B15. Drugs

Question 1

How do antibiotics kill bacteria?

Answer 1

1. Many antibiotics kill bacteria by disrupting the production of cell wall and so preventing bacteria from reproducing
2. Some interfere with protein synthesis and prevent bacterial growth

Question 2

Ways to minimise development of resistant bacteria

Answer 2

1. Use antibiotics only when essential

2. Ensure treatment / course of antibiotics is completed

Question 3

Effects of depressants (heroin, alcohol)

Answer 3

1. Slow down central nervous system, lengthen reaction time
2. Relieve pain
3. Cause feelings of drowsiness and euphoria

Question 4

Withdrawal symptoms - heroin

Answer 4

1. Sweating
2. Abdominal cramping
3. Diarrhoea
4. Vomiting
5. Anxiety

Question 5

How does heroin affect the nervous system?

Answer 5

By mimicking the neurotransmitter in synapses in the brain, stimulating the receptor molecules to release dopamine; this gives a short-lived high

Question 6

Withdrawal symptoms - alcoholism

Answer 6

1. Sweating
2. High pulse rate
3. Tremors
4. Delirium

Question 7

Effects of stimulants (nicotine)

Answer 7

1. Speeds up action of nervous system

2. Users feel more alert

Question 8

How can tobacco smoking cause coronary heart disease?

Answer 8

Nicotine narrows blood vessels and can increase blood pressure, resulting in greater chances of thrombus forming and developing CHD

Question 9

Chronic Obstructive Pulmonary Disease (COPD)

Answer 9

COPD includes chronic bronchitis and emphysema. It causes breathlessness, frequent chest infections, and persistent cough with phlegm.
1. Chronic bronchitis:
Tar paralyses cilia, so excess mucus collects in the bronchi, leading to inflammation and smokers’ cough
*tar contains chemicals that are carcinogenic (can cause cancer)
2. Emphysema - the breakdown of alveoli:
Substances in smoke weaken alveoli walls, coughing bursts weakened walls, so surface area for gas exchange decreases, making it difficult to get enough oxygen into the blood

Question 10

Why do testosterone and anabolic steroids improve sporting performance?

Answer 10

1. They cause more proteins to be made in the muscles, so muscles become larger and stronger (increase muscle development)
2. Testosterone increases bone mass; anabolic steroids lower body fat

Question 11

10 roles of liver

Answer 11

1. Regulation of blood sugar level
2. Production of bile
3. Deamination
4. Storage of iron from breakdown of RBC and haemoglobin
5. Manufacture of plasma protein (eg. fibrinogen) from amino acids
6. Storage of vitamins A, B, D, E, K
7. Storage of glycogen
8. Storage of potassium
9. Production of cholesterol, needed to make and repair cell membranes
10. Breaks down harmful substances (eg. alcohol, drugs)