2B: Nucleic acids Flashcards
Nucleic acid
The class of macromolecule that includes DNA and RNA. All nucleic acids are polymers made out of nucleotide monomer subunits.
Polymer
A large molecule that is made up of small, repeated monomer subunits.
Nucleotide
The monomer subunit of nucleic acids made up of
- a nitrogen-containing base(ATGC)
- a five-carbon sugar molecule (ribose in RNA and deoxyribose in DNA)
- a phosphate group.
- Only added to the 3’ end
Monomer
A molecule that is the smallest building block
of a polymer.
DNA (deoxyribonucleic acid)
A double-stranded nucleic acid chain made up of nucleotides. Carries the instructions for proteins which are required for cell and organism survival.
RNA (ribonucleic acid)
A single-stranded nucleic acid chain made up of nucleotides including:
- mRNA
- rRNA
- tRNA.
Phosphodiester bond
A strong covalent bond linking a five-carbon sugar to a phosphate group.
Condensation reaction
A reaction where two monomers join to form a larger molecule, producing water as a by-product.
Sugar-phosphate backbone
A strong covalently linked chain of five-carbon sugar molecules and phosphate groups in a nucleic acid chain.
Chromosome
A structure made of protein and nucleic acids that carries genetic information.
Gene
A section of DNA that carries the code to make a protein.
Genome
The complete set of DNA housed within an organsim.
Antiparallel
A characteristic of DNA strands describing how each strand runs in an opposite direction to the other.
- The coding strand runs in a 5’ => 3’ direction
- the template strand runs in a 3’ => 5’ direction.
Complementary base pairing
Describes which nucleotides can form hydrogen bonds with each other. C pairs with G, A pairs with T (or U in RNA).
Double helix
The structure of double-stranded DNA in the nucleus of eukaryotic cells, where each DNA strand wraps around a central axis.
Messenger RNA (mRNA)
RNA molecules that are produced during transcription and carry genetic information from the nucleus to the ribosomes.
Transfer RNA (tRNA)
RNA that recognises specific codons on the mRNA strand and adds the corresponding amino acid to the polypeptide chain during protein synthesis.
Ribosomal RNA (rRNA)
RNA that is a key structural component of ribosomes, which assemble proteins.
