RNA and Protein Synthesis

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RNA and Protein Synthesis
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Genes

• Genes are coded DNA instruction that control the
  production of proteins within the cell
• the first step in decoding the message of DNA is
  copy part of the nucleotide sequence from DNA to
  RNA

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Structure of RNA

• Almost the same as DNA they are long chains of
  nucleotides sugar, phosphate and nitrogen base
• 3 main differences
• Different sugar
• DNA deoxyrobose, RNA ribose
• DNA is a double helix, RNA is a single strand
• RNA has Uracil (U) instead of Thymine (T)

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Types of RNA

• mRNA (messenger) RNA molecule that carries
  copies of instructions from a gene to the
  ribosome
• tRNA (transfer) type of RNA molecule that
  transfers each amino acid to the ribosome
• rRNA (ribosomal) type of RNA that helps make up
  ribosomes

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DNA vs RNA
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Protein Synthesis

• Two main steps
• Transcription
• Takes place in the nucleus
• Translation
• Takes place at the ribosomes

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Transcription

• Transcription is the copying of the information
  from DNA to mRNA
• RNA polymerase is an enzyme that binds to DNA and
  separates the DNA strands. Then it uses one
  strand of DNA as a template to make nucleotides
  of RNA
• The enzyme will only bind to a part of the DNA
  know as a promoter

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Transcription
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The Genetic Code

• Proteins get made by joining together amino acids
  into long chains called polypeptides
• The language that RNA uses to determine the amino
  acid sequence is called the genetic code

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• Every 3 nitrogen bases is called a codon or a
  word
• Each codon is a code for a different amino acid

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Translation

• Translation is when the cell uses the information
  on the RNA to produce proteins

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• mRNA leaves the nucleus and attaches to a
  ribosome
• tRNA will bring amino acids to the ribosome
• Anticodons on the tRNA will attach to the codon
  of mRNA linking the amino acids together in the
  correct order

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