rna Flashcards
what is rna
molecule used for translating the genetic code into protein
how do dna and rna differ?
diff. sugar group: Ribose
single strand
Bases: A, C, G and Uracil
what is single strand RNA called
messenger RNA or mRNA
what is looped RNA called
transfer or tRNA
Adenine (A) always bonds with…
Uracil(U)
Guanine (G) always binds with..
Cytosine (C)
what is transcription
the info from DNA is transcribed into a molecule of RNA known as mRNA
where does transcription occur
nucleus
what is translation?
the info from RNA is translated into a protein, with help from tRNA
where does translation occur
ribosome of cytoplasm
first step of transcription
initiation: RNA polymerase unwinds DNA and unzips at the promoter
2nd step of transcription
elongation: mRNA transcript grows and peels away from DNA
-DNA zips itself together as RNA polymerase moves 5’ to 3’
3rd step of transcritption
termination: RNA polymerase releases itself from DNA at the terminator
-new mRNA strand leaves the nucleus through nuclear pores (to build protein)
what does mRNA do in a protein
dictates the order of amino acids
what does tRNA do to amino acids
transports amino acids
what are codons
they read mRNA in increments of 3 nucleotides
what does mRNA dictate
the start and stop of the message
start codon
always the amino acid Methionine
does the stop codon code for an amino acid?
no
first step for protein assembly
mRNA start codon marks beginning
2nd step of protein assembly
tRNA attaches to start codon to find complement
3rd step of protein assembly
anticodon of tRNA matches its mRNA counterpart
4th step of protein assembly
peptide bonds join amino acids (peptide bond formation- dehydration synthesis)
5th step of protein assembly
steps continue until stop codon is reached then new protein emerges
