1.3.4 . What are hexoses? What are some examples of hexoses with important biological functions?

Hexoses are carbohydrates made up of six carbon atoms. Glucose, fructose and galactose are all examples of hexoses. Hexoses have an important biological role, as they are energy sources for the metabolism. The aldohexoses have four chiral centres for a total of 16 possible aldohexose stereoisomers (24). The D/L configuration is based on the orientation of the hydroxyl at position 5, and does not refer to the direction of optical activity. In bio-organic chemistry, a hexose is a monosaccharide with six carbon atoms, having the chemical formula C6H12O6. Hexoses are classified by functional group, with aldohexoses having an aldehyde at position 1, and ketohexoses having a ketone at position 2.

1.3.5. Make use of vitamins b,а biological role and of the reaction of vitamins b

Group of 7 water soluble vitamins, thiamin, riboflavin, niacin, pyridoxine, cobalamin, biotin & pantothenic acid. Biotin & pantothenic acid deficiencies are extremely rare coz it is found in numerous foods and also is synthesized by intestinal bacteria. Biotin deficiency may occur with prolonged antibiotic therapy & ingestion of raw eggs.

Other Names: Vitamin B1 Thiamin RDA: Men: 1.2 mg/dayWomen: 1.1 mg/day

Function: Part of coenzyme TPP (thiamin pyrophosphate) used in energy metabolism

Food Sources: ÷Whole-grain, fortified, or enriched grain products ÷Moderate amounts in all nutritious food ÷Pork paddy grains, cereals,meat,yeast,honey, nuts

Destruction: Easily destroyed by heat

Deficiency Disease: Beriberi (wet with edema; dry with muscle wasting)

Deficiency Symptoms (often due to heavy alcohol consumption): ÷Enlarged heart, cardiac failure ÷Muscular weakness ÷Apathy, poor short-term memory, confusion, irritability ÷Anorexia, weight loss

Toxicity Symptoms: None reported

тиамин

1.3.6. Make use of structure of rna features of structure rna?

Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA it is more often found in nature as a single-strand folded onto itself, rather than a paired double-strand. Cellular organisms use messenger RNA(mRNA) to convey genetic information (using the letters G, U, A, and C to denote the nitrogenous bases guanine, uracil, adenine, and cytosine) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome.

Some RNA molecules play an active role within cells by catalyzing biological reactions, controlling gene expression, or sensing and communicating responses to cellular signals. One of these active processes is protein synthesis, a universal function where RNA molecules direct the assembly of proteins on ribosomes. This process uses transfer RNA (tRNA) molecules to deliver amino acids to the ribosome, where ribosomal RNA (rRNA) then links amino acids together to form proteins

Structure

Each nucleotide in RNA contains a ribose sugar, with carbons numbered 1' through 5'. A base is attached to the 1' position, in general, adenine(A), cytosine (C), guanine (G), or uracil (U). Adenine and guanine are purines, cytosine and uracil are pyrimidines.