Nutrition Flashcards
What are nutrients?
A chemical element or compound used in an organism’s metabolism or physiology.
How are nutrients classified?
Classification is based on the chemical structure or function of the respective nutrient.
1. carbs
2. proteins
3. lipids
4. vitamins
5. minerals
6. water
Discuss water as a nutrient.
Water comprises a major portion of plants and animals.
Functions:
solvent and lubricant
nutrient transportation and waste transport
thermoregulation
cushioning organs, use in chemical reactions
What are some sources of water as a nutrient?
drinking water, feed, chemical/metabolic processes that produce water
What are some effects of excessive loss of water?
5% loss: disruption of body functions
15%-20% loss: death
Discuss carbohydrates and their structure as a nutrient.
Carbohydrates have the general formula of (CH2O)n or Cn(H2O)n-1
some examples are glucose and sucrose
Carbon and oxygen are almost always the same number or within one of each other in carbs
What are the functions of carbs?
In plants:
a. primary structural component of plant cells
b. energy storage
In animals:
A major source of dietary energy (nonruminants: starches, ruminants: cellulose)
What are some simple sugars?
Most carbs are primarily glucose or polymers of glucose.
- Simple sugars
a. monosacchardies - 1 sugar molecule
ex. pentoses and hexoses
b. Disaccharides - 2 sugar molecule
ex.
cellobiose - glucose, glucose
lactose - glucose, galactose
maltose - glucose, glucose
sucrose - glucose, fructose
What are complex sugars?
Complex sugars are polysaccharides composed of numerous sugars.
a) linkages
If sugars are bound 1,4 - they are linear (ex. amylose, amylopectin, and cellulose)
If sugars are bound 1,6 - they are branced (ex. amylopectin)
Describe some examples of complex sugars.
- Starch
a. amylose - linear component (1,4 linkages)
b. amylopectin - branched component (1,6 linkages) - Hemicellulose: a mixture of pentoses and hexoses that is less digestible than starch, but more digestible than cellulose
- Cellulose: a major constituent of cell walls
has linear chains bound together and is not digested by most animals (somewhat digested by ruminants, but not by monogastrics)
What is lignin?
Lignin is a compound (not a carbohydrate) produced by plants as they mature. Lignin replaces cellulose in the plant as it ages. It is only digestible by fungus.
Lignin is found in overly mature, poor quality feeds.
What are proteins in terms of nutrients?
Proteins are a group of closely related compounds (polymers of amino acids) but each one is physiologically distinct.
They contain carbon, hydrogen, oxygen, and nitrogen.
Protein is also a structural component of animal cells.
What are the uses of proteins?
Proteins build and repair bodily tissues.
The comprise enzymes and hormones.
They comprise antibodies and immunoglobulins.
They make up protective layers like hair and nails.
Compare quantity/quality of protein between plants and animals.
Animals have a more uniform protein character, while plants have a more variable one depending on the plant.
What is crude protein?
This is the relative estimate of a feed’s protein. It can be estimated if the N content is known.
(16% N by weight; N x 6.25% = %CP)
ex.
If a feed is 2% N, then 2 x 6.25% = 12.5 %CP
What are amino acids?
Amino acids are the organic compounds that comprise proteins by being linked together through peptide bonds. There are more than 20 amino acids.
What are non-essential amino acids?
These are amino acids that can be synthesized by an organism at a rate equal to its physiological needs. They are not considered in diet.
What are essential amino acids?
These are amino acids that cannot be synthesized by an organism at a rate equal to its physiological needs. Therefore, they must be included in the ration (diet). There are 10 essential amino acids that can be remembered through the acronym PVT MAT HILL.
PVT
Phenylalanine
Valine
Threonine
MAT
Methionine
Arginine
Tryptophan
HILL
Histidine
Isoleucine
Leucine
Lysine
What are the most common deficient amino acids for animals?
Lysine in corn based diets and methionine in soybean products.
What is the limiting amino acid?
An essential amino acid present in the diet in an amount less than required by the animal.
How many essential amino acids do ruminants require?
0, except for in high producing animals.
This contrasts with monogastrics like white rats (10), swine (10), and chickens (11-13)
What are some effects of protein deficiency?
lower birth/growth rates
reduced production
lower fertility
What are the effects of excess protein in the diet?
Enlarged kidneys (must work to expel excess N as urea)
It is expensive to maintain high protein diets
What is Non-Protein Nitrogen (NPN)
Nitrogen in a feed that is not incorporated in protein molecules
How are NPNs useful?
In ruminants, NPNs are useful because they can use small amounts on NPN to combine it with carbs to make proteins.
In monogastrics, NPNs are not useful, and are possibly toxic.
What is the most common NPN?
Urea is the most common form. It is a commercial N source that contains 40%-45% N.
Describe lipids as a nutrient
Lipids are composed of carbon, hydrogen, and oxygen.
They have potential for large amounts of energy - 2.25 times that of carbs or proteins. This is due to the fact that lipids contain more carbon atoms per oxygen.
Lipids are primarily found as fats or oils, with triglycerides being the most common overall.
What is the fatty acid composition of plants by percent?
15% saturated
85% unsaturated
What are the essential fatty acids for animals?
Linoleic, linolenic, arachidonic
What are the functions of lipids?
