15. Drugs

• Drug - any substance taken into the body that modifies or affects chemical reactions in the body
• Antibiotics:

  • work by disrupting the cell wall formation of the bacteria, but no of human cell
  • some bacteria are resistant to antibiotics = reduces the effectiveness of antibiotics
  • development of resistant bacteria (MRSA) can be minised by using antibiotic only when essential & ensuring treatment is complete
  • don't work on viruses - they don't have a cell wall & make host cell perform their task
• Excessive use of alcohol and heroin abuse:

  • powerful depressant drugs
  • addiction and withdrawal symptoms
  • negative social implication (e.g. crime)
  • slows down reaction time and self control --> binds with the receptor itself or inhibit release of neurotransmitter (heroin)
  • injecting heroin = infections such as HIV
  • excessive alcohol consumption = liver damage
• Smoking:

  • tobacco smoking can cause: chronic obstructive pulmonary disease (COPD), lung cancer, coronary heart disease
  • nicotine: increase amount of adrenaline increased = increase heart beat = heart stress = heart disease
  • carbon monoxide: binds with haemoglobin which prevent it from binding with oxygen
  • tar: prevent cilia from working = dirt can't be removed, can cause cancer
• Liver - the site of break down of alcohol and other toxins
• Hormones improving sport performances:

  • anabolic steroids: help build muscle tissue, increase body mass
  • testosterone: improve muscle strength & size, increasing energy levels & hand-eye coordination