1. Name three kinds or types of nutrients. One type of a nutrient is a carbohydrate. Sugar is a carbohydrate. Two other nutrient types are fats and proteins. Butter is a fat and lean meat is a good source of protein. 2. Of what chemical elements are carbohydrates composed? One chemical that makes up carbohydrates is carbon. Two other elements are oxygen and hydrogen. In carbohydrates, there are always two hydrogen atoms for every oxygen atom; in other words, carbohydrates are carbon mixed with water. 3. How can you test for the presence of starch? You can test for starch by dripping iodine on it. Iodine turns starch blue. 4. Why do physicians test urine with Benedict's solution? Physicians use this test because they are looking for glucose. This method is highly reliable due to its sensitiveness. 5. How are the following products tested for fat content: butter, peanut butter, lard, codliver oil, castor oil? The items are tested for oil by smashing them against a paper. If a transparent spot forms, then there is fat in the item tested. 6. Why are beans or eggs often substituted for meat in a meal? Eggs and beans are another good source protein. Vegetarians prefer meatless sources of protein such as these. 7. What elements enter into the composition of proteins? The most common elements found in proteins are oxygen, hydrogen, carbon, and nitrogen. Many proteins also contain sulfur and/or phosphorus, and occasionally other elements such as iron. 8. The carbon in coal was once part of the air. Explain. Plants use the carbon in the carbon dioxide, which is in the air to create starch. Coal is made from dead plant matter. The carbon gets preserved inside the plant. 9. What is meant by a catalyst? A catalyst is a substance that is not changed by the chemical reaction it creates. Chlorophyll is an example of a catalyst. 10. Contrast photosynthesis and respiration. During photosynthesis, oxygen is produced as a waste product. During respiration, it gets breathed back in, and carbon dioxide is produced as a waste product.