Nucleic Acids and Their Structures

Flashcards covering key concepts and vocabulary from the lecture on nucleic acids and their structures.

Nucleic Acids

Molecules made up of nucleotides that store and transfer genetic information.

Primary Structure

The order of bases in the polynucleotide sequence which specifies the genetic code.

Secondary Structure

The three-dimensional conformation of the polynucleotide backbone.

Tertiary Structure

The supercoiling of the nucleic acids.

Quaternary Structure

The interaction of nucleic acids with other macromolecules, such as proteins.

Nucleotide

Building blocks of nucleic acids, composed of a purine or pyrimidine base, a sugar, and a phosphate group.

Adenine

A purine base in nucleic acids that pairs with thymine in DNA and uracil in RNA.

Thymine

A pyrimidine base found in DNA that pairs with adenine.

Guanine

A purine base in nucleic acids that pairs with cytosine.

Cytosine

A pyrimidine base found in both DNA and RNA that pairs with guanine.

Uracil

A pyrimidine base in RNA that replaces thymine.

Phosphodiester Bond

Covalent linkage between the 3′ hydroxyl group of one nucleotide and the phosphate group of the next.

DNA Double Helix

The structure formed by two polynucleotide chains wrapped around each other, proposed by Watson and Crick.

Base Pairing

The specific pairing of nucleotide bases (adenine with thymine; guanine with cytosine) held together by hydrogen bonds.

Denaturation of DNA

The process by which the hydrogen bonds between DNA strands are broken, leading to the separation of the strands.

RNA

Single-stranded nucleic acid that acts as a messenger carrying instructions from DNA for controlling the synthesis of proteins.

mRNA

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

tRNA

Transfer RNA that brings amino acids to ribosomes during protein synthesis.

rRNA

Ribosomal RNA which, along with proteins, makes up the ribosome.

Topoisomerases

Enzymes that introduce or remove supercoils from DNA.

Chromatin

A complex of DNA and protein found in eukaryotic nuclei.

Nucleosome

A unit of DNA wrapped around a core of histone proteins, forming the basic structural unit of chromatin.

Splicing

The process of removing introns and joining exons in pre-mRNA to form mature mRNA.