Write a conclusion----Which foods had which macromolecules?Conclusion?我英文那麽差怎麽可能会写那麽长的推论嘛?而且她连课都没讲解过耶!就叫我们写推论?T_T好苦啊~

Write a conclusion----Which foods had which macromolecules?Conclusion?我英文那麽差怎麽可能会写那麽长的推论嘛?而且她连课都没讲解过耶!就叫我们写推论?T_T好苦啊~
Write a conclusion----Which foods had which macromolecules?
Conclusion?我英文那麽差怎麽可能会写那麽长的推论嘛?而且她连课都没讲解过耶!就叫我们写推论?T_T好苦啊~

Write a conclusion----Which foods had which macromolecules?Conclusion?我英文那麽差怎麽可能会写那麽长的推论嘛?而且她连课都没讲解过耶!就叫我们写推论?T_T好苦啊~
RISK FACTORS
Many cancers are related to specific environmental and lifestyle factors that predispose a person to develop cancer.Accumulating data suggest that some of these risk factors initiate carcinogenesis,other risk factors act as promoters,and some risk factors both initiate and promote the disease process.
Air pollution
Air pollution has been linked to the development of cancer,particularly lung cancer.Persons living near industries that release toxic chemicals have a documented increased risk of cancer.Many outdoor air pollutants ¡ª such as arsenic,benzene,hydrocarbons,polyvinyl chlorides,and other industrial emissions as well as vehicle exhaust ¡ª have been studied for their carcinogenic properties.
Indoor air pollution,such as from cigarette smoke and radon,also poses an increased risk of cancer.In fact,indoor air pollution is considered to be more carcinogenic than outdoor air pollution.
Tobacco
Cigarette smoking increases the risk of lung cancer more than tenfold over that of nonsmokers by late middle age.Tobacco smoke contains nitrosamines and polycyclic hydrocarbons,two carcinogens that are known to cause mutations.The risk of lung cancer from cigarette smoking correlates directly with the duration of smoking and the number of cigarettes smoked per day.Tobacco smoke is also associated with laryngeal cancer and is considered a contributing factor in cancer of the bladder,pancreas,kidney,and cervix.Research also shows that a person who stops smoking decreases his or her risk of lung cancer.
Although the risk associated with pipe and cigar smoking is similar to that of cigarette smoking,some evidence suggests that the effects are less severe.Smoke from cigars and pipes is more alkaline.This alkalinity decreases nicotine absorption in the lungs and also is more irritating to the lungs,so that the smoker doesn't inhale as readily.
Inhalation of "secondhand" smoke,or passive smoking,by nonsmokers also increases the risk of lung and other cancers.Plus use of smokeless tobacco,in which the oral tissue directly absorbs nicotine and other carcinogens,is linked to an increase in oral cancers that seldom occur in persons who don't use the product.
Alcohol
Alcohol consumption,especially in conjunction with cigarette smoking,is commonly associated with cirrhosis of the liver,a precursor to hepatocellular cancer.The risk of breast and colorectal cancers also increases with alcohol consumption.Possible mechanisms for breast cancer development include impaired removal of carcinogens by the liver,impaired immune response,and interference with cell membrane permeability of the breast tissue.Alcohol stimulates rectal cell proliferation in rats,an observation that may help explain the increased incidence of colorectal cancer in humans.
Heavy use of alcohol and cigarette smoking synergistically increases the incidence of cancers of the mouth,larynx,pharynx,and esophagus.It's likely that alcohol acts as a solvent for the carcinogenic substances found in smoke,enhancing their absorption.
Sexual and reproductive behavior
Sexual practices have been linked to specific types of cancer.The age of first sexual intercourse and the number of sexual partners are positively correlated with a woman's risk of cervical cancer.Furthermore,a woman who has had only one sexual partner is at higher risk if that partner has had multiple partners.The suspected underlying mechanism here involves virus transmission,most likely human papilloma virus (HPV).HPV types 6 and 11 are associated with genital warts.HPV is the most common cause of abnormal Papanicolaou (Pap) smears,and cervical dysplasia is a direct precursor to squamous cell carcinoma of the cervix,both of which have been linked to HPV (especially types 16 and 31).
