Nucleic Acids - Vocabulary

Vocabulary flashcards covering key nucleic acid concepts from the lecture notes.

Nucleic acid

Macromolecule formed from nucleotides; includes DNA and RNA; stores and transmits genetic information.

Nucleotide

Monomer of nucleic acids consisting of a sugar, a phosphate group, and a nitrogenous base.

DNA (deoxyribonucleic acid)

Nucleic acid with deoxyribose; typically double-stranded and stores genetic information.

RNA (ribonucleic acid)

Nucleic acid with ribose; usually single-stranded and involved in protein synthesis.

Deoxyribose

Five-carbon sugar lacking an OH group at the 2' position; found in DNA.

Ribose

Five-carbon sugar with a hydroxyl at the 2' position; found in RNA.

Nitrogenous base

Organic base in nucleotides; includes A, C, G, T, U.

Purine

Two-ring nitrogenous bases (A and G).

Pyrimidine

Single-ring nitrogenous bases (C, T, U).

Adenine (A)

Purine base; pairs with Thymine in DNA or Uracil in RNA; forms two hydrogen bonds with T/U.

Thymine (T)

Pyrimidine base in DNA; pairs with Adenine; not present in RNA.

Cytosine (C)

Pyrimidine base; pairs with Guanine.

Guanine (G)

Purine base; pairs with Cytosine.

Uracil (U)

Pyrimidine base in RNA; pairs with Adenine.

Base pairing

Specific pairing rules: A with T (or U in RNA); C with G.

Hydrogen bond

Weak bonds between bases that stabilize the DNA double helix; 2 bonds in A–T/U and 3 bonds in C–G.

Phosphodiester bond

Covalent bond linking adjacent nucleotides to form the backbone of DNA/RNA.

5' to 3' direction

Direction of nucleotide linkage; polymerization occurs from 5' phosphate end to 3' hydroxyl end.

Antiparallel

Two DNA strands run in opposite 5'→3' directions.

Double helix

Shape of DNA formed by two antiparallel strands wound around each other.

Semi-conservative replication

Each new DNA molecule contains one old strand and one new strand.

mRNA

Messenger RNA; carries genetic information from DNA to the ribosome for protein synthesis.

tRNA

Transfer RNA; delivers amino acids to the ribosome during translation.

rRNA

Ribosomal RNA; structural and catalytic component of ribosomes.

Complementary base pairing

A pairs with T (or U in RNA); C pairs with G; Purines pair with Pyrimidines.

DNA sugar difference (deoxyribose vs ribose)

DNA contains deoxyribose (lacks 2' OH); RNA contains ribose (has 2' OH).