DRUGS

WHAT IS MEANT BY THE TERM DRUG?

• Drugs: any substance taken into the body that modifies or affects chemical reactions in the body.

• Synthetic or natural. Many come from plants. 

• Drugs for medical use – useful to relieve pain etc.• Misuse of drugs – can cause to themselves and others

ANTIBIOTICS

• Antibiotic: A drug that kills bacteria in the human body, without damaging human cells.

• Often made from fungi (which probably make them to kill bacteria living nearby)

Competition(decomposers)• First antibiotic discovered was Penicillin from fungus Penicillium, often

found on decaying fruit.• Penicillin kills bacteria by stopping them making their cell walls.

BACTERIA EVOLVE VERY FAST

• Important to find more and more beneficial antibiotics.• Evolution plays a part in this. The more we as humans use antibiotics

the faster bacteria evolve to be resistant. Selective Pressures.

• Viruses cannot be treated by antibiotics• Why?• Antibiotics work by damaging the cell walls of bacteria....but viruses

don't have cell walls

HOW CAN WE TEST ANTIBIOTICS

• Petri dish with agar jelly.• Bacteria growing on agar jelly. (for example Typhoid Fever)• White discs of filter paper soaked in antibiotics• The bacteria will not be able to grow near the filter papaer/antibiotic

• This shows the antibiotic is effective

WHAT IS HEROIN?

• Opium poppies produce opium• Opium contains morphine and codeine (used for pain relief)• Raw Opium is used to make heroin

• Heroin can be highly addictive• Causing dependency• Stopping causes physical and psychological symptoms

HEROIN

• Heroin is a depressant. A drug that inhibits the nervous system and slows it down.

• Slows down brain functions, reduces pain and slows down breathing

• Why do people misuse Heroin?• To gain a feeling of Euphoria.

HEROIN MISUSE

• People can become addicted• This causes social problems

• Heroin is often injected into veins. Dangerous because needles often aren't sterile

• Can allow viruses to enter the body. Such as Hepatitus and HIV

HEROIN IN THE BRAIN

• Neurotransmitters transfer nerve impulses across synapses

• One neurone to another. 

• Endorphins – a group of neurotransmitters Help reduce sensations of painAffect moodReduce sensations of hunger/thirst

• Feel-good effect

• Heroin metabolises to morphine in the brain.• Morphine fits in to some of the endorhpin

receptorsFor this reason heroin makes people feel good

But Heroin can prevent production of Endorphins. So stopping taking Heroin, can cause side effects

ALCOHOL CONSUMPTION

• Alcohol is a common, mainstream drug

• Alcohol is quickly absorbed through the stomach wall and spread around the body in blood.

• Eventually being broken down by the liver.• In general – one drink can be broken down in one hour

DANGEROUS EFFECTS OF ALCOHOL

• Reaction time is reduced. Because it is a depressant

• Increase Aggression. People react differently using alcohol. Some can become aggressive

• Large intakes can kill. Alcohol poisoning. Sometimes vomiting while unconsious 

ALCOHOLISM

• A disease where a person cannot manage without alcohol

• Possibly genetic reasons why some people become alcoholic and others not• Also lifestyle, stress, personality.

• Alcoholics need to drink large quantities regularly. This causes damage to all cells as well as liver. (Alcohol is poisonous to cells)

Cirrhosis. A disease of the liver in which the cells are permanently damaged

EFFECTS OF ALCOHOL ON BRAIN

• Excessive alcohol consumption can: • Cause memory loss and confusion• - by drawing water out of cells by osmosis. When this happens to brain

cells, they shrink. Possibly resulting in permanent damage

• Alcohol can stop the kidneys releasing a hormone which prevents the body from allowing too much water to leave the body in urine

Alcohol consumptionPrevents kidneys

realeasing a hormone ADH

Allows water to be removed in urine

Alcohol = dilute urine(low levels of water in

blood)

ANABOLIC STEROIDS

• Steroids are a type of hormone.• Inc. Testosterone, oestrogen and progerterone (reproduction)

• Steroids allow large molecules to form from small ones.  These metabolic reactions are called Anabolic Reactions

• (metabolic reaction = the chemical reactons that take place inside living organisms)

ANABOLIC STEROIDS

• Testosterone causes more proteins to be made from amino acids• Muscle growth, increased aggression

• Many sports test for Anabolic Steroids.(urine/blood). It is banned

• Risks: decrease immune systems ability to destroy pathogens. • Liver damage.

• Presence of Anabolic Steroids can stay in the body for a long time after consumption

SMOKING TOBACCO

• Nicotine – an addictive drug found in tobacco smoke• It is a stimulant: a drug which makes the nervous system work faster.

• Effects: damages the circulatory system, making blood vessel become narrower.

Increasing blood pressure and leading to hypertension (High blood pressure)

• Greater chance of developing heart diseases

CARCINOGENS

• Carcinogens: a substance that increases the risk of a person's body developing cancer

• Tar, contains many chemicals – some a carcinogens• Can have affects on the cells of the respiratory passages – causing

them to divide over and over again, forming a lump / tumour

Cells may break away and spread the tumour to other areas

SMOKE

• Carbon monoxide diffuses from the lungs into the blood, and combines with haemoglobin in red blood cells

• Resulting in less oxygen being carried. Depriving cells of sufficient oxygen

• Smoke carries carbon particles which get trapped in the lung. WBC try to remove them by secreting chemicals. But these chemicals can do serious damage to the lungs

Alveoli breakdown, less surface area. Emphysema – disease in which the walls of the alveoli break down, reducing surface area for gas exchange.

• Smoke also contain chemicals which can damage cilia and goblet cells

SMOKING AND HEART DISEASE

• Smoking increases risk of High Blood Pressure• Blood vessels become thicker by absorbing smoke chemicals• They can no longer recoil and stretch easily as blood flows through

• Blood clot can form inside vessels

SMOKING AND LUNG CANCER

• Lung cancer can develop from smoking or passively inhaling other peoples smoke

• Correlations used over time to show a link.

• Chemicals in cigarettes can affect DNA in cell nuclei.• By making cells divide over and over to form tumours (Carcinnogens)