Amino acids & peptide bonds

• What are proteins?


  They're polymers (and macromolecules) made of monomers called amino acids.
• What determines the shape of a protein?


  The sequence, type and number of amino acids.
• What does the shape of a proteins determine?


  It's function
• What do proteins form in cells?


  Enzymes, cell membrane proteins, hormones, immunoproteins, transport proteins, structural proteins and contractile proteins.
• What are amino acids?


  The monomers of proteins.
• How many amino acids are found in proteins common to all living organisms?

  20
• What is the general structure of all amino acids.

  There is a central carbon atom which is bonded to-

  An amine group- NH2 (left)

  A carboxylic acid group- COOH (right)

  A hydrogen atom (bottom)

  An R group (how each amino acid differs) (top)
• What is lost to form a peptide bond from amino acids?

  A hydroxyl (-OH) from the carboxylic group from one amino acid and the other a hydrogen is lost from the amine group.
• What happens to the remaining carbon atom?

  The remaining carbon atom (with the double-bonded oxygen) from the first amino acid bonds to the nitrogen atom of the second amino acid.
• What happens to the carbon atom from the first amino acid during peptide bond formation?

  It bonds to the nitrogen of the second amino acid
• What type of reaction forms a peptide bond?

  It is a condensation reaction
• What is released during the condensation reaction that forms peptide bonds?

  Water
• What are dipeptides formed from?

  Condensation of two amino acids
• How are polypeptides formed?

  By the condensation of many amino acids
• How many amino acids are needed to form a polypeptide?

  Three or more amino acids
• What can a protein consist of in terms of polypeptide chains?

  One or multiple interacting chains
• What occurs during hydrolysis reactions involving peptide bonds?

  Addition of water breaks peptide bonds
• What is the result of hydrolysis of polypeptides?

  They are broken down to amino acids
• What is the process of peptide bond formation?

  A condensation reaction between amino acids
• How does hydrolysis affect polypeptides?

  It breaks them down into amino acids