Genetic Code (BIO) Flashcards
DNA -> RNA -> protein
Central Dogma
resides in the nucleus. It codes information in genes.
DNA
Inside the nucleus, the DNA genes get transcribed into RNA (messenger RNAs or mRNAs).
Transcription
The mRNAs get transported out of the nucleus into the cytoplasm. mRNAs are working copies of the gene.
RNA
ribosomes read off the mRNAs to make proteins.
Translation
synthesized by ribosomes. They are the end product of what’s encoded in the genes and they perform all the functions in the cell.
Protein
what are the 2 stages of protein synthesis?
Transcription and translation
a series of 3 bases along a strand of DNA. There are 64 possible sequences of 3 bases in a row, so some amino acids have more than 1 ( ) for them
Triplet code
The mRNA is a sequence of nucleotides, but it codes for a sequence of amino acids. To do this, every 3 nucleotide codes for an amino acid. These triplets of nucleotides are called ( ) A single mRNA contains many ( )
are continuous, non-overlapping and degenerate.
Codons
the 3 bases on the “tip” of the tRNA. A single tRNA contains a single ( ) at the “tip” and the corresponding amino acid at the “tail”. ( ) are complementary to their corresponding codon.
Anti-codon
During translation, codons pair with anticodons so that the correct amino acids can be linked to a given codon.
The codon-anticodon relationship
The genetic code is ( ) because more than one codon can specify a single amino acid.
Degenerate
is an evolutionary development designed to protect against mutations in the coding regions of our DNA.
Wobble
mutated codon that results in a different amino acid.
Missense codon
mutated codon that results in something other than an amino acid. For example, a stop codon.
Nonsense codon
(AUG): signals the start of translation. Lies just downstream of the Shine Dalgarno sequence (Kozak sequence for eukaryotes).
Initiation Codon
(UAG,UGA,UAA): signals the end of translation. Unlike other codons, tRNA are not involved. Instead a protein called “release factor” comes along and terminates translation.
Termination/Stop Codons
messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome
stands for messenger RNA. It’s the product of transcription and the template for translation.
carries the info specifying the amino acid sequence of the protein to the ribosome; transcribed from template DNA by RNA polymerase; only type of RNA that has info that is then translated into a protein
mRNA
occurs when some number of nucleotides are added to or deleted from the mRNA sequence; usually more serious than point mutations
frameshift mutation
