydrophobic tails inward; relevant to membrane formation.

Cell membrane

Phospholipid bilayer containing cholesterol and proteins that encloses the cell and regulates its environment.

Cholesterol

Steroid molecule essential for membranes and hormone synthesis; embedded in membranes to stabilize them; precursor to steroids and bile acids.

Steroid nucleus

Core four-ring carbon structure that underlies steroids.

Steroids

Lipids based on the steroid nucleus; include cholesterol and steroid-derived hormones.

Bile acids

Cholesterol-derived molecules that aid fat digestion by emulsification; cholesterol is a precursor.

Proteins

Macromolecules made of amino acids; perform structural, enzymatic, signaling, and immune functions; protein shape determines function.

Amino acids

Building blocks of proteins; 20 standard amino acids in humans; each has an amine group, a carboxyl group, a hydrogen, and an R (side) group.

Amine group

NH2 group on amino acids; part of the amino acid structure.

Carboxyl group

COOH group on amino acids; part of the amino acid structure.

R group (side chain)

Variable side chain on amino acids; determines properties (hydrophilic/hydrophobic, acid/base) of the amino acid.

Peptide

Short chain of amino acids (<50) linked by peptide bonds; can act as signaling molecules.

Peptide bond

Bond joining amino acids in a growing chain; formed by ribosomes during protein synthesis.

Primary structure

Linear sequence of amino acids in a protein; dictates higher-order structure and function.

Protein conformation

Three-dimensional shape of a protein; determines function; also called its conformation.

Polypeptide

Long chain of amino acids; when long enough, it constitutes a protein.

Enzymes

Proteins that act as biological catalysts to speed up chemical reactions.

Antibodies

Immune system proteins produced by plasma cells; bind pathogens to help neutralize them.

Hormones

Protein-based signaling molecules that regulate physiological processes.

Receptors

Proteins on cell surfaces or within cells that bind signals and trigger cellular responses.

Ribosome

Molecular machine that synthesizes proteins by linking amino acids via peptide bonds.

ATP

Adenosine triphosphate; energy currency of the cell; produced in cytoplasm and mitochondria; powers energy-demanding processes.

DNA

Deoxyribonucleic acid; stores genetic information; double-stranded helix; bases A, T, C, G; sugar-phosphate backbone.

RNA

Ribonucleic acid; assists in protein synthesis; typically single-stranded; bases A, C, G, U; sugar ribose.

Nucleotides

Monomers of nucleic acids; consist of a sugar, phosphate, and a nitrogenous base.

Sugar-phosphate backbone

The repeating sugar and phosphate units that form the backbone of DNA and RNA.

Base pairing

Complementary hydrogen-bonded pairing: A with T (DNA) or A with U (RNA), and C with G.

Double helix

The two anti-parallel strands of DNA twisted into a helical shape.

Hydrogen bonds

Weak bonds between base pairs that hold DNA strands together but allow separation during transcription.

Uracil

RNA base that replaces thymine and pairs with adenine.