Lessons+2.4.5.6

Read 2.4 Carbohydrates 2.5 Lipids 2.6 Proteins Answer the following questions... 1. What is the usual function of various carbohydrates in humans? The most important function of carbohydrates is to provide short-term, quick energy. 2. What is the difference between a simple carbohydrate and a complex carbohydrate? DESCRIBE EXAMPLES A simple carbohydrate has a low amount of carbon atoms (three to seven) in its make up. They are also known as monosaccharides. One example is a pentose, or a five-carbon sugar. On the other hand, complex carbohydrates have more than seven carbon atoms in their make ups. They are known as polysaccharides. Starch and glycogen are complex carbohydrates; they have many glucose units. 3. What is starch? What is the source of starch? Starch is a stored form of glucose. It releases insulin from the pancreas to promote the storage of energy. 4. What is "fiber" and of what benefit is it in the diet? Fiber foods such as beans, nuts, fruits, and vegetables, are non digestible. This means that that only the energy is taken from the food and all else is a catalyst to the intestine. High fiber diets can help prevent heart disease and cancer. 5. Why does low-carb dieting work sometimes? But what are the risks? Low carb dieting is effective in a short amount of time because the body has less to store as energy and instead burns up all protein you eat. This can cause arteries to clog, as well as heart disease. Low-carb means high fat. High fat is worse for your body that storing carbohydrates. 6. What is the function of fats and oils? DESCRIBE EXAMPLES Fats and oils are used for long-term energy. Fats such as lard or butter are saturated meaning they have no double bonds between carbon atoms. Oils such as cooking oils are liquid at room temperature. Often these liquids are fatty acids meaning they have 16 or 18 carbon atoms per molecule. 7. What are fats and oils composed of? They are composed of one glycerol and three fatty acids. 8. What is the difference between a saturated and unsaturated fat? DESCRIBE EXAMPLES Saturated fats such as butter have no double bonds between the carbon atoms; the chain is saturated with hydrogens. Unsaturated fats such as olive oils have double bonds in the carbon chain causing less hydrogens in the molecule. 9. What are the uses of phospholipids in the body? DESCRIBE EXAMPLES Phospholipids are used mostly as cellular membranes. They form a double layer of molecules with the head facing the cell and the outer cytoplasm of the body while the tails of both layers face each other. 10. What are the uses of steroids in the body? DESCRIBE EXAMPLES Steroids are lipids that increase levels of cholesterol, testosterone, and/ or estrogen. 11. Why do we need fat in our diet? DESCRIBE EXAMPLES Fat is vital to our diet because it is the main source of life: protein. Proteins are in charge of important functions such as muscle contraction fueling all movement, and sending messages within the body. 12. What are the major functions of proteins in organisms? DESCRIBE EXAMPLES Proteins are hair, as well as cell membranes, messengers, muscles, enzymes, and hormones. Most importantly proteins are a large part of antibodies, part of the immune system. 13. What is the subunit of a protein? How do they get their name? Amino acids are subunits of proteins made up of one acid group and one amino group hence the name, amino acid. 14. How does the shape of a protein relate to its function? DESCRIBE EXAMPLES The shape of a protein determines its function within the organism. If the shape is changed by denaturation, it can no longer function correctly. For example, when an egg is heated it curdles and can not be returned to a functioning state.