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