Ch 7-10 + D Flashcards
Define the term vitamin and how is it classified
Organic compounds required in small quantities for specific functions in the body. They are a essential(body cannot synthesize)micronutrient. They are not a source of energy. They are already broken down into individual units unlike macronutrients.
Which are fat-soluble vitamins and what are their primary functions
vitamins A, D, E, and K
A-eyesight and cell differentiation(stem cellsbecome progressively specialized for functions unique to tissues)
D-Bone growth and maintenance, cell development, immunity.
E-antioxidant, protects from oxidative damage
K-blood clotting and bone formation
Which are fat-soluble vitamins and what are their primary functions
vitamins A, D, E, and K
A-eyesight and cell differentiation(stem cells become progressively specialized for functions unique to tissues)Except for its role in vision, vitamin A usually functions as a hormone that exerts its effects by controlling the synthesis of numerous proteins encoded by our genes.
D-Bone growth and maintenance, cell development, immunity.
E-antioxidant protects from oxidative damage and helps prevent oxidative changes in low-density lipoproteins (LDLs) that would otherwise increase LDL’s plaque-forming potential; therefore, vitamin E may play a role in reducing plaque formation in blood
K-blood clotting and bone formation.Vit K plays a key role in bone metabolism by modifying bone proteins, which allows them to bind calcium and regulate bone formation
What are the two forms of vitamin A that we can consume? What are the food sources of each form? Which form has the greatest potential for toxicity?
Beta carotene-plant sources greens, carrots, mango, papaya
Preformed vitamin A-liver, oily fish like tuna
Overtaking a supplement of vitamin A can result in bone weakness, birth defects, liver damage
How does vitamin A help with our vision? What is the visual pigment that detects light in our eyes? What is a Vit A deficiency in regards to vision?
Vita A deficiency results in blindness and impared immune system.
Rhodopsin is found in light-sensing cells within the retina at the back of the eye. When rhodopsin absorbs light, retinal changes its shape (from cis to trans configuration)
When vitamin is low,the light-sensing cells are unable to regenerate rhodopsin. This makes it difficult to see in low light “night blindness”
Define free radicals. What are the environmental sources that cause free radicals? What are three things in our body that free radicals can damage?
Free radicals are reactive molecules with unpaired electrons that attempt to pair up with other molecules, atoms, or individual electrons to create a stable state.
Environmental sources-cigarette smoking, air pollution and UV light
Free radicals can damage bacteria, DNA
What do antioxidants do to free radicals? What are the 3 vitamins that have antioxidant properties? Identify good food sources of ea.
Antioxidants protect cells from damage caused by highly unstable molecules called free radicals. Antioxidants donate electrons to free radicals without becoming unstable themselves.
Vitamin A carotenoids,vitamin E,
Which vitamin is known as the sunshine vitamin? explain the activation of vitamin D from sunlight. Which 2 organs play a role in “activating” vitamin D?
D
Inactive Vit D is eaten or synthesized by the skin, it enters circulation and moves to the liver then converted to its active form. The active form(calcitriol) is produced in the kidneys. Conversion of vitamin D to calcitriol in the kidneys is responsible for helping to correct calcium concentrations in the blood.
What are the three ways vitamin D maintains calcium concentrations in the blood?
Calcium is important for muscle contraction and bone remodeling. If blood calcium drops too low-Parathyroid gland releases PTH which travels to the kidney, calcitriol increases calcium uptake from urine, calcitriol increases calcium release from bone. Calcitriol increases absorption of the calcium from the intestines.
Calcitriol also works with parathyroid hormone to decrease calcium excretion by the kidneys and increase its release from bone to raise blood calcium concentrations.
Parathyroid hormone and active vitamin D will decrease total bone calcium.
Why might the maintenance of appropriate blood calcium concentrations be impaired in someone with advanced liver or kidney disease?
The kidneys produce the active form of D
Who is at risk for vitamin D deficiency?
Infants cant get d from breast milk, elderly which have a reduced ability to synthesize vitamin D and tend to stay indoors.
What are two conditions that result from vitamin D deficiency?
Bowed legs/knocked knees-bone diseases
What are good food sources of vitamin K? Why could vitamin K be considered non-essential?
Leafy greens,broccoli,brussel sprouts, kiwi, avocado. There isn’t a RDA or UL for vitamin K.
Which three fat-soluble vitamins play a role in bone health?
A,D,K
Which vitamin fuctions as an antioxidant
provitamin A and vitamin E
Explain the relationship between free radicals and antioxidants
Free radical molecules have unpaired electrons, making them unstable and reactive. The free radical steals an electron from another molecule to stabilize itself. In normal molecules, all electrons are paired. The molecule that lost its electron has been oxidized creating a new free radical. This creates a chain reaction; the newly formed free radical oxidizes another molecule by stealing an electron from it. Antioxidants can donate an electron without becoming unstable and reactive.
What are three ways that water-soluble vitamins differ from fat-soluble ones?
Dissolve in water, Most circulate freely in blood immediately. Not stored in large amounts in tissues, so we need to consume them consistently to maintain levels. water-soluble vitamin toxicity generally does not occur as we eliminate extra through urine.
Which type of vitamin has a greater risk of toxicity?
ULs exist for niacin, vitamin B6, folate, vitamin C, and choline.
What are six possible causes of a vitamin deficiency?
Inadequate intake(poverty, anorexia,illness, excessive alcohol intake) decrease absorption(gut issues, drugs, alcohol), decreased utilization in cells(deficient in other nutrients, infection, drugs, alcohol) Increased requirements(growth pregnancy, chronic illness, infection) Increase breakdown (drugs, alcohol) increased losses and excretion(increased urine, blood loss, ulcers, parasites, infection)
Define coenzyme. The B vitamins function as coenzymes that transform the macronutrients(____,_____ and fat) into ____.
They assist in other types of metabolic reactions also.
a compound that binds to a protein (enzyme) and is required for its function or activity. Coenzymes are not actually part of the enzyme structure; rather, they assist enzymes in carrying out their reactions, often by directly interacting with the reaction substrate (a molecule upon which an enzyme acts). In other words, the B vitamins do not provide energy to the cells, but they play a critical role in energy transformation.
Identify the B vitamins.
thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), cobalamin (B12), and folate (B9)
