8c Flashcards
what is the purpose of gene expression?
explaining how cells decode and use the info in their gametes
what are the 2 sequential processes that allow information encoded in genes to be copies as RNA and expressed as proteins?
Transcription and translation
Explain what is meant by the “one gene–one polypeptide hypothesis,”?
suggests that each gene in an organism’s DNA is responsible for encoding a single polypeptide or protein.
One gene - one enzyme (polypeptide) hypothesis was originally proposed by? and later on?
Archibald Garrod in 1901
beadle and Tatum(1941)
central dogma?
states that genetic information flows from DNA to RNA (transcription) and then from RNA to protein (translation)
define transcription
process by which the information encoded in DNA is made into a complementary RNA
define mRNA
The segments of DNA transcribed into RNA molecules that can encode proteins
Define ncRNA
segments of DNA copied into RNA that are not involved in encoding proteins
define translation
process of synthesizing a specific protein by using the info encoded in the mRNA on a ribosome.
_________ are building blocks of proteins?
polypeptides
Most of genes are__________ into mRNA, and then the mRNA is ___________ into polypeptide.
transcribed
translated
where does central dogma occurs in prokaryotes and why?
both transcription and translation occur in the cytoplasm due to the absence of nucleus
where does transcription and translation occurs in eukaryotes?
transcription -nucleus
translation - ribosomes - rough endoplasmic membrane-cytoplasm
define gene
organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately formation of a functional product.
what are the 4 things that a gene is composed of?
promoter
regulatory sequences
transcribed region
terminator
promoter?
site in the DNA where RNA polymerase binds to begin transcription
regulatory proteins
sites binding to regulatory proteins control whether a gene is turned on or off.