Some people have a condition called diabetes. In type 1 diabetes the pancreas does not produce enough insulin. Fig. 7.1 shows the blood glucose concentrations of a type 1 diabetic person and a non-diabetic person, at regular intervals after drinking a glucose drink. [Figure 7.1] A reading of the concentration of glucose in the urine can be estimated using a dipstick. Fig. 7.2 outlines how a dipstick works. [Figure 7.2]

Mark scheme

Marking points from the official mark scheme (May/June 2019). The mark or mark type is shown in brackets.

1. [3] any three from: 1 blood glucose concentration rises in both with drink ; 2 diabetic, always / initially, has higher blood glucose concentration ; 3 diabetic has, higher peak / steeper rise, in blood glucose concentration ; 4 diabetic blood glucose concentration, has slower fall / does not return to normal in 3 hours / is still high after 3 hours ; 5 compare two data points with x and y figures and units ;
2. [1] ẞ cells / pancreas / islets of Langerhans / hypothalamus ;
3. [1] negative feedback;
4. [2] A - glucose oxidase ; B - (hydrogen) peroxidase;
5. [2] biosensor - rapid / immediate / 2 seconds, reading or (more), accurate / precise / quantitative / numerical / sensitive or shows current blood glucose / re-usable ; dipstick – non-invasive / painless / less risk of infection / easy to use / cheap ;
6. [5] any five from: 1 (insulin) binds to receptors on, liver / muscle / adipose (cells / tissue / organ); 2 GLUT(4) added to membrane of, muscle / adipose, cells or (GLUT 4) increases, muscle / adipose, cell, permeability (to glucose); 3 glucokinase phosphorylates glucose in liver cells or increased (rate of) diffusion of glucose into liver cells ; 4 more / faster, respiration of glucose ; 5 activates glycogen synthase / causes glycogenesis / causes glycogen synthesis ; 6 causes, lipid / triglyceride / fatty acid, synthesis or decreases, glycogenolysis / lipolysis / gluconeogenesis ; 7 blood glucose concentration decreases ;