Answer the following question given this paragraph: The cell body contains the nucleus and other organelles. Q: The cell body contains what central structure along with other organelles? Choices: - neutron - protons - electron - nucleus A:
nucleus
(Question)
Answer the following question given this paragraph: In catalysis, if a molecule forms strong bonds to the catalyst, then the catalyst may become poisoned. Experiments on various catalysts showed the following results: a. Fe, Ru, and Os form weak bonds with N2; however, O2, alkynes, alkenes, CO, H2, and CO2 interact more strongly. CO2 and H2 form weak bonds with a Co or Ni surface. Rh, Pd, Ir, and Pt form weak bonds with H2 but do not bond with CO2. Cu, Ag, and Au form weak bonds with CO and ethylene. Explain why Fe was chosen as a catalyst to convert nitrogen and hydrogen to ammonia. Why is Fe more suitable than Ru or Os? f. Because alkenes generally interact more strongly with metal surfaces than does H 2, what catalyst would you choose for hydrogenation of an alkene such as ethylene? g. Although platinum is used in catalytic converters for automobile exhaust, it was not found to be a particularly effective catalyst for the reaction of H2 with a mixture of carbon monoxide and carbon dioxide to produce methane. Why? h. If you were interested in developing a catalyst to reversibly bind ethylene, which of the catalysts listed here would you choose? 14. Nonstoichiometric metal oxides can be effective catalysts for oxidationreduction reactions. One such catalyst is Ni1xO, found to be effective for converting CO to CO2when oxygen is present. Why is it so effective? 15. The chemical reactions in an organism can be controlled by regulating the activity of certain enzymes. Efficient regulation results in an enzyme being active only when it is needed. For example, if a cell needed. Q: What happens if a molecule forms strong bonds to the catalyst? Choices: - molecules gets poisoned - surface gets poisoned - membrane gets poisoned - catalyst gets poisoned A:
(Answer)
catalyst gets poisoned
Ques: Answer the following question given this paragraph: Figure 15.2 All animals that derive energy from food are heterotrophs. The (a) black bear is an omnivore, eating both plants and animals. The (b) heartworm Dirofilaria immitis is a parasite that derives energy from its hosts. It spends its larval stage in mosquitos and its adult stage infesting the hearts of dogs and other mammals, as shown here. (credit a: modification of work by USDA Forest Service; credit b: modification of work by Clyde Robinson). Q: All animals that derive energy from food are classified as what? Choices: - lifeforms - paleotrophs - heliotrophs - heterotrophs A:
Ans: heterotrophs
(Q).
Answer the following question given this paragraph: Longer chains of monosaccharides are referred to as polysaccharides . Starch, glycogen, and cellulose are three extremely common polysaccharides made entirely out of glucose molecules. The differences lie in the types of bonds between the glucose units and the extent of branching in the carbohydrate chain. Starch is found in plants and is consumed as part of our diet. Glycogen is made by the body and is a storage form of glucose for when the cells need extra energy. Cellulose is another long-chain polysaccharide found in plants. Unlike starch and glycogen, the human body cannot break cellulose down into molecules of glucose. Although cellulose does not have any nutritional value in terms of calories, it is a major component of dietary fiber, which has other digestive benefits. Q: What is the term for longer chains of monosaccharides ? Choices: - proteins - hydrocarbons - oligosaccharides - polysaccharides A:
(A).
polysaccharides
Ques:Answer the following question given this paragraph: CHAPTER SUMMARY 45.1 Population Demography Populations are individuals of a species that live in a particular habitat. Ecologists measure characteristics of populations: size, density, dispersion pattern, age structure, and sex ratio. Life tables are useful to calculate life expectancies of individual population members. Survivorship curves show the number of individuals surviving at each age interval plotted versus time. Q: What is the term for individuals of a species that live in a particular habitat? Choices: - family - ecosystem - biosphere - population A:

Ans:population
Answer the following question given this paragraph: Digestion of Carbohydrates Carbohydrate digestion begins in the mouth (Figure 20.5 "The Principal Events and Sites of Carbohydrate Digestion"), where salivary -amylase attacks the -glycosidic linkages in starch, the main carbohydrate ingested by humans. Cleavage of the glycosidic linkages produces a mixture of dextrins, maltose, and glucose. (For more information about carbohydrates, see Chapter 16 "Carbohydrates". ) The -amylase mixed into the food remains active as the food passes through the esophagus, but it is rapidly inactivated in the acidic environment of the stomach. Figure 20.5 The Principal Events and Sites of Carbohydrate Digestion. Q: Where does carbohydrate digestion begin in the body? Choices: - stomach - intestines - throat - mouth A:
mouth