D3

Question 1

What is detoxification

Answer 1

The removal of toxins/drugs which are usually fat soluble, converting them into less harmful water-soluble forms

Question 2

What are the 2 mechanisms of detoxification?

Answer 2

CONVERSION OF TOXINS
into less harmful chemicals by oxidation, reduction and hydrolysis reactions
–> mediated by a group of enzymes: cytochrome P450
produce damaging free radicals, which are neutralized by antioxidants within the liver

ATTACHMENT TO ANOTHER SUBSTANCE
via conjugation reaction
–> makes it less harmful and water-soluble + can be excreted from the body (urine/feces)

Question 3

Explain how components of RBC are recycled

Answer 3

RBC have no organelles and no nucleus (to carry more hemoglobin) and have short lifespan (120 days).
Liver breaks down RBC and recycles components, used to make either new RBCs or other important compounds (e.g. bile)

Question 4

Explain the role of Kupffer cells

Answer 4

• Specialised phagocytes within the liver
• Engulf RBC to break them down
• Break down hemoglobin into heme (group containing iron) and globin (protein)

Question 5

What happens to globin and heme after being broken by Kupffer cells ?

Answer 5

Globin: digested by peptidases to produce amino acids (either recycled or metabolized by the liver)

Heme: broken down into iron and bilirubin (bile pigment)

Question 6

Explain the path of iron

Answer 6

Must be complexed within a protein to avoid oxidation to a ferric state
–> stored by liver within a protein shell of ferritin
–> transported to bone marrow (where new hemoglobin is produced) within transferrin protein