biology paper 3

Question 1

formation of urea

Answer 1

deamination
ammonia combines with co2
the ornithine cycle produces urea

Question 2

enzyme increae in temp

Answer 2

enzyme denatures
hydrogen bonds broken
tertiary struture changed/active site
substrate complexes can no longer form

Question 3

process of atherscelrosis

Answer 3

damage to {endothelium} caused by
{high blood pressure / toxins / smoking}
 inflammatory response and arrival of
{macrophages / white blood cells}
 deposits of {cholesterol / calcium}
 formation of {atheroma / plaque}

Question 4

how do vaccines create immunity

Answer 4

antigen presenting cells / MHCs
 APC binds to {T cell /CD4 receptors}
 production of T memory cells
 (activated) T cells
{stimulate B cells / release cytokines}
 production of B memory cells
 plasma cells release antibodies

Question 5

why initial rate of reaction

Answer 5

so substrate conc is not limiting