Lecture 01

Cards (37)

  • What do proteins carry out in a cell?
    Most activities of the cell
  • How many different proteins can a typical human cell have?
    Up to 10,000 different proteins
  • What is the role of structural proteins?
    Provide mechanical support
  • Name two intracellular structural proteins.
    Tubulin and actin
  • Name two extracellular structural proteins.
    Keratin and collagen
  • What do transcription factors do?
    Switch genes on and off
  • What is the function of enzymes?
    Accelerate the rate of metabolic reactions
  • How many enzymes are the main source of energy for cells?
    8 enzymes
  • What do membrane transporters do?
    Determine what substances enter and leave the cell
  • What role do receptors play in cells?
    Participate in signaling
  • What is the role of antibodies?
    Involved in immune response
  • What do motor proteins do?
    Transport cellular cargo
  • What is kinesin's role?
    Moves along a microtubule
  • What is myosin's function?
    Generates muscular contraction
  • What are the key functions of proteins?
    • Structure
    • Regulation
    • Transport
    • Catalysis
    • Signalling
    • Immune defence
  • How are proteins formed from genes?
    mRNA is translated according to genetic code
  • What is the structure of an amino acid?
    Contains alpha chiral carbon
  • What do side chains of amino acids determine?
    Properties of the amino acids
  • What are polar side chains?
    Hydrophilic side chains
  • What are apolar side chains?
    Hydrophobic side chains
  • What affects the distribution of polar and hydrophobic amino acids?
    Protein environment
  • What happens to acidic amino acids?
    Lose H+ and gain negative charge
  • What happens to basic amino acids?
    Can accept H+ and gain positive charge
  • What do polar uncharged amino acids do?
    Form hydrogen bonds
  • What is unique about cysteine residues?
    Form disulfide bonds with other cysteines
  • What are derived amino acids?
    Formed by post-translational modifications
  • How are amino acids linked together?
    By peptide bonds
  • How many amino acids do proteins contain?
    50 or more amino acids
  • What is the longest polypeptide?
    Titin with 27,000 amino acids
  • What is the characteristic of peptide bonds?
    Have partial double bond character
  • What is the configuration of almost all peptide bonds?
    Trans configuration
  • Which amino acid has similar energies in cis and trans configurations?
    Proline
  • What are the groups linked to the Cα atom in amino acids?
    • Amine group
    • Carboxyl group
    • H atom
    • Side chain (R group)
  • What types of side chains can amino acids have?
    • Hydrophobic
    • Polar uncharged
    • Polar charged
  • Which amino acids are often found on the surface of cytosolic proteins?
    Lysine
  • Which amino acids are found in the core of cytosolic proteins?
    Leucine
  • The peptide bond between the first and second residue in the protein is between which atoms?
    C from res. 1 and N from res. 2