Amino acids, proteins and DNA (A-level only) key terms

Amino acid

A molecule that contains both an amine group (-NH2) and a carboxylic acid group (-COOH). In Amino acids and proteins (A-level only), Amino acid is used to explain describe amino acids as molecules containing amine and carboxylic acid groups with A-Level Chemistry precision.

Zwitterion

A dipolar ion formed when an amino acid has both a positive charge on the amine group and a negative charge on the carboxylic acid group.

zwitterion

A zwitterion is a molecule that contains both positive and negative charges but is overall electrically neutral.

amino acid

An amino acid is an organic compound that contains both an amine group (-NH2) and a carboxylic acid group (-COOH).

peptide bond

A covalent bond formed between the carboxyl group of one amino acid and the amino group of another, resulting in the release of a water molecule.

condensation reaction

A chemical reaction where two molecules combine to form a larger molecule, with the loss of a small molecule, typically water.

hydrolysis

The chemical process in which water is used to break down the bonds of a particular substance, such as proteins, into smaller molecules.

peptide bond

The covalent bond formed between the carboxyl group of one amino acid and the amino group of another, resulting in the formation of a dipeptide and releasing a molecule of water.

DNA nucleotide

A DNA nucleotide consists of a deoxyribose sugar, a phosphate group, and a nitrogenous base.

nitrogenous base

A nitrogenous base is a component of DNA nucleotides that can be adenine, thymine, cytosine, or guanine, which pair to form the rungs of the DNA ladder.

condensation reaction

A chemical reaction where two molecules combine to form a larger molecule, releasing a small molecule such as water.

sugar-phosphate backbone

The structural framework of DNA and RNA, consisting of alternating sugar and phosphate groups linked by phosphodiester bonds.

complementary base pairing

The specific hydrogen bonding between nitrogenous bases in DNA, where adenine pairs with thymine and guanine pairs with cytosine.

hydrogen bonds

Weak attractions between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom, crucial for stabilizing the DNA double helix structure.

DNA structure

The arrangement of nucleotides in a double helix that encodes genetic information. In DNA chemistry (A-level only), DNA structure is used to explain link DNA structure to information storage with A-Level Chemistry precision.

information storage

The capacity of DNA to hold and transmit genetic information through sequences of nucleotides.