Lesson 13 And 14 Flashcards
Nucleotides
A building block of nucleic acids, consisting of a five carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups
Polynucleotide
A polymer made up of many nucleotide monomers covalently bonded together
Sugar phosphate backbone
In a polynucleotide (DNA or RNA strand) the alternating chain of sugar and phosphate to which nitrogenous bases are attached
deoxyribonucleic
(DNA) A double stranded helical nucleic acid molecule consisting of nucleotide monomers with deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T). Capable of replicating DNA is an organism’s genetic material.
Thymine (T)
A single-ring nitrogenous base found in DNA
Cytosine (C)
A single ring nitrogenous base found in DNA and RNA
Guanine (G)
A double ring nitrogenous base found in DNA and RNA
Adenine (A)
A double ring nitrogenous base found in DNA and RNA
Uracil (U)
A single ring nitrogenous base found in RNA
Double helix
Form of native DNA, referring to its two adjacent polynucleotide strands interwound into a spiral shape.
Semiconservative model
Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and newly made strand.
DNA Polymerase
A large molecular complex that assembles DNA nucleotides into polynucleotides using a preexisting strand of DNA as a template.
DNA ligase
An enzyme, essentially for DNA replication, that catalyzes the covalent bonding of adjacent DNA polynucleotide strands. DNA ligase is used in genetic engineering to paste a specific piece of DNA containing a gene of interest into a bacterial plasmid or other vector.
Transcription
The synthesis of RNA on a DNA template
Translation
The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of “language” from nucleotides to amino acids.
Triplet code
A set of three-nucleotide-long “words” that specify the amino acids for polypeptide chains.
Codon
A three-nucleotide sequence in mRNA that specifies a particular amino acid or polypeptide termination signal; the basic unit of the genetic code.
Genetic code
The set of rules that dictates the amino acid translation of each mRNA nucleotide triplet.
RNA Polymerase
A large molecular complex that links together the growing chain of RNA nucleotides during transcription, using a DNA strand as a template.
Promoter
A specific nucleotide sequence in DNA located near the start of a gene that is the binding site for RNA polymerase and the place where transcription begins.
Terminator
A special sequence of nucleotides in DNA that marks the end of a gene. It signals RNA polymerase to release the newly made RNA molecule and then to depart from the gene
Messenger RNA (mRNA)
The type of ribonucleic acid that encodes genetic information from DNA and conveys it to ribosomes where the information is translated into amino acid sequences.
Intron
An internal, non coding region of a gene that does not become part of the final messenger RNA molecule and is therefore not expressed
RNA splicing
The removal of introns and joining of exons in eukaryotic RNA, forming an mRNA molecule with a continuous coding sequence; occurs before mRNA leaves the nucleus.
Transfer RNA (tRNA)
A type of ribonucleic acid that functions as an interpreter in translation. Each tRNA molecule has a specific anticodon, picks up a specific amino acid, and conveys the amino acid to the appropriate codon on mRNA.
Anticodon
On a tRNA molecule, a specific sequence of three nucleotides that is complementary to a codon triplet on mRNA.
Ribosome
A cell structure consisting of RNA and Protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. In eukaryotic cells, the ribosomal subunits are constructed in the nucleolus.
Ribosomal RNA (rRNA)
The type of ribonucleic acid that, together with proteins, make up ribosomes; the most abundant type of RNA in most cells.
Start codon
On mRNA the specific three-nucleotide sequence (AUG) to which an initiator tRNA molecule binds, starting translation of genetic information
P site
One of a ribosomes binding sites for the tRNA during translation. The P site holds the tRNA carrying the growing polypeptide chain. (P stands for peptide tRNA)
A site
One of a ribosomes binding sites for tRNA during translation. The A site holds the tRNA that carries the next amino acid in the polypeptide chain. (A stands for aminoacyl tRNA)
Stop codon
In MRNA, one of three triplets (UAG, UAA< UGA) that signal gene translation to stop.
