Lecture Notes - Biochemistry & Molecular Biology (Vocabulary Flashcards)

A set of vocabulary-style flashcards covering key concepts from the lecture notes, focusing on biochemistry and molecular biology terms and definitions.

Primary structure

Linear sequence of amino acids in a polypeptide, held together by peptide bonds.

Peptide bond

Covalent bond linking amino acids in a protein backbone.

Polypeptide

A long chain of amino acids that forms the basis of a protein and has a defined primary structure.

Secondary structure

Local folding patterns in proteins, including alpha helices and beta sheets, stabilized by hydrogen bonds.

Alpha helix

A right-handed coiled structure of the polypeptide backbone stabilized by intra-chain hydrogen bonds.

Beta pleated sheet

A sheet-like arrangement of beta strands held together by hydrogen bonds between strands.

Tertiary structure

Three-dimensional shape of a single polypeptide, shaped by interactions among R groups.

Quaternary structure

Arrangement of multiple polypeptide subunits into a functional protein.

R group (side chain)

Side chain of an amino acid that determines its chemical properties and behavior.

Hydrophobic

Nonpolar amino acids that tend to cluster inside the protein away from water.

Hydrophilic

Polar or charged amino acids that interact well with water.

Polar

Molecule having regions of partial charge; often hydrophilic.

Cysteine

Amino acid containing a sulfhydryl (-SH) group capable of forming disulfide bridges.

Glycine

Amino acid with the smallest side chain (H); fits into tight spaces.

Proline

Amino acid with a restricted rotation due to a rigid ring structure, causing kinks.

Disulfide bridge

Covalent bond between two cysteine residues that stabilizes protein structure.

Cis isomer

Double bond configuration where identical substituents are on the same side.

Trans isomer

Double bond configuration where identical substituents are on opposite sides.

Purines

Double-ring nitrogenous bases; includes adenine and guanine.

Pyrimidines

Single-ring nitrogenous bases; includes cytosine, thymine, and uracil.

Adenine

Purine base; pairs with thymine in DNA or uracil in RNA; part of ATP.

Guanine

Purine base; pairs with cytosine in DNA/RNA.

Cytosine

Pyrimidine base; pairs with guanine in DNA/RNA.

Thymine

Pyrimidine base in DNA; pairs with adenine.

Uracil

Pyrimidine base in RNA; pairs with adenine (replaces thymine in RNA).

Phosphodiester bond

Bond that links nucleotides in the DNA/RNA backbone via phosphate groups.

Ester bond

Bond formed between a carboxyl group and an alcohol; general covalent bond type.

ATP (Adenosine Triphosphate)

Energy currency of the cell; adenosine with three phosphate groups; energy released on bond cleavage.

Fructose-1,6-bisphosphate

Glycolysis intermediate with two phosphate groups; formed from fructose-6-phosphate.

Glucosamine

A carbohydrate with an amino group; precursor in cartilage components.

Chitin

Structural polysaccharide of acetylglucosamine; forms exoskeletons in some insects.

Biogenetic tree (phylogenetic tree)

Diagram showing evolutionary relationships; nodes represent common ancestors; closer nodes indicate closer relatedness.

Node (in phylogenetic trees)

Branching point where lineages diverge to form separate groups.

Common ancestor

A shared predecessor from which different species or groups diverge on a phylogenetic tree.

Hydrogen bond

Weak attraction between polar molecules, often between H and N/O; crucial in secondary structure.

Van der Waals forces

Weak intermolecular forces due to temporary dipoles; vary with distance and surface area.

Ionic bond

Electrostatic attraction between oppositely charged ions; electron transfer creates charged species.