Lysine is used in biosynthesis of proteins and contains an α-carboxylic acid group (deprotonated −COO− form under biological conditions), α-amino group (protonated −NH3+ form under biological conditions), and a side chain lysyl ((CH2)4NH2) which is classified as a basic, charged aliphatic amino acid. It is encoded by codons AAG and AAA. Similar to other amino acids, α-carbon is chiral and lysine which refers to either enantiomer or racemic mixture of both. Lysine could not be synthesize by human body so it is essential in humans and should be obtained from diet. In organisms which synthesize lysine have two main biosynthetic…
Author: Emily
Leucine is an essential amino acid which is used in protein biosynthesis. It is an amino acid which contains α-amino group (protonated −NH3+ form under biological conditions), a side chain isobutyl group (making a non-polar aliphatic amino acid) and α-carboxylic acid group (deprotonated −COO− form under biological conditions). It is a prerequisite in humans as the body could not synthesize, it should be obtained from diet. The dietary sources are foods which contains protein such dairy products, meats, beans, soy products and other legumes. It is encoded by codon UUA, CUU, UUG, CUA, CUC, and CUG. Similar to isoleucine and…
Isoleucine symbolizing Ile or I, is an α-amino acid which is used in biosynthesis of proteins. It encloses an α-carboxylic acid group (which is in deprotonated −COO− form under biological conditions), an α-amino group (which is in protonated −NH+3 form under biological conditions and a hydrocarbon side chain classified as a non-polar, uncharged and aliphatic amino acid. It is crucial in humans as the body cannot synthesize it and should be obtained from diet. It is synthesized from pyruvate employing leucine biosynthesis enzymes in other organisms such as bacteria. It is encrypted by codons ATC, ATT and ATA. Isoleucine is…
Threonine with symbol T or Thr, is an amino acid which is used in biosynthesis of proteins. It encloses a α-amino group, a carboxyl group and a side chain which contains a hydroxyl group making it a polar or uncharged amino acid. It is fundamental in humans which mean the body cannot synthesize it so it should be obtained from the diet. It is synthesized from aspartate in bacteria such as E. coli. It is encrypted by all the codons starting AC (ACT, ACA, ACC and ACG). It is an amino acid which is common in various proteins and together…
Tryptophan is an essential amino acid and is an integral part of dietary protein. Tryptophan, an amino acid present in some foods, can be converted to niacin in the body. It is an essential amino acid which serves various substantial purposes such as nitrogen balance in adults and growth in infants. It forms niacin which is crucial for formation of neurotransmitter serotonin. Tryptophan is of two types such as D-tryptophan and L-tryptophan. It is used in biosynthesis of proteins. It contains a α-carboxylic acid group, α-amino group and a side chain indole which makes it a non-polar aromatic amino acid.…
Sucrose is a disaccharide composed of one unit of glucose and one unit of fructose. It is digested by the enzyme sucrase, which is located on the absorptive surface of the small intestine. Sucrose is found in several fruits and vegetables and is present in large quantities in sugar beet and sugar cane – from which it is extracted and purified on a vast industrial scale. Sucrose is readily available in highly purified or partly purified forms (e.g. white sugar, brown sugar, treacle or syrup). It is also very widely used by food processors to sweeten, preserve and texturize a…
Many children have a preference for sweet, carbohydrate-rich foods. Overconsumption of foods high in sugar may increase risk of dental caries and obesity. However, rigorous elimination of sugar-containing foods from a child’s diet without adequate energy substitution may lead to weight loss and poor growth. Again, moderation is the key. Decreasing refined-sugar intake during childhood can be difficult, as it is often added to processed foods popular with children. Simple carbohydrates are naturally present as simple sugars in fruits, milk, and other foods. Plant carbohydrates also can be refined to produce sugar products such as table sugar or corn syrup.…
Insoluble fibers are those which do not dissolve in water, do not form gels (are not viscous), and are less readily fermented. Insoluble fibers, such as cellulose, form structures such as the outer layers of whole grains (bran), the strings of celery, the hulls of seeds, and the skins of corn kernels. These fibers retain their shape and rough texture even after hours of cooking. In the body, they aid digestive system by easing elimination. Insoluble fibers are generally found in whole grains, such as wheat, rye, and brown rice, and are found in many vegetables. These fibers are not…
Fiber can be classified by how well it dissolves in water. Most foods contain both types of fiber: soluble and insoluble. When a food is said to be a soluble or insoluble fiber it refers that majority of the fiber present in it is of that kind. The soluble fibers include gums, mucilages, pectin, and some hemicelluloses. They are generally found around and inside plant cells. Soluble fibers dissolve in water. They are also viscous, forming a gel when wet, and fermentable; that is, they are easily digested by bacteria in the colon. Soluble fibers are typically found in citrus…
Fiber isn’t a single nutrient but a family of plant-based nutrients that are generally resistant to human digestion. Plants lack bony skeletal design which provides much of an animal’s shape or form. In general, fibers contribute much of the structural support to cell walls and the plant. Plants also use certain fiber as the foundation for their scar tissue. It is important to remember that while humans and other mammals prefer to produce proteins like collagen as the structural basis of their bodies, plants use carbohydrates. Mostly, fiber as a class is made up of polysaccharides, but fibers vary from…