 Proteins are assembled from amino acids using information encoded in genes . Each protein has its own unique amino acid sequence that is specified by the nucleotide sequence of the gene encoding this protein . The genetic code is a set of three @-@ nucleotide sets called codons and each three @-@ nucleotide combination designates an amino acid , for example AUG ( adenine @-@ uracil @-@ guanine ) is the code for methionine . Because DNA contains four nucleotides , the total number of possible codons is 64 ; hence , there is some redundancy in the genetic code , with some amino acids specified by more than one codon . Genes encoded in DNA are first transcribed into pre @-@ messenger RNA ( mRNA ) by proteins such as RNA polymerase . Most organisms then process the pre @-@ mRNA ( also known as a primary transcript ) using various forms of Post @-@ transcriptional modification to form the mature mRNA , which is then used as a template for protein synthesis by the ribosome . In prokaryotes the mRNA may either be used as soon as it is produced , or be bound by a ribosome after having moved away from the nucleoid . In contrast , eukaryotes make mRNA in the cell nucleus and then translocate it across the nuclear membrane into the cytoplasm , where protein synthesis then takes place . The rate of protein synthesis is higher in prokaryotes than eukaryotes and can reach up to 20 amino acids per second . 
 Proteins are assembled from amino acids using information encoded in genes . Each protein <a href='got' title='1'><mark>has</mark></a> its own unique amino acid sequence <a href='null_relcl' title='2'><mark>that</mark></a>is specified by the nucleotide sequence of the gene encoding this protein . The genetic code is a set of three @-@ nucleotide sets called codons and each three @-@ nucleotide combination <a href='uninflect' title='3'><mark>designates</mark></a> an amino acid , for example AUG ( adenine @-@ uracil @-@ guanine ) is the code for methionine . Because DNA <a href='uninflect' title='4'><mark>contains</mark></a> four nucleotides , the total number of possible codons is 64 ; hence , <a href='dey_it' title='5'><mark>there</mark></a> is some redundancy in the genetic code , with some amino acids specified by more than one codon . Genes encoded in DNA are first transcribed into pre @-@ messenger RNA ( mRNA ) by proteins such as RNA polymerase . Most organisms then process the pre @-@ mRNA ( also known as a primary transcript ) using various forms of Post @-@ transcriptional modification to form the mature mRNA , which is then used as a template for protein synthesis by the ribosome . In prokaryotes the mRNA may either be used as soon as it is produced , or be bound by a ribosome after <a href='been_done' title='6'><mark>having</mark></a> moved away from the nucleoid . In contrast , eukaryotes make mRNA in the cell nucleus and then translocate it across the nuclear membrane into the cytoplasm , where protein synthesis then <a href='uninflect' title='7'><mark>takes</mark></a> place . The rate of protein synthesis <a href='drop_aux' title='8'><mark>is</mark></a>higher in prokaryotes than eukaryotes and can reach up to 20 amino acids per second . 
Proteins r assembled from amino acids usin information encoded in genes . Each protein got its own unique amino acid sequence is specified by the nucleotide sequence of the gene encoding dis protein . The genetic code is a set of three @-@ nucleotide sets called codons and each three @-@ nucleotide combination designate an amino acid , for example AUG ( adenine @-@ uracil @-@ guanine ) is da code for methionine . b/c DNA contain 4 nucleotides , the total number of possible codons is 64 ; hence , it is sum redundancy in the genetic code , wit some amino acids specified by more den one codon . Genes encoded in DNA are first transcribed into pre @-@ messenger RNA ( mRNA ) by proteins such as RNA polymerase . Most organisms then process the pre @-@ mRNA ( also known as a primary transcript ) uusinvarious forms of Post @-@ transcriptional modification to form the mature mRNA , which is then used as a template for protein synthesis by tdaribosome . In prokaryotes the mRNA may either be used as soon as it is produced , or b bound by a ribosome after done moved away from the nucleoid . In contrast , eukaryotes make mRNA in the cell nucleus and then translocate it across thdauclear membrane into the cytoplasm , where protein synthesis then take place . Thedate of protein synthesis higher in prokaryotes than eukaryotes and can reach up to 20 amino acids per second .