7.1 Gene to Protein Flashcards
Beadle and Tatum
- used orange bread mould to show relationship b/t gene and enzyme
- neurospora grows on MM of growth and reproduction
- exposed spores to x-rays that caused random mutations but some did not grow unless additional nutrients were added
one gene-one enzyme hypothesis
proposed by beadle and Tatum that each gene is unique and codes for synthesis of single enzyme
one gene-one polypeptide hypothesis
each gene is unique and codes for synthesis of one gene-one enzyme hypothesis
central dogma
genetic info flows from DNA to RNA to proteins
transcription
info coded in nucleic acids of DNA copied into nucleic acids of RNA
translation
info coded in nucleic acids of RNA copied into amnio acids of protein
ribonucleic acid?
- contains ribose sugar
- no thymine - RNA contains uracil paired w adenine in DNA strand
- single stranded
mRNA
end product of transcription of gene; translated by ribosomes into protein
- acts as intermediary b/t DNA and ribosomes
tRNA
carrier molecule that binds to specific amino acid and adds amino acid to polypeptide chain
- transfers appropriate amino acid to ribosome to build protein
rRNA
RNA molecule within ribosome that binds correct amino acid to polypeptide chain
- structural component of ribosome and varies in length
RNA polymerase
reads DNA and creates complementary strand of RNA
template strand
DNA strand copied into mRNA molecule during transcription
pre-mRNA
initial RNA product
In translation?
mRNA molecule associates w ribosome, as ribosome moves along, mRNA delivered by tRNA to ribosome
-amino acids join to form polypeptide
genetic code
specific coding relationship b/t bases and amino acids they specify; can be expressed in terms of DNA or RNA
- RNA alphabet (A U C G)
- DNA alphabet (A T C G)
codon
group of 3 base pairs that code of individual amino acid
start codon
codon that signals start of polypeptide chain and initiates translation
stop codon
signals end of polypeptide chain and causes ribosome to stop translation
