Bio U1C5: Nucleic Acids

Nucleic Acids

Macromolecules that store and transmit hereditary information; blueprint for building proteins, new cells, and the next generation.

DNA

Deoxyribonucleic acid; double helix; stores genetic information; template for RNA synthesis.

RNA

Ribonucleic acid; single helix; carries instructions from DNA to make proteins.

Nucleotide

Monomer of nucleic acids; consists of a nitrogenous base, a pentose sugar, and a phosphate group.

Nitrogenous Base

Component of nucleotide that contains nitrogen and acts as a code letter (A, T, C, G, or U).

Pentose Sugar

5-carbon sugar in nucleotides; deoxyribose in DNA and ribose in RNA.

Phosphate Group

Negatively charged component of a nucleotide; forms part of the sugar-phosphate backbone.

Purine

Double-ring nitrogenous base; includes adenine (A) and guanine (G).

Pyrimidine

Single-ring nitrogenous base; includes cytosine (C), thymine (T, DNA only), and uracil (U, RNA only).

Sugar-Phosphate Backbone

Repeating pattern of sugars and phosphates that forms the structural framework of nucleic acid polymers.

Phosphodiester Bond

Covalent bond connecting the phosphate group of one nucleotide to the sugar of the next; forms the backbone of nucleic acids.

Base Pairing

Specific hydrogen bonding between nitrogenous bases: A pairs with T (or U in RNA), and C pairs with G.

Hydrogen Bonds

Weak bonds between complementary nitrogen bases that hold the two strands of DNA together.

Complementary Strands

The two strands of DNA are complementary, allowing each strand to serve as a template for replication.

DNA Replication

Process of copying DNA before cell division; each strand serves as a template for a new complementary strand.

ATP (Adenosine Triphosphate)

Modified nucleotide used for energy transfer in cells; composed of adenine, ribose, and three phosphate groups.

A-T Base Pair

Pair of adenine and thymine held together by two hydrogen bonds.

G-C Base Pair

Pair of guanine and cytosine held together by three hydrogen bonds; higher G-C content increases DNA stability.

Central Dogma

Flow of genetic information: DNA → RNA → Protein.