Nucleotides and Nucleic acids Flashcards
(24 cards)
Allele
a version of a gene; also called a gene variant
Degenerate
for all amino acids, excpet methionine and trytothan, there is more than one base triplet available
DNA polymerase
an enzyme that catalyses the formation of DNA from activated deoxyribose nucleotides, using single-stranded DNA as a template
Double helix
the shape of a DNA molecule, due to coiling of the two sugar-phosphate backbone strands into a right-handed spiral configuration
Gene
a length of DNA that codes for a polypeptide or for the length of RNA that is involved in regulating gene expression
genome
the total DNA content of a cell or individual
Gyrase
an enzyme that catalyses the unwinding of the DNA double helix prior to DNA replication
Helicase
an enzyme that catalyses the breaking of hydrogen bonds between the nitrogenous bases in a DNA molecule
Macromolecule
a very large, organic molecule
Monomer
molecule that when repeated makes up a polymer. nulceotides are the monomers of nucleic acids
mutation
a random change in the genetic material of an organism.
gene mutation
a random change in the sequence of bases in DNA
non-overlapping
the genetic code is read from a fixed point in groups of three bases. If a base is added or deleted then it causes a frame shift, as every base triplet after that, and hence every amino acid coded for is changed
nucleotide
molecule consisting of a five-carbon sugar, a phosphate group and a nitrogenous base
polynucleotide
large molecule containing many nucleotides
phosphodiester bond
the bond formed via a condensation reaction in the creation of a nucleotide. It is located between the phosphate group and the deoxyribose or ribose sugar
polypeptide
a polymer made of many amino acid units joined together by peptide bonds. Insulin is a polypeptide of 51 amino acids
protein
a large polypeptide. the terms protein and polypeptide are often used synonymously; however, protein is more commonly used to refer to the final folded project. Insulin may be described as a small protein
RNA polymerase
an enzyme that catalyses the formation of messenger RNA from activated ribose nucleotides, using single stranded DNA as a template
semi-conservative replication
How DNA replicates, resulting in two new molecules, each of which contains one original (old) strand and one new strand. One old strand is conserved in each new molecule
transcription
the process of making messenger RNA from a DNA template
translation
the formation of a protein at ribosomes, by assembling amino acids into a particular sequence according to the coded instructions carried from DNA to the ribosome by mRNA
triplet code
the genetic code is read three bases at a time e.g. three RNA bases on the mRNA (a codon) codes for one specific amino acid
universal
in almost all living organisms the same triplet of DNA bases codes for the same amino acid
