314.1 Proteins Flashcards
What are the monomers of proteins
Amino acids
List out the elements that make up proteins.
Carbon, Hydrogen, Oxygen, Nitrogen, Sulphur
Describe the structure of an Amino Acid.
H2N (Amino group) on the left, COOH (Carboxyl group) on the right, R (variable group) on the bottom.
What type of reaction causes two amino acids to bond together, and what bond holds two amino acids together?
Condensation reaction
Peptide bond
What is a functional protein?
A protein that has a particular role, which is not involved in structure.
What is the primary structure of a protein?
Amino acid sequence, joined by peptide bonds.
What is the secondary structure of a protein?
Alpha helix and Beta-pleated sheets, created by Hydrogen bonding.
What kind of bonds are secondary structure limited to?
Hydrogen bonds
What is Alpha helix and Beta-pleated sheets?
A-helix: coiling of the polypeptide chain
B-pleated sheet: folding of the polypeptide chain
What is the tertiary structure of a protein?
Folding of the polypeptide chain into a 3D shape held together by ionic bonds, hydrogen bonds, disulphide bonds.
What is the quaternary structure of a protein?
Multiple polypeptide chains joined together, possibly with a prosthetic group attached.
What is a prosthetic group?
Non-protein component in a protein (E.G. iron containing haem group in haemoglobin.)
Describe the test for proteins (biuret reagent test)
Add equal volumes of the sample and biuret reagent and mix gently. If protein is present then a colour change from blue to purple.
What are the two main types of proteins?
Globular and fibrous
What are the main role of fibrous proteins? What makes it stable?
Structural
- Main parallel chains bonded with cross bridges
