dna transcription - keywords & types of rna

what is dna transcription?

process in which one strand of DNA is used as a template for the synthesis of a complentary RNA strand by RNA polymerase

what is a gene

a unit of DNA that contains information for the synthesis of a polypeptide or RNA

what is the template strand?

strand of DNA which is used to build RNA molecule

it determines the order in which ribonucleoside triphosphate (rNTP) monomers are joined together

what is mRNA (messenger RNA)

any RNA that specifies the order of amino acids in a protein (determines the primary structure)

product of DNA transcription

what is RNA polymerase

enzyme that synthesises RNA molecules

what is a promoter region?

sequence of DNA that determines site of transcription initiation

what is a transcription factor?

protein that is required to initiate/regulate transcription in eukaryotic cells

what is a transcription unit?

region in DNA that is bounded by an initiation and termination site that is transcribed

what does upstream mean?

region of DNA before the initiation site

marked by negative numbers

what does downstream mean?

region of DNA after initiation site, direction in which a template DNA strand is transcribed

marked by positive numbers

what is the most common type of RNA in an E.coli cell?

rRNA (ribosomal RNA) 83%

tRNA (14%)

mRNA (3%)

what is ribosomal RNA (rRNA)?

RNA molecules that are structural/functional components of ribosomes

what is transfer RNA (tRNA)?

group of small RNA molecules that carry amino acids to ribosome during protein synthesis

what is messenger RNA (mRNA)?

RNA transcribed from DNA template strand

is used in protein synthesis to determine order of amino acids in polypeptide

what makes RNA?

all types of RNA are made by RNA polymerases (but different types of polymerases)

RNA pol I = rRNA

RNA pol II = mRNA

RNA pol III = tRNA