dna

• what are genetic mutations

  alterations in the genetic material of an organisms
• the two types of mutations?

  hereditary - passed from parent to child
• what is hereditary

  it is passed from parent to child
• what is acquired

  it occurs at some point during a person's life
• when do hereditary mutations occur

  happens in the gametes (eggs or sperm) of a parent and can be passed onto their offspring
• where are these mutations present - hereditary

  are present throughout a person's life in virtually every cell in the body
• what hereditary mutations responsible for

  cystic fibrosis or haemophilia
• when do acquired mutations happen - somatic mutations-

  happen at some point during a person's life - only present in certain cells
• how are these changes caused - acquired are caused by

  
  

  environmental factors such as uv radiation from the sun - can occur if a mistake is made when dna is copied during cell division
• are acquired mutations passed do

  • cannot be passed onto the next generation but can lead to conditions but can lead to conditions like cancer
• what are the effects of mutation

  mutations can alter an organism's dna and can lead to changes in health or physical characteristic

  • depends on the specific alteration and the environment
• what are the two types of genetic mutation methods

  • genome sequencing
  • genetic testing
• what is translation

  • involves converting the formation in mRNA into a sequence of amino acids to produce proteins
• where does translation occur

  • in the ribosomes of the cell, located in the cytoplasm
• what happens in stage 1 - initiation

  the ribosome attaches to the start codon (AUG) on an mRNA molecule

  • a transfer RNA molecule that complements the start, carrying a specific amino acid binds to the mRNA
• what happens in stage 2 - elongation

  a second tRNA molecule, carrying a different amino acid and a complementary anti codon to the next codon on the mRNA, attaches to the adjacent binding site

  the ribosome aids the formation of a peptide bond between the two amino acids detaching the first tRNA

  the ribosome moves along the mRNA repeating this process until it reaches a stop codon
• what happens in stage 3 - termination

  once a stop codon is reached, the process of translation ends

  the polypeptide chain formed during translation folds into a protein

  the mRNA and the last tRNA molecule detach from the ribosome
• post-translation modification

  the newly formed polypeptide chain undergoes various modifications to become a functional protein

  certain amino acids might be chemically modified, extraneous sequences might be removed and the protein might be folded into ts required shape

  some proteins also have carbohydrates added or are sent to the golgi apparatus for further modifications