3.1.4.1-Proteins Flashcards
(18 cards)
Describe how amino acids are joined together to form a dipeptide
Condensation reaction
Water is removed
Peptide bond formed between carboxyl group and amine group
What are proteins?
Polymers made up of the monomers amino acids
Primary structure of a protein
The sequence of amino acids in the polypeptide chain joined by peptide bonds
Secondary structure of a protein
Polypeptide chain twisted into alpha-helix or beta pleated sheets
Hydrogen bonds beween C=O and the N-H groups
Tertiary protein structure
Secondary structure of protein further folded
To form unique 3D shape
Held by ionic,hydrogen and disulphide bonds
Quaternary structure of a protein
Protein made up of more than one polypeptide chain
Where are the bonds formed in the tertiary structure?
Between the R groups of the amino acids
How are polypeptides formed?
The condensation of many amino acids
Why is a primary structure important?
Different sequence of amino acids (different primary structure)
Forms ionic/hydrogen/disulphide bonds in different places
Resulting in different 3D shape
How do we test for proteins?
Biuret
Blue—>purple
Describe how monomers join to form the primary structure of a protein
Monomers join through condensation reaction
Forming peptide bonds
Creating specific sequence of amino acids
Describe how a peptide bond is formed between two amino acids to form a dipeptide
Condensation reaction between amine and carboxyl
The secondary structure of a polypeptide is produced by bonds between amino acids.Describe how
Hydrogen bonds between NH and C=O
Two proteins have the same number and type of amino acids but different tertiary structures.Explain why
Different sequence of amino acids forms ionic/hydrogen/disulfide bonds in different places
A dipeptide consists of two amino acids joined by a peptide bond.Dipeptides may differ in the type of amino acids they contain.Describe 2 ways which all dipeptides are similar and one way they might differ.
Similarities-Amine group
Carboxyl
Difference-Different R groups
Describe the structure of proteins
-Polymer of amino acids
-joined by glycosidic bonds
-formed by condensation reaction
-Primary structure is a sequence of amino acids
-Quaternary structure is multiple polypeptide chain
Describe how the structure of protein depends on the amino acids it contains
Structures determined by position of amino acids
Primary structure is sequence amino acids
Secondary structure formed by hydrogen bonding
Structure formed by interactions between R groups
Create active site in enzymes
Quaternary structure contains more than one polypeptide chain
Describe the role of a ribosome in the production of a polypeptide. Do not include transcription
MRNA binds to ribosome
Allows tRNA with anticodons to bind
Catalyses formation of peptide bond between amino acids
