Flashcards in 3a Review of Nutrients 2 Deck (46):
How much water is in the body?
What are the 3 main sources of water?
- drinking water
- water in food
How is water produced in metabolism?
- glucose oxidation
- carbon dioxide and water released
What are the 5 main losses of water?
What are the largest and 2nd largest losses of water?
1. urine (75-85%)
Why do cats produce more concentrated urine?
- originated from desert
- water conservation
What are the 4 main functions of water?
- solvent in which substances are dissolved and transported (ion balance, transport, eliminate waste products)
- necessary for chemical reactions that involve hydrolysis
- regulation of body temperature (evaporative cooling like panting)
- provides shape and resilience to body
What 2 systems regulate the amount of water in the body?
- neural and endocrine
What is dehydration?
lack of water in body tissue
How much water loss needs to occur to be thirsty?
What is water intoxication called?
What happens to body cells during dehydration?
- cells shrink and die
What are the 6 main things that define a vitamin
- required in very small amounts
- not metabolic fuels or structural nutrients
- involved in fundamental functions of the body
- regulators of reactions (catalysts)
- absence must cause a deficiency syndrome
- not synthesized in sufficient quantities to support normal physiologic function
How many water and fat soluble vitamins are there in humans?
- 10 water soluble
- 4 fat soluble
What vitamin is essential in only in primates, guinea pigs and fish?
How many fat and water soluble vitamins are there for dogs?
- 3 fat soluble (ADE)
- 8 water soluble
How many water and fat soluble vitamins are there in cats?
- 4 fat soluble (ADEK)
- 9 water soluble
What are some examples of water soluble vitamins?
- folic acid
- ascorbic acid
What water soluble vitamin is not needed by dogs or cats?
What water soluble vitamin is not required by dog, but required by cat?
What are some physiological functions of vitamins and which vitamin?
- co factors in enzymatic reactions (B)
- DNA synthesis (folacin)
- bone development (D)
- Ca homeostasis (D)
- eye function (A)
- cell membrane integrity (E and C)
- blood clotting (K)
- free radical scavenging (E and B12)
- amino acid and protein metabolism (niacin)
- nerve impulse transduction (choline)
What are some important vitamin interactions?
- critical pathways require concerted action of several B complex vitamins (deficiency of one compromises efficiency of other 3)
- multiple vitamin deficiencies more frequent than single vitamin defences
How are fat soluble vitamins absorbed?
- require bile salts and fat to form micelles for absorption
- passively absorbed, mainly in duodenum and ileum
- transported in conjunction with chylomicrons to liver via lymph system
How are water soluble vitamins absorbed?
- active transport
- some require carrier protein called intrinsic factor
- sodium dependent, carrier mediated absorption pump
How are vitamins generally provided in the diet?
- vitamin premix
- organ meat rich in fat soluble vitamin
What is a provitamin?
- compound that requires an activation step before it becomes biologically active
What is an example of a provitamin?
- beta carotene cleaved by enzymatic processes releases 2 molecules of retinol
- cats need to be provided retinol as they do not have the enzymatic path
What is a vitamer?
- chemically the same compound as a vitamin
- may exert varying physiologic effects because it is an isomer
- e.g. alpha tocopherol vs gamma tocopherol
What is a stereoisomer
- differ in arrangement of groups around stereocenters
- RRR-alpha tocopherol is most biologically active
What is a vitamin like substance?
- exhibit properties similar to vitamins
- have physiologic functionality but questionable essentiality (conditionally essential)
- L carnitine
What are minerals?
inorganic elemental atoms that are essential nutrients
How many mineral elements are essential for mammals?
greater than 18
What are some macro minerals and how much per kg of diet needed?
- Ca, P, K, Na, Cl, Mg, S
What are some trace elements and how much per kg of diet needed?
- Fe, Zn, Cu, Mn, Co, Mb, F, Se, I, Cr
What are some ultra trace elements and how much per kg of diet needed?
- Mo, As, B, Ni, Si, V
What are the 3 main functions of minerals?
- structural components of body organs and tissues
- constituents of body fluids and tissues (electrolytes)
- catalysts/cofactors in enzyme and hormone systems
What are 3 methods of mineral homeostatic regulation?
- maintaining of mineral concentrations at active sites in narrow physiologic limits despite over or under ingestion
- control of intestinal absorption and excretion
- urinary excretion
What are 5 factors that influence mineral bioavailability?
- chemical form (mineral solubility)
- other dietary components that interact metabolically
- age, gender and species of animal
- intake of mineral and the need (body stores)
- environmental factors (organic versus inorganic minerals)
Are meat derived or plant derived minerals for available? why?
- meat more available
- physic acid in plant tissues are bound to minerals and cannot be released
What are some sources of Ca?
bone, meat meals, inorganic sources
What are some sources of phosphorous?
- meat, oil seeds, grains, inorganic sources
What are some sources of magnesium?
- meat meal, oilseeds, grains, inorganic sources
What are some sources of trace elements?
Are trace element sulphites, chlorides, carbonates or oxides most available?
- sulfate, chloride > carbonates > oxides
What is the 'meat factor'?
- provides an available form of mineral
- enhances absorption of the mineral supplied by the rest of the food