Histrionicotoxin

I read this information from Organic Chemistry. Histrionicotoxin is a diyne isolated in small quantities from the skin of Dendrobates histrionicus, a colorful South American frog. This toxin, secreted by the frog as a natural defense mechanism, was used as a poison on arrow tips by the Choco tribe of South America. These small “poison dart” frogs inhabit the moist humid floor of tropical rainforests, and are commonly found in western Ecuador and Colombia. Histrionicotoxin acts by interfering with nerve transmission in mammals, resulting in prolonged muscle contraction.

Asthma and Leukotrienes

I read this information from Organic Chemistry. Asthma is an obstructive lung disease that affects millions of Americans. Because it involves episodic constriction of small airways, bronchodilators such as albuterol and inhaled steroids
reduced inflammation )are used to treat symptoms by widening airways.Leukotrienes are molecules that contribute to the asthmatic response. Structure determination and chemical synthesis were difficult because leukotrienes are highly unstable and extremely potent, and are therefore present in tissues in exceedingly small amounts.

Ethanol

I read this information from Organic Chemistry. Ethanol formed by the fermentation of the carbohydrates in grains, grapes, and potatoes, is the alcohol present in alcoholic beverages. It is perhaps the first organic compound synthesized by human, because alcohol production has been known for at least 4000 years. Ethanol depresses the central nervous system, increases the production of stomach acid, and dilates blood vessels, producing a flushed appearance. Ethanol is also a common laboratory solvent, which is sometimes made unfit to ingest by adding small amount of benzene or methanol. Ethanol is used as a gasoline additive because it readily combusts with the release of energy.

Vitamin A

I read this information from Organic Chemistry. Vitamin A or retinol helps to maintain the health of mucous membranes and the skin, so many anti-aging creams contain vitamin A. A deficiency of this vitamin leads to a loss of night vision. Vitamin A may be obtained directly from the diet. In addition, β-carotene, the orange pigment found in many plant including carrots, is readily converted to vitamin A in our bodies. Ingesting a moderate excess of vitamin A does not cause any harm, but a large excess causes headaches, loss of appetite, and even death. Early Arctic explorers who ate polar bear livers, which contain an unusually large amount of vitamin A are thought to have died from consuming too much vitamin A.

Vitamin

I read this information from Organic Chemistry. The name vitamin was first used in 1912 by the Polish chemist Casimir Funk, who called them vitamines because he thought that they all contained an amine functional group. Later the word was shortened to vitamin, because some are amines but others, like vitamins A and C, are not. Vitamins are organic compounds needed in small amounts for normal cell function. Our bodies cannot synthesize these compound, so they must be obtained in the diet. Most vitamins are identified by letter, such as A, C, D, E, and K. There are several different B vitamins, though, so a subscript is added to distinguish them: for example, B₁, B₂, and B₁₂.

How a diet high in cholesterol may cause cardiovascular disorders.

I read this information from PRE-U TEXT STPM BILOLOGY, a diet rich in cholesterol may result in high blood cholesterol. CO, nicotine, hypertension and high blood cholesterol level cause damage to arterial endothelium. There is invasion by monocytes which develop into macrophages. Macrophages ingest cholesterol from LDLs. Smooth muscle cells also ingest cholesterol. The macrophages and smooth muscle cells transformed into foam cells. The foam cells together with accumulation of lipid( mainly cholesterol), Ca²⁺ and fibrous deposits from the athermatous plaque which is covered by a fibrous cap. It protrudes into the arterial lumen. The plaque causes narrowing of the arterial lumen, reduces oxygen supply to the heart and increases the risk of developing cardiovascular disorders example heart attack.

The effects of cocaine on the nervous system

I read this information from PRE-U TEXT STPM BILOLOGY, there are some of the effects of cocaine on the nervous system. It begin when drug users take in cocaine example snorting (inhaling) or smoking, cocaine enters into the synaptic cleft and binds to the transport molecules. This blocks the reuptake of dopamine by the presynaptic cell. The level of dopamine is higher than normal and remains longer in the synapse. This stimulates the pleasure pathway which gives drug users an intense feeling of euphoria and increased sense of energy. The feeling last for 5-30 minutes. The users then begin to feel irritable, restless and depressed. To overcome these symptoms, users have to repeat the usage of cocaine. With continued cocaine use, the body responds to the ‘excess’ supply in the synaptic cleft by producing less neurotransmitter dopamine and decreasing the numbers of receptors. The cocaine users then experience withdrawal symptoms. They become extremely dependent (addicted) to the drug and increase the cocaine intake to produce the euphoric effect. High doses of cocaine can cause nasal bleeding (from snorting), seizures, cardiac and respiratory arrest, as well as brain damage. Babies born to addict may suffer from developmental and neurological problems. Diseases such as hepatitis B and AIDS are spread when drug addicts share needles.