Lectures 5-9: Lipids, Nucleic Acids, Proteins & Enzymes (Vocabulary Flashcards)

Vocabulary flashcards covering key terms from lipids, biomembranes, nucleic acids, and proteins/enzyme topics from Lectures 5-9.

Phospholipid

A lipid with two fatty acid tails, a glycerol backbone, and a phosphate-containing head; major membrane component.

Glycerol

Three-carbon backbone used to attach fatty acids and phosphate in lipids.

Fatty acid

Hydrocarbon chains that form the hydrophobic tails of phospholipids.

Triglyceride

Glycerol linked to three fatty acids; primary energy storage lipid.

Glycerophospholipid

Phospholipid with glycerol backbone and a phosphate-containing head group.

Hydrophilic

Water-loving; head region of phospholipids that interacts with water.

Hydrophobic

Water-fearing; fatty acid tails that avoid water.

Lipid bilayer

Two-layer sheet of phospholipids forming the structural basis of membranes, with tails inward.

Membrane fluidity

Dynamic, fluid nature of membranes allowing lateral movement of components.

Phase transition

Transition between fluid and gel states in lipid membranes; influenced by composition and temperature.

Steroid

Lipid class with four fused hydrocarbon rings; includes cholesterol and other steroids.

Amphipathic

Molecule with both hydrophilic and hydrophobic regions (e.g., phospholipids).

Liposome

Spherical vesicle formed by lipid bilayers, used to study lipid properties.

Van der Waals forces

Weak intermolecular forces contributing to lipid packing and membrane stability.

Hydrophobic interactions

Tendency of nonpolar regions to associate away from water, driving folding/assembly.

Nucleotide

Nucleic acid monomer consisting of a sugar, phosphate, and a nitrogenous base.

Nucleoside

Sugar bound to a nitrogenous base, without a phosphate group.

Deoxyribonucleotide

DNA nucleotide with deoxyribose sugar.

Ribonucleotide

RNA nucleotide with ribose sugar.

Deoxyribose

Five-carbon sugar lacking the 2'-OH group (DNA).

Ribose

Five-carbon sugar with hydroxyl groups (RNA).

Purine

Double-ring bases: Adenine and Guanine.

Pyrimidine

Single-ring bases: Cytosine and Thymine (DNA); Uracil (RNA).

Adenine

Purine base; pairs with Thymine in DNA and with Uracil in RNA.

Guanine

Purine base; pairs with Cytosine.

Cytosine

Pyrimidine base; pairs with Guanine.

Thymine

Pyrimidine base; DNA-specific; pairs with Adenine.

Uracil

Pyrimidine base; RNA-specific; pairs with Adenine.

DNA

Deoxyribonucleic acid; usually double-stranded; stores genetic information.

RNA

Ribonucleic acid; usually single-stranded; involved in protein synthesis and gene expression.

dNTPs

Deoxyribonucleoside triphosphates; building blocks for DNA synthesis.

Phosphodiester bond

Backbone linkage between nucleotides via phosphate groups in DNA/RNA.

Amino acid

Monomer of proteins; contains an amino group, a carboxyl group, and a variable side chain.

Peptide bond

Bond between amino acids formed by a dehydration synthesis reaction.

Polypeptide

Long chain of amino acids; a protein or protein fragment.

Primary structure

Linear sequence of amino acids in a protein.

Secondary structure

Local folding patterns stabilized by hydrogen bonds (alpha-helix, beta-pleated sheet).

Alpha-helix

Right-handed helical secondary structure stabilized by internal hydrogen bonds.

Beta-pleated sheet

Secondary structure with strands linked by hydrogen bonds forming a sheet.

Tertiary structure

Three-dimensional fold of a single polypeptide; stabilized by multiple interactions.