Biological Molecules - Review Flashcards
Define the primary structure of a protein.
The primary structure of a protein is the sequence of amino acids in a polypeptide chain.
How is the secondary structure of a protein formed?
The secondary structure is formed by hydrogen bonds between the amine (-NH2) and carboxyl (-COOH) groups. This causes the polypeptide to be twisted into a 3D shape (either in alpha-helix or beta-pleated sheet).
What is the function of disulfide linkages in the tertiary structure of proteins?
Disulfide linkages contribute to the stability of the tertiary structure and prevent denaturation of proteins.
What is the role of hydrogen bonds in the tertiary structure of proteins?
Hydrogen bonds are responsible for the solubility of proteins in aqueous solutions.
What is the role of ionic bonds in the tertiary structure of proteins?
Ionic bonds guide the folding of the polypeptide chain meaning the protein acquires its final functional form.
What is the significance of the tertiary structure of proteins?
The tertiary structure of proteins is significant as the 3D shape of each protein is distinctive and allows it to recognise and be recognised by other molecules. The specific shape allows them to interact in a very specific way.
What are proteins which contain more than one polypeptide called?
Proteins which contain more than one polypeptide are called multimeric.
What is the arrangement of polypeptides in multimeric proteins called?
The arrangement of polypeptides in multimeric proteins is called the quaternary structure?
What does antiparallel mean, with regards to DNA strands?
Antiparallel DNA strands run in opposite directions to each other.
In what direction do the two strands run from?
One DNA strand runs 5’ to 3’ whereas the other strand runs 3’ to 5’.
What carbon number, on deoxyribose, is the phosphate group bonded to?
The phosphate group is bonded to carbon 5 on deoxyribose.
What carbon number, on deoxyribose, is the hydroxyl group bonded to?
The hydroxyl group is bonded to carbon 3 on deoxyribose.
Describe how the structure of ATP is useful in biological processes.
ATP:
- releases energy in small amounts,
- is broken down in one step (meaning energy is made available rapidly),
- phosphorylates substances (which makes them more reactive),
- can be reformed.
Describe how the structure of water is useful in biological processes.
Water is:
- a polar molecule (meaning it can act as a universal solvent),
- a universal solvent (metabolic reactions happen faster),
- reactive (it takes place in hydrolysis/condensation reactions),
