a sequence of 3 DNA nucleotides that stands for 1 amino acid is a base triplet

A sequence of 3 dna nucleotides that stands for 1

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a sequence of 3 DNA nucleotides that stands for 1 amino acid is a basetripleta 3-base sequence in mRNA is called a codonstop codonssignal the “end of the message” & enable the cell’sprotein-synthesizing machinery to sense that it has reached the end ofinstruction for a particular protein; these include: UAG, UGA, and UAAthe codon AUG plays two roles:it serves as a code for methionine it serves as a start codonProtein Synthesis (book)DNA & RNA collaborate together to produce proteins genetic code in DNA specifies which protein a cell can make all body cells except the sex cells & some immune cells containidentical genes; however, different genes are activated in differentcells (example: genes for digestive enzymes are active in stomach cellsbut not muscle cells)
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any given cell only uses one-third to two-thirds of its genes; restremain dormant in that cell, but may be functional in other types ofcellswhen gene is active, messenger RNA (mRNA) is made – a mirror imageof the genemRNA migrates from the nucleus to cytoplasm where it serves as acode for assembling amino acids in the right order to make a particularprotein think of the process as DNA  mRNA  protein (each arrow reading as“codes for the production of) the step from DNA to mRNA is transcriptionoccurs in the nucleusthe step from mRNA to a protein is translationoccurs in the cytoplasmTranscription DNA is to large to leave the nucleus & participate directly incytoplasmic protein synthesis, so it is necessary to therefore make asmall mRNA copy that can migrate through a nuclear pore into thecytoplasmjust as we may transcribe (copy) a document, transcription, means theprocess of copying genetic instructions from DNA to RNAan enzyme called RNA polymerase binds to the DNA & assembles theRNA RNA polymerase opens up the DNA helix, reading the bases from onestrand of the DNA & making a corresponding RNA; then rewinds theDNA helix behind itthe RNA produced by transcription is an “immature” form called pre-mRNAcontaining “sense” portions called intronsthat must be removedbefore translation enzymes remove & degrade introns & splice the exons together into afunctional mRNA molecule, which then leaves the nucleusintrons are removed while still inthe nucleus & the exons beingexported from the nucleus to undergo translation in thecytoplasmthrough a mechanism called alternate splicing, 1 gene can code formore than 1 protein Translationjust as we might translate Spanish into English, genetic translationconverts the language of nucleotides into the language of amino acidsthis job is carried out by the following participants:messenger RNA (mRNA): carries the genetic code from the nucleus tothe cytoplasm
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during its synthesis in the nucleus, mRNA acquires a protein capthat acts like a passport, permitting it to pass through a nuclear
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