Chapter 8 assignment PDF

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Chapter 8 assignment 1. DISCUSS four (4) important functions of Vitamin B6 (2 points) One important function is amino acid metabolism; it plays a critical role in transamination which makes nonessential amino acids, without this all amino acids would be essential because our bodies would not be able to make them in sufficient quantities. Another important role is Heme synthesis, heme is the iron containing protein that transports oxygen in red blood cells; without B6 we would have small red blood cells and inadequate amounts of hemoglobin. B6 also plays a role in carbohydrate metabolism by breaking glycogen into glucose in order to maintain blood glucose levels during exercise and converting amino acids into glucose. B6 also reduces cardiovascular disease by metabolizing methionine into homocysteine which can then be converted into cysteine. Without these conversions and nutrients homocysteine will accumulate in the blood which is associated with cardiovascular disease. 2. According to the World Health Organization, deficiency of which trace mineral is the biggest single cause of preventable brain damage and mental impairment in the world? (1 point) Iodine, women with iodine deficiency’s during pregnancy can result in the child having a mental impairment called cretinism that can stunt growth, and cause deafness and muteness. 3. DEFINE "free radical" and identify three (3) factors that are known to contribute to free radical formation. (2 points) A free radical is a highly unstable atom with unpaired electrons in its outermost shell. During metabolism, oxygen sometimes gains the single electron that was released during oxidation. As a result, the oxygen atom now has an unpaired electron, a free radical. They are formed in physiologic processes when the immune system produces inflammation, exposure to tobacco smoke and other air pollution, ultraviolet rays from the sun, and industrial chemicals. 4. While most fat-soluble vitamins are stored in adipose tissue, 90% of Vitamin A is stored where, making it easy to achieve toxicity? (1 point) 90% is stored in the liver, the remainder is in adipose tissue, kidney and lungs. Toxicity can occur after consuming only 3 to 4 times the RDA, and it can lead to birth defects, blurred vision, hair loss, skin disorders, liver damage, and more. 5. LIST the three active forms of vitamin A found in our bodies and identify the provitamin precursor that is necessary to convert the active form. (1 points) Retinol is the alcohol form, retinal is the aldehyde form, and retinoic acid is the acid form and the collectively are referred to as retinoids. The provitamin Beta-carotene is the precursor that converts retinol into it’s active form. 6. DISCUSS the three (3) primary stages of cancer development in the body. (3 points) The three primary stages of cancer are initiation, promotion, and progression. Initiation is when a cell’s DNA is mutation, the mutation may be random, inherited, or due to environmental factors like UV radiation, tobacco smoke, or certain viruses. The mutated cells may engage in

self repair or self-destruction; self-destruction can lead to promotion, and they may destroy the body’s immune system. Promotion is when the mutated DNA starts to divide, and the mutated DNA is locked into each new cell’s genetic instructions. The enzymes that normally work to repair damaged cells cannot detect the mutation in the DNA so there isn’t an immune response, therefore leading the mutations that can occur for years until there is a detectable mass in the body known as a tumor. Progression is when the cancerous cells grow out of control, they grow their own blood vessels to supply them with oxygen and nutrients and invade surrounding tissues causing the cancer to metastasize through the body. The immune system may be able to detect progression in early stages and destroy them, but if the cells continue to spread it can have detrimental effects on the body....