1.3 proteins Flashcards
what are the monomers for proteins?
amino acids
how many different amino acids are there?
20
what bonds are amino acids joined by?
peptide bonds formed in condensation reactions
what are the four types of structure of a protein?
-primary
-secondary
-tertiary
-quaternary
what is the primary structure of a protein?
the sequence of amino acids that make up the polypeptide chain held together by peptide bonds
what is the secondary structure of a protein?
the arrangement of the polypeptide chain into a regular, repeating structure, held together by hydrogen bonds
(a-helix or b-pleated sheet)
what is the tertiary structure of a protein?
-the 3D folding of the tertiary structure
- hydrogen bonds, disulphide bonds and ionic bonds between amino acids hold these 3D shapes
(globular proteins and fibrous proteins)
what is the quaternary structure of a protein?
-3D arrangement of more than one tertiary polypeptide
(enzymes and haemoglobin)
what can affect the structure of proteins?
-temperature
-pH
what are the three types of bonds between R groups in an amino acid?
hydrogen bonds
disulphide bonds
ionic bonds
where do hydrogen bonds form and what are their purpose?
-between carboxyll groups and hydrogen atoms
-weak but very important in the folding of the polypeptide chain
where do disulphide bonds form and what is their purpose?
-form during oxidation between two sulfur containing groups resulting in a strong covalent bond
-important for holding the polypeptide chains in place
where do ionic bonds form and what is their purpose?
-form between strongly positive and strongly negative amino acid side chains
-strong but not very common
how does straigtening your hair change the bonds in your hair?
becuase hair is made out of protein, it breaks the hydrogen bonds and reforms them in the way you style it and it holds temporarily until the bonds reform
what are the two types of proteins?
-fibrous
-globular
