Proteins Flashcards
What are the monomers from which proteins are made called?
- Amino acids.
How many types of amino acids are there in all organisms?
- 20 amino acids
How is peptide bond formed?
- Peptide bond formed by condensation reaction between two amino acids.
What are dipeptides formed by?
- Dipeptides formed by condensation reaction of two amino acids.
- Peptide bond forms between OH of carboxyl group (on amino acid) and H of the amine group.
What are polypeptides formed by?
- Polypeptides are formed by the condensation of many amino acids.
- Peptide bond forms between OH (of carboxyl group) and H of the amine group.
What is the only part of the amino acid monomer that changes depending on the type of amino acid?
- The R (variable) group.
What are the components of an amino acid monomer, ie. the groups in an amino acid monomer?
- C and H atom in centre
- Amine group (NH₂)
- Carboxyl group (COOH)
- R- group (variable) side chain.
What type of protein contains one or more polypeptides?
- Functional protein may contain one or more polypeptides.
What is a hydrogen bond?
- Chemical bond often between slight negative oxygen atoms and slight positive hydrogen atoms (in water.) (oxygen = slightly negative as it has more electrons than hydrogen.)
() - extra info for clarification
What are the 4 levels of structure in proteins?
1.) Primary
2.) Secondary
3.) Tertiary
4.) Quaternary
Definition of primary structure of protein.
- The sequence of amino acids in a polypeptide chain.
Definition of secondary structure of a protein.
- Sequence of amino acids (ie. primary structure) are bent into alpha helix shapes or folded into beta pleated sheets (this is known as secondary structure.)
- Hydrogen bonds hold the secondary structure of protein.
Where are hydrogen bonds formed in the secondary structure of a protein?
- Hydrogen bonds form between the C=O groups (part of peptide bond of 1 amino acid) and the NH group (in the peptide bond of another amino acid.)
Definition of** tertiary structure** of proteins.
- The further folding of the secondary structure (forms the tertiary structure.)
- Folding forms a unique 3D shape.
- Tertiary structure held in place by ionic, hydrogen and disulphide bonds/ bridges.
What 3 types of bonds hold the tertiary structure of proteins in place?
- Ionic
- Hydrogen
- Disulphide