5.3 Development of Medicines

Having a high proportion of body fat can lead to a person becoming obese. People with a BMI over 30 are considered to be obese.

Suggest why BMI is not always an accurate indication of health and body fat levels.

(2)

(4)

 

(3)

The information in Table 1 below shows some information about two types of treatment for cardiovascular disease.

Table 1

Use of stents	Heart bypass surgery
Minimally invasive operation	Surgery requires general anaesthetic
Typically one is fitted at a time	Multiple arteries can be unblocked in a single surgery
Straight-forward procedure and relatively short recovery time	There can be complications post-surgery including infection
Required to take anti-clotting medication following surgery	Required to take statins to lower blood cholesterol levels following surgery

Explain why a patient might opt for a stent rather than bypass surgery to treat cardiovascular disease.

Use information in the table above and your own knowledge in your answer.

Before medication can be manufactured and sold on a large scale, the drugs go through a rigorous trial process.

(2)

As with other drugs, antibiotics must go through a multi-step clinical trial process. 

Some researchers are trying to create alternative antibiotics to those currently being mass-produced. One possible source of antibiotics can be found in natural substances that have antimicrobial properties.

The graph in Figure 1 shows the effectiveness of two different types of herbs when used to kill bacteria: coriander and garlic. Also included in the graph is a control substance and a combination of both herbs together.

Figure 1

Describe the effectiveness of using different types of herbs as an antimicrobial substance.

Use figures from the graph in your answer.

The use of natural antimicrobial substances to destroy unwanted bacteria has increased in recent years. Some bacteria have become resistant to commonly used antibiotics, and therefore alternatives such as herbs are being explored. 

Use your knowledge of natural selection to explain why some bacteria are becoming resistant to antibiotics.

Hepatitis B is an infectious viral disease which infects the liver.

A double-blind trial was carried out to assess the effectiveness of using monoclonal antibodies to treat patients with a hepatitis B infection.

During the trial referred, a number of patients were admitted to the hospital because they felt unwell.

Information about these patients is shown in Figure 2.

Treatment	% of patients within each group admitted to hospital with hepatitis B
Group A: Placebo	6.2
Group B: Monoclonal antibody	1.8

Figure 2 

3 000 patients were involved in the trial.

Half the patients (Group A) were given the placebo.

Half the patients (Group B) were given the monoclonal antibody being tested.

Outline how a double-blind trial would be carried out.

(3)

Higher Tier Only

(ii)

Explain how injecting a patient, suffering from hepatitis B, with a specific monoclonal antibody will help in their treatment.

(2)

(iii)

Obesity increases the risk of a person developing cardiovascular disease.

Losing weight can reduce the risk of this disease occurring.

Explain why exercise can cause weight loss.

Figure 1 shows a gastric band fitted to a stomach.

Figure 1

Explain how a gastric band helps a person to lose weight.

BMI and waist : hip ratio can be used to find out if a person is obese.

Figure 2 shows some data for two males.

male	BMI	waist : hip ratio
A	27.3	0.85
B	?	0.81

BMI is calculated using the equation:

               BMI = 

Male B has a mass of 72 kg and a height of 1.81 m.

Calculate the BMI of male B.

Give the answer to 3 significant figures.

(3)

(ii)

Figure 3 shows the interpretation of BMI values.

BMI range	interpretation
below 18.5	underweight
18.5 – 24.9	normal
25.0 – 29.9	overweight
30.0 and above	obese

     
     Figure 3

Males with a waist : hip ratio above 0.90 are defined as abdominally obese.

Explain what the BMI and waist : hip ratio for male A shows about his weight distribution.

(2)

LDL cholesterol is a type of cholesterol which increases the risk of heart disease.

Statins are drugs used to reduce LDL cholesterol levels.

Figure 1 shows the cholesterol levels in the blood of a man.

He started taking statins at the beginning of February and stopped taking them four months later.

Figure 1

Describe the effect of statins on LDL cholesterol levels in the blood.

Use data from the graph to support your answer.

(2)

(ii)

Use evidence from the graph to explain why statins are usually prescribed as life-long medication.

(2)

Which data can be used to calculate the man’s BMI?

Figure 1 shows how alcohol consumption increases the risk of developing liver cancer.

Someone who does not drink alcohol has a 1.0 risk of developing liver cancer.

Figure 1

One unit of alcohol contains 8 grams of alcohol.

Calculate the risk of developing liver cancer for someone who consumes 4 units of alcohol a day.

(2)

(ii)

Describe how cancer develops in the liver.

(2)

Some crop plants have been genetically engineered to produce toxic chemicals in their leaves.

Explain one advantage of producing these genetically modified crop plants.