Lecture 7 Flashcards
In the free radical mechanism how are bonds broken?
By Homoylsis.
What is homolysis?
Breaking of bonds into 2 equal parts.
Homoylsis is common in what type of bonds?
Non polar bonds.
No charge on atoms.
What is needed for a free radical mechanism?
U/V light- ENERGY
What happens in the initiation step in a free radical mechanism?
Radicals are produced.
What happens in the propagation step in a free radical mechanism?
Radials react with substrate- New radicals are produced so the reactions continues.
What happens in the termination step in a free radical mechanism?
Two radicals combine.
What happens in bond formation between radicals?
Each atom DONATES one electron to form a two- electron bond.
In fatty acid and prostaglandin biosynthesis what is needed to start the reaction?
What is produced? How?
Enzyme.
Radical is produced as hydrogen is removed.
Damage to DNA can cause CANCER. Small amounts of H2O2 in metabolism produce what radicals? Why?
OH radicals because of the weak O2 bond.
What substance prevent radicals from completing a harmful reaction? How?
Antioxidants.
Radical reacts with the antioxidant to form a stable radical so they don’t react with a biological molecule.
What enzyme has been developed to make use of reactivity of radicals?
CP450
In polar/ ionic mechanisms how are bonds broken?
Heteroylsis
In polar/ ionic mechanisms which atom to the electrons move to?
The most electronegative atom.
What is heterolysis?
One species takes both electrons.