Occupation
Certain occupations,because of exposure to specific substances,increase the risk of cancer.Persons exposed to asbestos,such as insulation installers and miners,are at risk of a specific type of lung cancer.Asbestos also may act as a promoter for other carcinogens.Workers involved in the production of dyes,rubber,paint,and beta-naphthylamine are at increased risk of bladder cancer.
Ultraviolet radiation
Exposure to ultraviolet radiation,or sunlight,causes genetic mutation in the P53 control gene.Sunlight also releases tumor necrosis factor alpha in exposed skin,possibly diminishing the immune response.Ultraviolet sunlight is a direct cause of basal and squamous cell cancers of the skin.The amount of exposure to ultraviolet radiation also correlates with the type of cancer that develops.For example,cumulative exposure to ultraviolet sunlight is associated with basal and squamous cell skin cancer,and severe episodes of burning and blistering at a young age are associated with melanoma.
Ionizing radiation
Ionizing radiation (such as X-rays) is associated with acute leukemia,thyroid,breast,lung,stomach,colon,and urinary tract cancers as well as multiple myeloma.Low doses can cause DNA mutations and chromosomal abnormalities,and large doses can inhibit cell division.This damage can directly affect carbohydrate,protein,lipid,and nucleic acids (macromolecules),or it can act on intracellular water to produce free radicals that damage the macromolecules.
Ionizing radiation also can enhance the effects of genetic abnormalities.For example,it increases the risk of cancer in persons with a genetic abnormality that affects DNA repair mechanisms.Other compounding variables include the part and percentage of the body exposed,the person's age,hormonal balance,prescribed drugs and preexisting or concurrent conditions.
Hormones
Hormones ¡ª specifically the sex steroid hormones estrogen,progesterone,and testosterone ¡ª have been implicated as promoters of breast,endometrial,ovarian,or prostate cancer.
Estrogen,which stimulates the proliferation of breast and endometrial cells,is considered a promoter for breast and endometrial cancers.Prolonged exposure to estrogen,as in women with early menarche and late menopause,increases the risk of breast cancer.Likewise,long-term use of estrogen replacement without progesterone supplementation for menopausal symptoms increases a woman's risk of endometrial cancer.Progesterone may play a protective role,counteracting estrogen's stimulatory effects.
The male sex hormones stimulate the growth of prostatic tissue.However,research fails to show an increased risk of prostatic cancer in men who take exogenous androgens.
Diet
Numerous aspects of diet are linked to an increase in cancer,including:
obesity (in women only,possibly related to production of estrogen by fatty tissue),which is linked to a suspected increased risk of endometrial cancer
high consumption of dietary fat (due to an increase in free radical formation),which is linked to endometrial,breast,prostatic,ovarian,and rectal cancers
high consumption of smoked foods and salted fish or meats and foods containing nitrites,which may be linked to gastric cancer
naturally occurring carcinogens (such as hydrazines and aflatoxin) in foods,which are linked to liver cancer
carcinogens produced by microorganisms stored in foods,which are linked to stomach cancer
diet low in fiber (which slows transport through the gut),which is linked to colorectal cancer.
ACS GUIDELINES:DIET,NUTRITION,AND CANCER PREVENTION
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Because of the numerous aspects of diet and nutrition that may contribute to the development of cancer,the American Cancer Society (ACS) has developed a list of guidelines to reduce cancer risk in persons ages 2 years and older.
Choose most of the foods you eat from plant sources.
篓C Eat 5 or more servings of fruits and vegetables each day.
篓C Eat other foods from plant sources such as breads,cereals,grain products,rice,pasta,or beans several times each day.
Limit your intake of high-fat foods,particularly from animal sources.
篓C Choose foods low in fat.
篓C Limit consumption of meats,especially high-fat meats.
Be physically active and achieve and maintain a healthy weight.
篓C Be at least moderately active for 30 minutes or more on most days of the week.
篓C Stay within your healthy weight range.
Limit your consumption of alcoholic beverages,if you drink at all.
The American Cancer Society (ACS) has developed specific nutritional guidelines for cancer prevention.