Food- Audio SAQs.docx

**[Questions:]** - What are nutrients? Nutrients are the chemical substances present in food that are used by organisms. - What are two reasons why nutrients are necessary? For energy, and for growth - Name the six elements present in food. Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus,...

**[Questions:]** - What are nutrients? Nutrients are the chemical substances present in food that are used by organisms. - What are two reasons why nutrients are necessary? For energy, and for growth - Name the six elements present in food. Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur - What is a trace element? An element needed in small amounts - Give an example of a trace element. Iron - What are the five major types of biomolecules found in food? Carbohydrates, Lipids, Protein, Vitamins and water - Name the three elements found in carbohydrates.  Carbon, Hydrogen, Oxygen - In what ratio are these elements usually present? Cx(H20)y - What are monosaccharides? A single sugar unit - Give an example of a monosaccharide. Glucose - What are disaccharides? Two sugar units joined together - Give an example of a disaccharide. Sucrose - What are polysaccharides? Many sugar units - Give an example of a polysaccharide. Starch - Name three sources of carbohydrates. Bread, rice, pasta - Give a structural role of carbohydrates. Cellulose is used to form plant cell walls - Give a metabolic role of carbohydrates.  Carbohydrates can be broken down in respiration to release energy.  - Name the three elements found in lipids. Carbon, Hydrogen, Oxygen - Distinguish between fats and oils. Fats are solid at room temperature, oils are liquid at room temperature. - How do carbohydrates differ from lipids in chemical composition? Carbohydrates have a fixed ratio for their elements, lipids have no fixed ratio.  - What is the structure of the most basic form of a lipid? A triglyceride. A glycerol molecule and three fatty acids. - Distinguish between triglycerides and phospholipids. Phospholipids have a phosphate group, triglycerides do not. - Name two sources of lipids. Butter, oil - Give a structural role of lipids. Phospholipids are important structures in the cell membrane. - Give a metabolic role of lipids. Provide energy - Name the elements present in proteins. Carbon, hydrogen, oxygen, nitrogen - Name two elements sometimes present in proteins. Phosphorus, Sulfur - What are proteins composed of? Amino acids - Give two sources of protein. Milk, meat - Give a structural role of proteins. Keratin is found in hair - Give a metabolic role of proteins. Enzymes, which are proteins, control chemical reactions - Give an example of a water-soluble vitamin. Vitamin C - Give a deficiency disorder of vitamin C. Scurvy - Give an example of a fat-soluble vitamin. Vitamin D - Give a deficiency disorder of vitamin D. Ricketts - Name two minerals needed by plants and a function of these minerals. Ca (Calcium) is used to make strong cell walls. Mg (Magnesium) is required to make the pigment chlorophyll. - Name two minerals needed by animals and a function of these minerals. Ca (Calcium) used to make strong bones and teeth. Fe (Iron) required to make haemoglobin. - Give two uses of water for living things. It is a good solvent. It makes up the bulk volume of body fluids. - What percentage of cell contents does water make up? 70-95% **Qualitative Food Test Questions:** 1. What reagents or chemicals did you use to test for the presence of protein.  Biuret reagent 2. What colour indicates the presence of protein in a sample? Lilac 3. State a use of Benedict's solution in the laboratory. To test for the presence of a reducing sugar 4. Why was the brown paper used to test for starch allowed to dry out? To make sure that the stain was from the lipid used and not just water.  5. What food test required the use of heat? Testing for a reducing sugar 6. What was the colour of the contents of the control tube after the test for a reducing sugar? A brick-red colour 7. What food biomolecule may be identified using Benedict's solution? A reducing sugar 8. What type of food may be identified in the laboratory using brown paper? A lipid 9. In relation to a test for reducing sugar, which of the following is correct? No heat needed/ heat but do not boil/ boil? Heat but do not boil 10. What is the control used when carrying out these tests? Water 11\. A screenshot of a phone Description automatically generated Protein- chicken Fat- butter Sugar-cake Starch-pasta 12. Name a chemical element found in proteins that is not found in carbohydrates. Nitrogen