Pentose Phosphte Pathway

Question 1

What is its purpose (three)

Answer 1

To generate NADPH for removal of reactive oxygen species, to provide NADPH for biosynthetic purposes, and to provide ribose-5-phosphate for nucleotide biosynthesis

Question 2

How are ROS harmful

Answer 2

Lipid peroxidation, causing membrane leakage, hence swelling. Opening of mitochondria permeability transition pore, causing cell death, as it is only activated during apoptosis. Also, modification of DNA, preventing it from being copied.

Question 3

How aging relates to mitochondria

Answer 3

Ageing is caused by slow deterioration of mitochondrial function in all cells. This is caused by oxygen radicals and mistakes during mitochondrial DNA replication. This causes miss-assembly or malfunction of mitochondrial respiratory chain complexes.

Question 4

Enzymes that provide defense against oxygen radicals

Answer 4

Catalase, superoxide dismutase, glutathione peroxidase

Question 5

Use of oxygen radicals

Answer 5

Used by neutrophils to take out bacteria and used as a vascodilator for erections

Question 6

How parkinson’s disease is related to oxygen radicals

Answer 6

Less dopamine is created when oxygen radicals cause lipid peroxidation, protein oxidation and DNA strand breaks. These symptoms result in neuronal degradation, resulting in reduced dopamine release.

Question 7

How cardiovascular disease is related to oxygen radicals

Answer 7

LDLs get affected, causing them to take up lots of cholesterol and settle down, blocking blood vessels.

Question 8

Which vitamin helps prevent coronary heart disease from oxygen radicals, and why?

Answer 8

Vitamin E has a similar function to ubiquinone. It quenches radicals and lives in the membranes of LDLs and other membranes.