Diabetes

There are two types of diabetes mellitus, type I and type II.

Which option is true for both type I and type II diabetes mellitus?

A If left untreated, they result in the presence of glucose in the urine.

B They are caused by destruction of cells in the liver.

C They are caused by reduced sensitivity of cells to insulin.

D They are known as insulin-dependent diabetes.

Your answer

This is a photomicrograph of a section of mouse pancreas.

Identify the structures labelled F and G.

F........

G........

Glycosylated haemoglobin (HbA1c) is used to monitor how well a patient’s diabetes is controlled.

HbA1c was traditionally measured as a percentage, but it is now measured in mmol mol^–1, which is the amount of glucose (in mmol) per mole of haemoglobin.

A patient was told that their HbA1c was 42 mmol mol^–1.

They found a table of HbA1c values used in diagnosis.

The equation can be used to convert values in % to mmol mol^–1. (i)

HbA1c (mmol mol^–1) = (HbA1c (%) – 2.14) × 10.929

Calculate the patient’s HbA1c concentration in %.

Give your answer to 2 significant figures.

Use your answer to part (i) to determine the status of the patient, based on the values in the table.

* Semaglutide is a new form of anti-diabetes medication that is prescribed as a once-weekly injection for treatment of Type 2 diabetes.

Clinical trials have shown that semaglutide causes a significant reduction in HbA1c and body mass compared with existing treatments, such as daily insulin injections and other anti-diabetic drug treatments.

Other clinical trials have shown that semaglutide causes a significant reduction in kidney damage but a significant increase in retina damage compared with placebos.

Evaluate the potential advantages and disadvantages of semaglutide for treatment of Type 2 diabetes.

Extra answer space if required.

The kidney is an organ of filtration and osmoregulation, but its functions can be hindered by several different diseases.

A student dissected a kidney. One half of the dissected kidney is shown in Fig. 3.1 on the Insert.

Draw a simple diagram of the dissected kidney, shown in Fig. 3.1, in the space below.

On your diagram, label the cortex, renal pyramids and ureter.

Osmoregulation in the kidney can be affected by a condition called syndrome of inappropriate antidiuresis (SIAD).

shows how ADH concentration in the blood changes with blood sodium ion (Na +) Fig. 3.2 concentration in:

• normal homeostasis

• people with one type of SIAD.

Na + ion concentration in the blood (mmol dm^–3)

Explain the conclusions you can make from Fig. 3.2 about the effect of SIAD on osmoregulation.

Glucose is normally reabsorbed from the proximal convoluted tubule of the kidney.

In some conditions, such as diabetes mellitus, glucose remains in the filtrate and can be detected in urine.

Biosensors are used to detect glucose in urine.

The sentences describe how biosensors can detect glucose in urine.

Complete the sentences using the most appropriate words or phrases.

Glucose test strips contain an enzyme called........,

which converts glucose to gluconic acid and hydrogen peroxide. Another enzyme,

........, converts hydrogen peroxide to oxygen and water. Oxygen

reacts with a chemical on the test strip to produce a colour change. In recent years, a

polarimeter device has been developed. The polarimeter gives a digital readout of the

glucose concentration in urine, in units such as........

Kidney failure has a variety of possible causes.

This is a description of kidney failure:

The person noticed their symptoms developing over a long period of time. Unusual tissue, not normally found on a healthy kidney, could be seen on the outside of the kidney.

Suggest and give a reason for a possible cause of kidney failure in this person.

Outline the possible future use of stem cells in kidney transplant surgery.

Fig. 1.1 shows a light micrograph of pancreatic tissue.

State one function of the cell labelled X.

Name the two different types of cell in the region labelled Y.

The diameter of one region of pancreatic tissue is represented by the line Z.

Calculate the actual diameter of the region labelled Z.

Give your answer in m and to 3 significant figures.

Actual diameter =........ m

A stage micrometer can be used when measuring the linear dimensions of cells, such as those of the pancreatic tissue, viewed under a light microscope.

Outline how a stage micrometer is used to measure the linear dimensions of cells.

The pancreas has an essential role in controlling blood glucose concentration.

A person was given a glucose tolerance test. Two months later, the same person was given a fasting blood glucose test. The table shows the results of the two tests.

Suggest what conclusions can be made from the results of the two tests.

Fig. 1.2

Complete the structure of -glucose in Fig. 1.2 to show all of the atoms in the structure.

The table lists glucose and two other carbohydrate molecules: lactose and amylose.

Fill in the table to show, for each carbohydrate, a reagent that would give a positive result when used in a test to help identify the carbohydrate and the number of glycosidic bonds in

Which of the options, A to D, is true of type 2 diabetes?

A caused by autoimmunity

B present from birth

C rapid onset

D slow onset