DNA Transcription Flashcards
(49 cards)
Who proposed the concept of inborn errors of metabolism?
Archibald Garrod.
What disorder did Garrod study?
Alkaptonuria (the black urine disease)
What organism did Beadle and Tatum use in their experiment?
Bread mold, Neurospora crassa
What was the key finding of Beadle and Tatum?
Each gene is responsible for producing one enzyme.
What was the original hypothesis called?
“One gene–one enzyme.”
How was this hypothesis later modified?
It became “one gene–one polypeptide” or one gene-one protein”
How did Beadle and Tatum induce mutations?
With X-rays.
How did they identify mutated strains?
By observing mold that could not grow on minimal medium without added nutrients.
What did these findings imply
about inheritance?
Genes influence traits by encoding proteins.
Why was this a turning point in genetics?
It connected genotype (genes) to phenotype (traits) through proteins
What is the central dogma of molecular biology?
DNA is transcribed into RNA, which is translated into proteins.
What is transcription?
The process of copying DNA into RNA.
What is the purpose of mRNA?
It carries genetic instructions from DNA to the ribosome.
What is translation?
The process of assembling a polypeptide using the mRNA template.
Where does translation occur?
In the cytoplasm, on ribosomes.
What are retroviruses?
Viruses that use RNA as genetic material and reverse transcribe
it into DNA.
What enzyme do retroviruses use?
Reverse transcriptase.
Name a retrovirus.
HIV.
How do retroviruses challenge the central dogma?
They reverse the typical flow by converting RNA to DNA.
Where does transcription occur in prokaryotes?
In the cytoplasm.
Where does transcription occur in eukaryotes?
In the nucleus.
What enzyme transcribes DNA in prokaryotes?
RNA polymerase (one type).
How many RNA polymerases do eukaryotes have?
Three (I, II, III).