- energy source (most concentrated)
- absorb the fat soluble vitamins (A,D,E,K)
- cushion and protect organs
- component of cell membranes (phospholipids)
- reduce dustiness in rations
- provide marbling in meat
Describe minerals as nutrients
Minerals are inorganic elements of the earth.
The major (macro) minerals include: Ca, P, Na, K, Mg, S, Cl
The trace (micro) minerals include: Cu, Fe, Mn, Co, I, Mo, Se
What are the functions of minerals in the body?
- serve as cofactors
- structural components (bones, teeth, etc.)
- electrolyte balance
- parts of organic compounds (ex. thyroid hormones)
What are cofactors?
Cofactors are minerals that act as part of the substrate during the chemical reaction. They help the enzyme perform the reaction before exiting the reaction.
What are rickets and metabolic bone disease examples of?
Diseases caused by Ca deficiency
What are anemia and smaller sizes in young animals associated with?
Fe deficiency
What is goiter and what is it caused by?
Goiter is the irregular growth of the thyroid gland, and it is caused by an I deficiency
What can be caused by an excess of Cu?
liver damage
What can be caused by an excess of F in the body?
soft teeth and bones
Why is Se important?
Se is important because it couples with Vitamin E to work for the immune system. The amount of Se an animal gets depends on the quality of grass available to it.
Describe vitamins as nutrients
Vitamins are organic compounds dissimilar in structure but required in extremely small amounts for proper bodily function.
Vitamins are vital amines - that is, they contain N
The fat soluble vitamins are A, D, E, K
Water soluble vitamins are the B complex and C
What are the main functions of vitamins in the body?
Vitamins serve as coenzymes that assist enzymes in catalytic reactions.
Sources of Vitamin A?
green forages, liver
Sources of B complex vitamins?
green forages, animal products/byproducts, milk products
Sources of Vitamin D?
exposure to sunlight
Sources of Vitamin E?
whole grains
Which vitamins are less important and not usually needed in feeds?
Vitamins C and K
What is energy?
The capacity to do work, and it is a property of nutrients
Energy is expressed as calories, kcals, megacals
Besides water, energy is the most important item in an animals diet.
What are dietary sources of energy?
carbs, fats, proteins
What are the uses of energy?
- maintenance of normal body functions
- reproduction
- growth (formation of wool, muscle, etc.)
- production (eggs, milk)
- work
Which dietary source do we prefer energy to come from and why?
We prefer that energy comes from carbohydrates or fats because we want protein to be directed to other bodily functions.
Classify carbs by function (E=energy, S= structure, R = regulation)
E
Classify lipids by function (E, S, or R)
E, (S)
Classify proteins by function
S, (E), R
Classify minerals by function
S, R
Classify vitamins by function
R
Classify water by function
S, R
What are the functions of Vitamin A?
maintaining vision; essential for maintenance of epithelial linings; cellular metabolism
What are symptoms of Vitamin A deficiency?
night blindness; keratization of epithelium; retarded growth
What are the functions of Vitamin D?
calcium/phosphorous absorption and metabolism
What are symptoms of Vitamin D deficiency?
bone disorders; rickets
What are the functions of Vitamin E?
antioxidant; reproductive functions in some species; helps with absorption of selenium (Se)
What are symptoms of Vitamin E deficiency?
white muscle disease; possible infertility in some species
What are the functions of Vitamin K?
blood clotting
What are symptoms of Vitamin K deficiency?
increased hemorrhaging or longer clotting times
What are some of the B-complex vitamins?
B1- Thiamine
B2- Riboflavin
Pantothenic Acid
Niacin
B6-Pyroxidine
Biotin
Folic Acid
B12-Cyanocobalamin
What are functions of the B-complex Vitamins?
As a group, act as coenzymes in chemical reactions to help release energy, help maintain skin health, help maintain nervous tissue, and help with red blood cell production
Wha are symptoms of B-complex vitamin deficiency?
skin lesions; weakness; paralysis; dermatitis; anemia (lack of B12)
What is the function of calcium?
bone/tooth formation; muscle contraction
What are symptoms of calcium deficiency?
rickets, slow bone development
What are the functions of phosphorous?
bone/tooth formation; enzyme component; part of RNA and DNA
What are symptoms of phosphorous deficiency?
rough hair coat, slow growth
What are the functions of magnesium?
enzyme activator; component of skeletal tissue
What are symptoms of magnesium deficiency?
lowered appetite; hyperirritability; convulsions
What are the functions of sodium?
muscle contractions, maintenance of body fluid levels; electrolyte
What are symptoms of sodium deficiency?
loss of weight; salt craving
What are the functions of potassium?
electrolyte; maintenance of electrolyte balance; enzyme activator
What are symptoms of potassium deficiency?
reduced appetite; heart lesions
What are the functions of chlorine?
electrolyte; acid-base balance; maintenance of osmotic pressure; component of hydrochloric acid
What are symptoms of chlorine deficiency?
reduced appetite; salt craving
What are the functions of sulfur?
synthesis of amino acids in ruminants (component of sulfur-containing amino acids)
What are symptoms of sulfur deficiency?
slow growth; low feed efficiency
What are the functions of iron?
component of hemoglobin
What are the symptoms of iron deficiency?
anemia