TL2 What are Proteins

TL2 What are Proteins

1. Proteins

   • Big molecules
   • Natural polymers
   • Relative molecular masses up to 100,000
   • Play key role in almost every structure and activity of a living orgaism

2. The Human Genome

   • Gemetic material is stored in chromosomes
   • Each chromosome contrains thousands of genes
   • Genes- contains codons, responsible for making one protein
   • Codons-consists of three bases
   • Human Genome Project
     • completed in 2003
       • goals of project
         • Identify all the genes in human DNA (20,000-25,000
         • Determine sequences of 3 billion chemical base pairs that make up human DNA
         • to store this info in databases
         • improve tools for data analysis
         • transfer related technologies to private sector
         • address ethical, legal and social issues arising from the project

3. Proteins

   • Muscle fibres
     • contain rod-like protein molecules
   • Cell structures
     • Proteins-components of the membranes-form boundires of cells- help hold cells together
   • Structures
     • hair-nails-feathers-made from proteins
   • Binding proteins
     • proteins store+transport important substances-around the body
   • Hormones
     • regulate many processes in the body
   • Enzymes
     • All proteins-highly specific catalysts-control the rates of many reactions in the body

4. Amino acids (the building blocks of proteins)

   • Insulin
     • a hormone-one of the simplest proteins
     • Structure
       • 2 short chains of amino acid residues-joined to form the protein
         • joined by condensation reactions
   • General structure- amino goup (NH2)-carboxylic acid (COOH)- both attached to the same carbon
   • bodies-break down proteins into their constituent 'building blocks'- amino acids
     • bodies cannot synthesise essential amino acids-so gets it from food
       • others made from carbohydrates+other amino acids in the body
   • Order of which amino acids are arranged-makes every protein different
     • called the primary structure