Transcript Review3

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CH 112
Overview of CH 10 and CH 14
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Chapter 10 Highlights
 During
exercise, the muscles use ATP to
contract.
 ATP
runs out pretty quickly but can be
replenished rapidly by phosphocreatine.
 Exercise
that lasts less than about 10
seconds can be sustained by ATP and
phosphocreatine (the phosphagen system).
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Chapter 10 Highlights
 Exercise
that lasts more than 10 seconds
requires the use of metabolism to restore ATP,
either through the aerobic or anaerobic
pathway.
 The
aerobic pathway is much more efficient than
the anaerobic pathway at producing ATP.
 The
rate at which oxygen is delivered to the
muscles (VO2 max) is one of the limits to the
level of aerobic activity.
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Chapter 10 Highlights (cont)
 During
aerobic sports, fuels such as fats,
carbs, and proteins are completely oxidized
to CO2 and H2O.
 During
anaerobic sports, only glucose can
be metabolized, and it ends up as lactic
acid.
 Athletic
performance enhancers include
mechanical, nutritional, physiological, and
pharmacological aids.
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The Molecular Basis of Exercise
 ATP, the
Cell’s Energy Currency
 Phosphocreatine
 Rapidly restores ATP
 Limited capacity (~10 seconds)
 Fuels that Power Exercise
 Primarily
fats and carbohydrates (glucose
or glycogen).
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The Molecular Basis of Exercise
 Mobilization
 During
of Fuels
glycolysis, glucose is oxidized to
pyruvate and ATP is produced.
 Pyruvate can be oxidized in the efficient
aerobic pathway (cellular respiration) or
converted to lactic acid in the anaerobic
pathway (fermentation).
 The rate at which oxygen is delivered to the
muscles (VO2 max) dictates the level of
activity that can be sustained under aerobic
conditions.
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Nutritional Aids
 Gatorade
(During)
 Provides
carbohydrates, water, and
electrolytes
 Chocolate
 4:1
Milk (After)
carb to protein ratio is optimal
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Nutritional Aids by Sport
 Creatine
(power athletes)
 Increases
stores of phosphocreatine, the
muscle’s quickest energy reserve
 Bicarbonate
 Helps
 Carbo
(anaerobic athletes)
buffer lactic acid
Loading (endurance athletes)
 Increases
the stores of glycogen
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Physiological Aids
 Improving
 Blood
Oxygen Delivery
Doping: red blood cells are removed
several weeks prior to competition; body
responds by making more red blood cells;
right before competition, athlete receives a
blood transfusion.
 Erythropoietin (EPO): hormone that promotes
the production of red blood cells.
 Both result in increased hematocrit.
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Effect of EPO on Hematocrit
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Pharmacological Aids
 Stimulants
 Improve
alertness and energy level
 Some, like caffeine, are legal
 Others, like amphetamines, are illegal
 Building
muscle mass
 Anabolic steroids: structurally similar to the
male sex hormone testosterone
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Anabolic Steroids
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Chapter 14 Highlights
 Chemistry
has played a large role in
warfare throughout history, including in the
development of conventional explosives,
chemical weapons, and biological
weapons.
 Explosives
can be classified as low
explosives (which burn) and high
explosives (which detonate).
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Chapter 14 Highlights (cont)
 Chemical
weapons are classified
according to mode of action, including lung
irritants (such as chlorine gas), vesicants
(such as mustard gas), and nerve agents
(such as VX).
 Biological
weapons, which are derived
from living organisms, include viruses,
bacteria, and toxic compounds found in
nature.
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Early Use of Chemistry in Warfare
 Low
Explosives: e.g., gun powder
 An explosive mixture of potassium nitrate,
charcoal, and sulfur developed by the Chinese
in the 10th century
 High
Explosives
 Exemplified by nitroglycerine, which contains
internal nitro groups (-NO2) that rapidly oxidize
the rest of the molecule
 Detonation results in a volume expansion
because of a rapid release of heat and gaseous
products.
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Factors Affecting Volume of a Gas
Fig 14.3
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Chemical Warfare Agents
 Definition
 Chemical
substances, whether gaseous,
liquid, or solid, which are used because of
their direct toxic effects on humans,
animals, or plants
 Classes
 Classified
by their mode of action: lung
irritants, vesicants, respiratory poisons,
nerve agents, hallucinogens, and herbicides
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Classes of Chemical Weapons
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Chemical Warfare Agents (cont)
 Lung
Irritants
 Damage
lung tissue directly or via reaction
to produce a corrosive compound
 Exemplified by chlorine gas (Cl2)
 Cl2 is a powerful oxidizing agent and also
reacts with H2O in the lungs to form
hypochlorous acid (HOCl), which oxidizes
cellular molecules.
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Action of Hypochlorous Acid
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Chemical Warfare Agents (cont)
 Vesicants
 Produce
painful blisters within any exposed
tissue
 Exemplified by mustard gas
 Use of mustard gas in warfare led to the
discovery that related compounds are
useful anticancer drugs because they
damage DNA
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Action of Nitrogen Mustard
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Chemical Warfare Agents (cont)
 Nerve
Agents
 Inactivate
the enzyme acetylcholinesterase,
which is essential for muscle contraction.
The result is rapid death by respiratory
paralysis.
 Exemplified by VX
 Atropine acts as an antidote for nerve
agents by blocking the acetylcholine
receptor.
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Action of Atropine
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Biological Warfare Agents
 Definition
 Living
organisms such as bacteria or toxic
material derived from them, which are
intended to cause disease or death in
humans, animals, or plants
 Early
Examples
 Disease-infected
clothing
 Arrow poisons
cadavers, blankets, and
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Biological Warfare Agents (cont)
 Types
of Modern Bioweapons
 Bacteria:
e.g., Bacillus anthracis, used by
unknown parties to perpetrate the 2001
anthrax attacks.
 Viruses: e.g., variola, which causes smallpox
and may be an emerging threat because
individuals are no longer vaccinated against
it.
 Toxins: e.g., botulinum toxin, produced by
the bacterium Clostridium botulinum; lethal
at doses of 1 ng/kg.
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Biological Warfare Agents (cont)
 Treatment
for Modern Bioweapons
 Bacteria: antibiotics
 Viruses: vaccination