Genetic diseases

• Cystic fibrosis

  • A genetic disorder that is caused by a faulty recessive gene which codes for a non-functioning deletion mutation in the CFTR gene on chromosome 7.

  F = normal gene f = defective gene

  Cause: 

  • The CF gene causes the production of a non-functioning protein channel. Consequently, the body produces very sticky mucus that clogs tubes within the respiratory and reproductive organs.

  Symptoms:

  • Mucus in the lungs
  • Affects the respiratory, digestive, and reproductive tract.
  • Can’t produce enough enzymes for digestion.
• Huntington’s disease

  •  a condition that damages nerve cells in the brain causing them to stop working properly.
  • Caused by a dominant gene

  F = faulty gene f = defective gene
• Cell


  The basic unit of all living tissue
• Nucleus


  • Structure found in most human cells
  • Contains the genome
• Genome


  Split between 23 pairs of chromosomes in humans
• Chromosomes


  • Each contains a long strand of DNA
  • Tightly packaged around proteins called histones
• Genes


  Sections within the DNA that contain the instructions for making proteins
• Gene switched on

  1. RNA polymerase enzyme attached to start of gene

  2. Moves along DNA making messenger RNA
• Transcription

  DNA code determines order in which free bases are added to messenger RNA
• Messenger RNA processing


  Removing and adding sections of RNA
• Protein production

  1. Messenger RNA moves to cytoplasm

  2. Ribosomes bind messenger RNA

  3. Ribosomes read code to produce amino acid chain

  4. Transfer RNA carries amino acids to ribosome

  5. Amino acids added to growing chain

  6. Chain folds into 3D protein shape
• There are 20 different types of amino acids
• Messenger RNA is read three bases at a time
• Transcription - DNA - mRNA

  Translate - mRNA - protein 

  DNA - deoxyribonucleic acid

  RNA - ribonucleic acid

  RNA - single

  mRNA - messenger, carry the message (single strand) copies all the information from the DNA

  (AUGC)

  rRNA - ribosomal DNA 

  tRNA - transfer the amino acids
• DNA - ATGC

  RNA - AUGC
• Transcription 

  • copying process of the DNA
• Triplet code

  • 3 letter code, code for protein
  • First 3 letter will code for a single protein
  • How amino acids are made.
• Peptides

  • binds DNA/ amino acids
• Translation

  • The language of DNA and RNA
• DNA to proteins:

  mRNA can come out of the nucleus because it is a single strand. 

  When it comes out of the nucleus and it gets into the cytoplasm, ribosomal RNA comes

  • ribosomes synthesise protein

  Ribosomes will come and attach to the mRNA, it is gonna do its process and will make protein. When it makes protein, the ribosomes will move to the mRNA, and then when they move there, they’ll have amino acids to move. 

  Once the ribosomes get attached to the mRNA, they start reading the nucleotides, the first 3 letters will code for 1 single protein, 20 amino acids 
• How the environment or her lifestyle that could have affected her features:

  • Her diet
  • The amount of exercise she had
  • Diseases she caught/developed
  • Injuries she had
  • Toxins/poisons/chemicals she was exposed to
  • Sunlight/temperature/weather she was exposed to
  • Accidents
• Most of our features are affected by both our genome and our environment.
• Importance of amino acids and genome in making proteins:

  The genome contains genes, and these are the code for making proteins, sequence of bases, always in triplet code. 

  • 1 triplet code will code for amino acids, and amino acids are then joined by polymerisation. Amino acids are the building blocks of protein.