Digestion begin

CUESTIONARIOS

24 HOURS

1. According to the article, where does digestion begin?

 in our brain

2. What are the four main parts of the digestive system?

 absorption and elimination, Ingestion, digestion,

3. What role do enzymes play in digestion?

 In the saliva, it chemically break down food into form the body can use.

4. What is a chemical catalyst?

 They are enzymes; chemical compounds that speed up the rate of a chemical reaction without being consumed by the reaction.

5. What term is applied to food traveling down the esophagus?

 The food travels down the throat, which leads into the esophagus and into the stomach.

6. What is the primary role of stomach acid indigestion?

 The stomach secretes juice that converts food into a liquid – like- sub- stance known as chime.

7. In what part of the body is most food actually absorbed into the blood stream?

 In the intestines

RECYCLING ALUMINUM

1. List the three steps involved in recycling aluminum in Dharavi.

 The trash of the aluminum products is recollected.

 The cans are flooded in acid, to clean the designs and brand names are removed.

 The cans are crushed and melted in a furnace.

2. What fuel does Muktar use in his furnace?

 Coal powered furnace

3. How is he able to obtain the high temperatures needed to melt the aluminum?

 The furnace is filled with coal witch is ignited and stoked to produce temperatures exceeding.

4. What makes aluminum recycling profitable?

 Extracting this metal from aluminum ore is expensive, it pollutes the environment, and it consumes an amount of energy.

5. Describe the three-step Bayer process, by which aluminum oxide is purified from bauxite.

 First bauxite is dissolve in a solution of sodium hydroxide. Sodium aluminate forms the chemical reaction of aluminum oxide eighth sodium hydroxide and H2O. As follows: Al2O3 + 2NaOH + 3 H2O  2NaAl(OH)4

 Second: Sodium aluminate solution is pumped into a huge tank and, as it cools, the sodium aluminate decomposes into aluminum hydroxide and sodium hydroxide. As follows: NaAl(OH)4  Al(OH)3 + NaOH,

 Third: The aluminum hydroxide is heated, which forms aluminum oxide, as follows: 2Al(OH)3  Al2O3 + 3 H2O The aluminum is then produced from the aluminum oxide.

6. What happens next to the aluminum oxide?

 The oxide of the aluminum turns into oxygen.

7. Describe the two advantages aluminum has for recycling.

 It reduces the amount of waste that needs to be buried or burned.

 Is easier because It does nor corrode, unlike other metals.

8. What frequently happens to used plastics,

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