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Intro to Amino Acids quiz

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  • What are the three main groups attached to the alpha carbon in an amino acid?
    The alpha carbon is attached to an amino group, a carboxyl group, and a variable R side chain.
  • What is the significance of the alpha carbon in amino acids?
    The alpha carbon is central and connects the amino group, carboxyl group, hydrogen atom, and R group.
  • At physiological pH, what form do amino acids primarily exist in?
    They exist in the zwitterion form, with both a positive and a negative charge.
  • What charge does the amino group carry at physiological pH?
    The amino group is protonated and carries a positive charge (NH3+).
  • What happens to the carboxyl group of an amino acid at physiological pH?
    The carboxyl group loses a proton and becomes a negatively charged carboxylate anion (COO-).
  • What is a zwitterion?
    A zwitterion is a molecule with both positive and negative charges on different groups.
  • How many standard alpha amino acids are there?
    There are 20 standard alpha amino acids.
  • What distinguishes one amino acid from another?
    The type of R group attached to the alpha carbon distinguishes each amino acid.
  • What is the role of amino acids in living organisms?
    Amino acids are the building blocks of proteins in living organisms.
  • What does the R group in an amino acid represent?
    The R group is a variable side chain that can be a hydrogen, carbon, or a more complex group.
  • How many different R groups are found in standard amino acids?
    There are 20 different R groups, one for each standard amino acid.
  • What is the generic structure of an alpha amino acid?
    It consists of an alpha carbon attached to an amino group, carboxyl group, hydrogen atom, and an R group.
  • Why does the amino group become positively charged at physiological pH?
    It gains a proton (H+), resulting in a positively charged NH3+ group.
  • Why does the carboxyl group become negatively charged at physiological pH?
    It loses a proton (H+), forming a carboxylate anion (COO-).
  • What is the pH value considered physiological for amino acids?
    Physiological pH is approximately 7.4.