protein and synthesis

• Proteins are composed of amino acids linked together by peptide bonds
• DNA, or deoxyribonucleic acid, acts as a storage facility of genetic information and carries the code for the expression of inherited characters
• James Watson and Francis Crick were the first scientists who described the DNA molecule as a double helix
• RNA, or ribonucleic acid another type of polynucleotide which codes and decodes genetic information and forms a single helix or twisted shape
• DNA and RNA work together to produce proteins from genetic codes
• Genetic codes in DNA or RNA are made up of nucleotide bases usually in threes (triplets) that code for the amino acids making up the proteins
• The base pairs of DNA are Adenine (A), Cytosine (C), Guanine (G), or Thymine (T)
• The two strands of DNA are held together by hydrogen bonds between pairs of bases: Adenine pairs with Thymine, and Cytosine pairs with Guanine
• RNA is similar to DNA, except that Adenine always pairs with Uracil (A-U)
• Types of RNA:

  • Messenger RNA (mRNA)
  • Ribosomal RNA (rRNA)
  • Transfer RNA (tRNA)
• Transcription is the process where the DNA sequence of a gene is rewritten using RNA nucleotides
• Translation is the second phase of protein synthesis. This involves the complementary pairing of codons in mRNA with anticodons in tRNA, a process that is facilitated by the ribosome
• In Translation, the codes in the messenger RNA are translated to a polypeptide containing a specific series of amino acids
• Initiation, Elongation, and Termination are the stages of Translation
• DNA Replication involves the copying of genetic information from DNA to RNA
• The genetic code is stored in DNA and may be expressed when copied into messenger RNA
• Each triplet code in DNA consists of a particular sequence of nitrogen bases called codons
• Important Codons:

  • Start Codon: AUG (starts the translation stage)
  • Stop Codons: UAG, UGA, UAA (stops the translation stage)
• The ribosome reads the start codon, AUG, to begin the translation stage
• Messenger RNA (mRNA) transcribes the DNA nucleotide bases to RNA nucleotide bases
• Ribosomal RNA (rRNA) binds the mRNA and tRNA to ensure that codons are translated correctly.
• Transfer RNA (tRNA) translates the mRNA codons into the correct amino acids
• the DNA unzips through the help of enzymes called RNA polymerases
• amino acids bond with each other to form polypeptides which make up proteins.