Biochem

Question 1

What does endonuclease do? what happens if its defective?

Answer 1

Helps in nucleotide excision repair. If DNA is damaged, endonucleases are supposed to recognize the damage and take these pieces out.
If defective - this is called Xeroderma pigmentosum. These ppl have photosenstitivity and inc risk for skin cancer.

Question 2

What happens in an aldolase B deficiency?

Answer 2

This is called Hereditary Fructose Intolerance
Fructose-1-P builds up and uses up the phosphate via fructose kinase.
Babies will have jaundice, cirrhosis, nausea, vomiting, hypoglycemia

Question 3

Galactokinase deficiency

Answer 3

no galactokinase, results in Galactose –> Galacitol
Galactose in blood, urine, infantile cataracts, failure to track objects and develop a smile
this is the “KINDer” one in comparison to classic galactosemia

Question 4

Classic Galactosemia

Answer 4

Absence of GIP Uridyltransferase
You are able to still use Galactokinase therefore phosphate is being used to make G-1-P.
All the phosphate is being used but you are not making any energy therefore this is BAD.
Symptoms: infantile cataracts, intellectual disability, jaundice, failure to thrive, can predispose E.Coli sepsis in neonates

Question 5

what happens in peroxisome

Answer 5

oxidation of very long and branched fatty acids

hydrogen peroxide degradation