A2 Biology Topic 7 Performance enhancing drugs

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A2 Biology Topic 7 Performance enhancing drugs
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Banned substances and practices
Stimulants
Anabolic steroids
Hormone agonists
Hormones and releasing factors
Diuretics
Beta-2 agonists
Blood doping
Narcotics
Gene doping
Beta blockers
Is it an infringement of athletes human rights to
be required to give blood and urine samples?
Page reference 178-179 Edexcel A2 Biology
(concept) textbook
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Steroid hormones
Pass through the plasma membrane and stimulate
protein synthesis
Other steroid molecules
Steroid hormones
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Mechanism of action of steroid hormones
steroid hormone
cell surface membrane
Hormone enters cell and binds with receptor
Complex binds to DNA and acts as a transcription
factor
nuclear membrane
receptor
enters nucleus
hormone-receptor complex
Switches on a gene for synthesis of a protein
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Testosterone
Stimulates protein synthesis Results in bigger
and stronger muscles
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Anabolic steroids
Natural testosterone is quickly broken
down.Testosterone is modified to produce drugs
that remain for longer in the bodyThese
synthetic anabolic steroids are illegal.
testosterone
nandrolone
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Side-effects of using anabolic steroids

• Infertility due to disruption of normal hormone
  production
• - disrupted menstrual cycle
• - reduced sperm production
• impotenceIn addition- liver damage
• - high blood pressure
• - heart attacks
• - increased aggression

21 year old body builder A and B Severe acne
conglobata C After 8 weeks off steroids and with
antibiotics
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Peptide hormones
Peptide hormones do not enter the cell. They
bind to receptors on the cell surface
membrane.They also act to switch genes on or
off.
Human erythropoietin
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Mechanism of action of peptide hormones
peptide hormone
receptor
cell surface membrane
Secondary messenger activated initiates a
protein kinase cascade
acts as a transcription factor which switches on
gene for a specific protein
Inactive secondary messenger eg. cAMP
enters nucleus
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Erythropoietin
Erythropoietin is synthesised in the
kidneys Causes the synthesis of enzymes required
for synthesis of red blood cells (erythrocytes)
in bone marrow.Useful for treating anaemia.
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Use of erythropoeitin
Increases number of blood cells and therefore
enhances oxygen supply to muscles. Improvement
of 10 in aerobic performance Use is popular
with endurance athletes and cyclists
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Side-effects of overuse of erythropoietin
Excess of red blood cells can lead to strokes and
heart attacks . Attacks most common at night due
to low heart rate. Thought to have caused the
unexpected deaths of 18 european cyclists between
1987 -1991 . Abuse difficult to prove as it is
naturally occurring.
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Ethics of performance-enhancing drugs
Problems with deciding on what is illegal
Ethical questions
Creatine is not banned Classed as a nutritional
supplement Can cause kidney damage and high blood
pressure
Is everything acceptable in the pursuit of
sporting excellence?
Erythropoietin is banned Is a naturally
occurring hormone Can cause strokes and heart
attacks
Isnt it the choice of the athlete to risk using
drugs or not?
Blood doping banned Donating, storing and
transfusing own blood before competition
Do use of performance- enhancing drugs improve or
ruin competition?
High altitude training not banned Increases
number of red blood cells. Caused by natural
increase in erythropoietin production.
Are there circumstances when drug use is
acceptable?
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Essay
Read pages 182 183 (of concept approach
textbook) and answer question 2 on page
183 Describe an absolutist and a relativist
ethical position on the proposal to set a maximum
total red blood cell count for athlete rather
than measure erythropoietin levels.