protein synthesis

  • protien

    1. An enzyme attaches to the DNA molecule at the gene of interest.
  • DNA

    1. The two strands of DNA separate at that location.
  • RNA

    1. Complementary RNA nucleotides bond to the nitrogenous bases on one of the separated DNA strands.
  • Nucleotides

    1. The chain of RNA nucleotides forms a single-stranded molecule of RNA by using the DNA strand as a template.
  • codon

    1. When a stop codon is reached, the RNA strand separates from the DNA molecule, leaves the nucleus and goes through the nuclear membrane into the cytoplasm.
  • Strands

    1. The two DNA strands rejoin.
  • GAC

    The mRNA attaches to a ribosome, which contains proteins and ribosomal RNA (rRNA). The function of ribosomes is to assemble proteins according to the genetic message.
    Each three-base nucleotide sequence on the mRNA is called a codon. Each codon specifies a particular amino acid that will be used to build the protein molecule. For example, if the DNA sequence was GAC, then the RNA sequence becomes CUG (transcription) and the amino acid that is coded is Leucine (translation).
  • MRNA

    Another type of RNA, transfer RNA (tRNA), brings amino acids to the ribosome in the order specified by the codon sequence on the mRNA. At one end of each tRNA is the anticodon, a region that consists of three nucleotide bases that are complementary to the codon of mRNA.
  • tRNA

    1. The anticodon of the tRNA, with its attached amino acid, pairs to the codon of the mRNA, which is attached to a ribosome.
  • Amino

    1. When a second tRNA with its specific amino acid pairs to the next codon in sequence, the attached amino acid breaks from the first tRNA and is bonded to the amino acid of the second tRNA.
  • Cytoplasm

    1. The empty tRNA moves off and picks up another matching amino acid from the cytoplasm in the cell.
  • Ribosome

    1. This sequence is repeated until the ribosome reaches a stop codon on the mRNA, which signals the end of protein synthesis.