Transcript Drugs - divaparekh

Objectives:
*Define the term drug
**Describe the medicinal use of antibiotics for the
treatment of bacterial infection
***Explain why antibiotics kill bacteria but not
Viruses
Starter:
What is a drug?
Dangers of drugs
Drugs
• A drug is something that alters or
influences the chemical reactions in
the body.
• Recreational drugs are taken for
pleasurable reasons.
• Drugs are either depressant or
stimulants
 Alcohol
 Cannabis
 Cocaine and heroin
 Tobacco
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Alcohol and tobacco are legal drugs.
Cannabis, cocaine and heroine are illegal.
People can become addicted to a drug.
They feel dependent on it.
Drug addiction can have long term effects.
They can affect the brain and liver.
The liver is damaged as its job is destroying
harmful chemicals within the body.
Legal drugs can be misused and become a
danger.
Starter
What is a drug?
Name 1 that is legal
Name 1 that is illegal
http://www.youtube.com/watch?v=4jH1zqlfQI
•A drug is any chemical that alters how our body works.
•Drugs that affect our CNS control the movement of
chemicals across the synapse. These are called
recreational drugs e.g. hallucinogens
•The natural chemicals in our nervous system have shapes
that fit like a key in a lock .
•Drugs have a similar shape to these chemicals
and mimic (copy) what they do.
I can describe different types of drugs and why some people use them for recreational drugs
Task Two
Cigarette poisons
• Tobacco contains
many different
substances including
nicotine, tar and
carbon monoxide in
smoke particles
Nicotine-
affects
the brain. It is
addictive.
Tar – is a poison that causes cancer. Its a
carcinogen.
Cigarette smoke often causes lung cancer, but
can risk development of other cancers.
Carbon monoxide- takes the place of
oxygen in red blood cells, so the blood carries
less oxygen. This can harm body cells.
In pregnant women this can be dangerous as
the baby will get less oxygen, it may not grow
properly and have a low birth weight. A person
who smokes is likely to have heart disease.
Smoke particles – burnt fragments of tobacco
Accumulate in the lung tissue and stimulate
body’s defence system to remove them.
Lung diseases
• A smoker get lung infections.
• In the bronchitis, the smokers
bronchi inflames.
• Lots of mucus is produced.
• This can cause excessive
coughing.
• The air sacs lose stretchiness.
• It is difficult to get oxygen into
the blood.
• This is called emphysema.
• Someone with this condition
may have to breathe oxygen
from a cylinder.
 Alcohol:
 Quickly absorbed through
the cell wall of stomachcarried by bloodeventually broken down by
liver-but this takes quite a
long time.
 Alc. lengthens reaction
time, it is a depressant, to
respond to a stimulus.
 Increases aggression in
some,
 More than 0.8 over 2
hours-unconscious-death
is caused by vomiting
while unconscious-airways
are blocked
 Alcoholism –dangerous
disease.
 Liver cirrhosis, where fibres
grow in liver, can be fatal.
 Damages brain too. Alcohol
draws water out of cell by
osmosis, when it happens to
brain cells, they shrink and
may be irreversibly damaged.
 Alcohol also inhibits the
release of a hormone which
stops kidney from allowing
too much of water to leave
the body in the urine-dilute
urine-so low levels of water in
the blood.
 Most of the antibiotics
are made from Fungi.
 Bacteria n Fungi-both r
decomposer-they
compete for foods
 We use the chemical
warfare system of
Fungus to fight with
bacteria
 Penicillin was the first
discovered antibiotic
from fungus Penicillium
 It kills bacteria by
stopping them making
their cell walls.
 Misuse of antibiotics-
against viral as well as
bacterial diseases-made
it resistant
 Need newer antibiotics
Pathogens & Antibiotics
Microorganisms
• These are living things that we cannot see.
• They include fungus, bacteria and viruses
• Their cells are smaller than ours.
• You can’t see bacteria clearly.
• Viruses are even smaller.
• There are some viruses that can get into
bacteria, so bacteria can also get ill.
Antibiotics
•These are drugs that kill bacteria and fungus
inside your body.
•They don’t kill viruses.
•Antibiotics include penicillin and
streptomycin.
•We different ones as they don't all work
equally well against all kind of bacteria.
• The antibiotics that can only kill specific
bacteria are or fungus are called narrow
spectrum antibiotics. Broad spectrum
antibiotics can kill a larger variety of
pathogen
Microorganisms and disease
• Some bacteria and viruses can cause disease.
• A microorganism that causes disease is called a
pathogen.
• If bacteria can get into the body, it reproduces
rapidly.
• They produce toxins that make you feel ill.
• They are carried in the blood.
• A virus can get into a cell and reproduce there.
• When too much is produced they can burst out
of the cell and destroy it.
• Antibiotics work either by damaging the
cell wall or inhibiting the metabolism in a
cell of the pathogen.
• Since viruses do not have cells and they
occupy host cells antibiotics can not
work on them .
• If they did the host cell would be
affected
Drugs against disease
Painkillers
• A drug used to get rid of pain.
• You can buy these, e.g. Aspirin,
paracetamol and ibuprofen.
• They reduce symptoms of whatever
is wrong with you.
Antiviral
•Viruses are more difficult to kill.
•If they go inside a cell they are
impossible to kill it without killing the
cell.
• Antivirals are used to kill viruses.
Sources of antibiotics
• Penicillin is made from a fungus.
• The drug companies are always on
the look out for new antibiotics.
• Nowadays, most antibiotics are made
chemically.
• This is better then extracting them
from fungi or other organisms
because you know what you're
getting.
• If you take it from fungus, you don’t
know the strength of it.
• Making it chemically means you
know its pure