+

CH 112 Overview of CH 10 and CH 14

+

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).

Chapter 10 HighlightsChapter 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.

Chapter 10 HighlightsChapter 10 Highlights

+

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.

Chapter 10 Highlights (cont)Chapter 10 Highlights (cont)

+

ATP, the Cell’s Energy CurrencyPhosphocreatine

Rapidly restores ATPLimited capacity (~10 seconds)

Fuels that Power ExercisePrimarily fats and carbohydrates

(glucose or glycogen).

The Molecular Basis of Exercise

+

Mobilization of FuelsDuring 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.

The Molecular Basis of Exercise

+

Gatorade (During)Provides carbohydrates, water, and

electrolytes

Nutritional Aids

Chocolate Milk (After)4:1 carb to protein ratio is optimal

+

Creatine (power athletes) Increases stores of phosphocreatine, the

muscle’s quickest energy reserve

Nutritional Aids by Sport

Bicarbonate (anaerobic athletes)Helps buffer lactic acid

Carbo Loading (endurance athletes) Increases the stores of glycogen

+

Improving Oxygen DeliveryBlood 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.

Physiological Aids

+Effect of EPO on Hematocrit

+

Stimulants Improve alertness and energy levelSome, like caffeine, are legalOthers, like amphetamines, are illegal

Building muscle massAnabolic steroids: structurally similar to

the male sex hormone testosterone

Pharmacological Aids

+Anabolic Steroids

+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).

13

+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).

14

Biological weapons, which are derived from living organisms, include viruses, bacteria, and toxic compounds found in nature.

+

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.

15

Early Use of Chemistry in Warfare

+Factors Affecting Volume of a Gas

16

Fig 14.3

+Chemical Warfare Agents

DefinitionChemical substances, whether gaseous,

liquid, or solid, which are used because of their direct toxic effects on humans, animals, or plants

ClassesClassified by their mode of action: lung

irritants, vesicants, respiratory poisons, nerve agents, hallucinogens, and herbicides

17

+Classes of Chemical Weapons

18

+Chemical Warfare Agents (cont)

Lung IrritantsDamage 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

20

+Chemical Warfare Agents (cont)

VesicantsProduce painful blisters within any

exposed tissueExemplified by mustard gasUse of mustard gas in warfare led to the

discovery that related compounds are useful anticancer drugs because they damage DNA

21

+Action of Nitrogen Mustard

22

+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 VXAtropine acts as an antidote for nerve

agents by blocking the acetylcholine receptor.

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+Action of Atropine

24

+Biological Warfare Agents

DefinitionLiving organisms such as bacteria or

toxic material derived from them, which are intended to cause disease or death in humans, animals, or plants

Early ExamplesDisease-infected cadavers, blankets,

and clothingArrow poisons

25

+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: antibioticsViruses: vaccination

27