Nutrition Exam 3

What are micronutrients?

Substances that your body needs in smaller quantities

What are the micronutrients?

Vitamins and minerals

What are vitamins?

Organic, naturally occurring molecules

How do we obtain vitamins?

Either through out diet or through synthesis (ex. vitamin d from sunlight exposure)

What are the 2 types of vitamins?

Water soluble and fat soluble

Which vitamins are water soluble?

B and C vitamins

Which vitamins are fat soluble?

A, D, E, and K Vitamins

What are the 4 qualities of water soluble vitamins?

1) available in short term supply 2) low risk of toxicity 3) dissolves in water 4) less stable during processing

What are the 4 qualities fat soluble vitamins?

1) available in long term supply 2) high risk of toxicity 3) dissolves in fat 4) stable during processing

What 5 processing practices can destroy vitamins?

1) heat 2) light exposure 3) air exposure (oxidation) 4) alkaline conditions 5) excess water

What is bioavailbility?

The extent to which a substance is absorbed and utilized by the body.

What are 4 factors that impact bioavailability?

1) age 2) diet 3) illness 4) medication

Vitamins can also function as….

cofactors/coenzymes

What is a cofactor?

An organic molecule that attached to an enzyme, helping to further activate it and increase the speed of the reaction.

What is an example of a vitamin being used as a cofactor?

Vitamin C is a cofactor in collagen synthesis.

How does our body store vitamins?

Our body does not store vitamins.

What causes vitamin toxicity?

Over-supplementation

What is a mineral?

An inorganic molecule

Why are minerals essential micronutrients?

Our bodies are unable to synthesize them

Which foods have the highest bioavailability of nutrients?

animal products

What is unique about minerals in food processing?

They are not destroyed during cooking and digestion

How are minerals mainly lost?

Through sweat

How many macro-minerals should be consumed daily?

more than 100 mg/day

How many micro-minerals should be consumed daily?

less than 100 mg/day

Mineral toxicity is…

rare

Minerals can also act as…

cofactors

Example of minerals acting as cofactors?

magnesium is a cofactor for DNA synthesis

What is fortification?

adding nutrients to foods where they were in small amounts previously

What is a refined grain?

Processing where the bran and germ are removed from whole grains

What is the problem with refined grains?

Nutritional value is loss

What diseases are associated with mineral deficiencies.

Beriberi and Pellagra

What deficiency causes Beriberi and what are the symptoms?

Vitamin B1; cardiac, neurological, and infantile symptoms

What deficiency causes Pellagra and what are the symptoms?

Vitamin B3; dry, scaly plaques

What is enrichment?

Replacing nutrients lost during food processing

What specific ingredient is enriched to prevent nutrient deficiencies?

Flour

What 3 micronutrients are important for energy production?

Thiamin, riboflavin, niacin

These 3 micronutrients function as…

coenzymes in the TCA cycle

What is the active form of an enzyme called?

Holo-enzyme

What is the protein part of the enzyme called?

Apoenzyme

What is another name for vitamin A?

Retinoids

What are the 3 forms of vitamin A?

retinol, retinal, retinoic acid

What provitamins can be converted to retinol in the intestine?

carotenoids

What 2 roles does vitamin A play in vision

1) maintains the cornea 2) converts light energy into nerve impulses at the retina

The retina consists of…

cones and rod

Cones help you see…

color

Rods helps you see…

black and white

What molecules in the rods convert light into nerve signals?

rhodopsin

What is an antioxidant?

a compound that readily gives up electrons to other substances

What are free radicals?

unstable molecules that steal electrons, causing structural damage

What do antioxidants do for free radicals?

donate electrons to stabilize them

Which vitamins act as antioxidants?

Vitamins C & E

What impacts the bioavailability of vitamin c?

food processing: excess heat, oxygen exposure, pH changes

What percent of the body is water?

65%

What are 3 main functions of water?

1) transports nutrients and waste products

2) acts as a solvent

3) maintains blood volume

What are the 2 major fluid compartments in the body?

Intracellular and extracellular fluid

Which fluid compartment holds the most water?

Intracellular

What are electrolytes?

salts that dissociate into ions when dissolved in water

What are positively charged ions?

cations

What are negatively charged ions?

anions

Is the concentration of potassium higher inside or outside the cell.

inside the cell

Is the concentration of sodium and chloride higher inside or outside the cell.

outside the cell

How does water move across cells?

passive transport, specifically through osmosis

How do ions move across cells

active transport

What is fluid balance?

water gained = water lost

What 3 factors regulate fluid balance?

1) fluid intake

2) hormones

3) sodium intake

What are the primary hormones that regulate fluid and electrolyte balance.

antidiuretic hormone (ADH), aldosterone, natriuretic peptides

What does ADH do? What stimulates its release and what produces it?

promotes water retention by the kidneys after excessive water loss is detected, produced by the hypothalamus.

What is the role of aldosterone? what stimulates its release and what

retains plasma sodium when blood pressure drops, released by the kidney

What is role of a natriuretic peptides? what triggers it’s release and where is it released from?

blocks the release of ADH and aldosterone, preventing excretion of water and sodium. triggered by excessive water and sodium loss through urination, secreted by the heart.