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Genetics Molecular

Genetics Molecular. A REVIEW. What does DNA do?. DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. What does DNA do?.

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Genetics Molecular

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  1. Genetics Molecular A REVIEW Rosa Macaya IES La Pobla de Segur

  2. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. Rosa Macaya IES La Pobla de Segur

  3. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. • A gene codes for A protein. Rosa Macaya IES La Pobla de Segur

  4. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. • 1 gene codes for 1 protein. • How does DNA determine the sequence of a.a.s? Rosa Macaya IES La Pobla de Segur

  5. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. • 1 gene codes for 1 protein. • How does DNA determine the sequence of a.a.s? • A group of three bases coding for an amino acid is called a codon, and the meaning of each of the 64 codons is called the genetic code Rosa Macaya IES La Pobla de Segur

  6. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. • 1 gene codes for 1 protein. • How does DNA determine the sequence of a.a.s? • A group of three bases coding for an amino acid is called a codon, and the meaning of each of the 64 codons is called the genetic code Rosa Macaya IES La Pobla de Segur

  7. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. • 1 gene codes for 1 protein. • How does DNA determine the sequence of a.a.s? • A group of three bases coding for an amino acid is called a codon, and the meaning of each of the 64 codons is called the genetic code • DNA is in the nucleus Rosa Macaya IES La Pobla de Segur

  8. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. • 1 gene codes for 1 protein. • How does DNA determine the sequence of a.a.s? • A group of three bases coding for an amino acid is called a codon, and the meaning of each of the 64 codons is called the genetic code • DNA is in the nucleus Rosa Macaya IES La Pobla de Segur

  9. What does DNA do? • DNA is made up of genes. A gene is a sequence of DNA which codes for the sequence of amino acids in a particular protein. • 1 gene codes for 1 protein. • How does DNA determine the sequence of a.a.s? • A group of three bases coding for an amino acid is called a codon, and the meaning of each of the 64 codons is called the genetic code • DNA is in the nucleus • Proteins are made in the cytoplasm  the information contained within DNA must be carried to the cytoplasm. • This process is called TRANSCRIPTION. Rosa Macaya IES La Pobla de Segur

  10. Template strand RNA pol Start of gene Transcription DNA unwinds & unzips at the start of a particular gene. H bonds break • mRNA chain drops off the DNA DNA re-winds. This continues until the end of the gene. • Free activated mRNA nucleotides in the nucleus complementary base pair with exposed DNA bases. (A – U, T – A, C – G, G – C) RNA polymerase joins the mRNA nucleotides together, releasing the phosphoryl groups for energy. Rosa Macaya IES La Pobla de Segur mRNA exits nucleus via a nuclear pore. Carrying the information/ message

  11. The Genetic Code The codon (a triplet) AAU would code for…….. There are 20 essential amino acids The genetic code is a TRIPLET CODE 3 bases code for 1 amino acid Only 4 bases If each coded 1 a.a only 4 different types. How many if a pair coded for 1 a.a? 16 Still inadequate What about if 3 coded for 1 a.a? 64 Yeah! Rosa Macaya IES La Pobla de Segur

  12. A C C ATP A bit more about tRNA Anti-codon VAL Amino-acid attachment site Amino-acid Amino acids must combine with the tRNA molecule. The tRNA molecule is then said to be ACTIVATED This is then called AMINO-ACYL tRNA This is catalysed by amino-acyl tRNA synthetase Rosa Macaya IES La Pobla de Segur

  13. VAL MET ILE VAL GLN GLN GLN MET MET MET A A A A U U U U G G G G translatión GLN A peptide bond is formed between the 2 amino acids on top of the 1st and 2nd tRNA molecules. Ribosome reads the 2nd codon. Another tRNA molecule with the complementary anti-codon binds to this 2nd codon. Another tRNA molecule with the complementary anti-codon binds to the 3rd codon. These steps are repeated until the ribosome reads a STOP codon. (ELONGATION the TERMINATION) A peptide bond is formed between the 2 amino acids on top of the 2nd and 3rd tRNA molecules. The ribosome moves along the mRNA to the 3rd codon. This releases the 1st tRNA molecule but not the a.a. mRNA enters the cytoplasm & joins to the small subunit of a ribosome tRNA with a complementary anticodon (UAC) base pairs with the start codon Ribosome reads along until a start codon (AUG) is found The 2nd tRNA molecule is released. 2 codons (6 bases) are exposed Rosa Macaya IES La Pobla de Segur

  14. Base deletion Where 1+ base pairs are deleted Types of Mutation: Intended txt: Actual txt: A FRIEND WILL COLLECT MY MONEY A FIEND WILL COLLECT MY MONEY • Normal: UCA CAU UAC UGU GGU Consider this…. • Mutated: UCA CAU UAU GUG GU Rosa Macaya IES La Pobla de Segur

  15. Haemophilia Sufferers: Phenylketonuria (PKU) • Phenylalanine hydroxylase catalyses the reaction: • Lack of a blood clotting protein • (Mutation in the factor (protein) blood clotting factor gene) Phenylalanine → tyrosine (→ melanin) • (brown pigment) • PKU is caused by a gene mutation Rosa Macaya IES La Pobla de Segur

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