Dna

                              

  DNA

Deoxyribonucleic acid, or DNA, is a biologicalmacromolecule that carries hereditary informationin  many organisms. DNA is necessary for the production of proteins, the regulation, metabolism, and reproduction of the cell. 

Large compressed DNA molecules with associated proteins, called chromatin, are mostly present inside the nucleus. Some cytoplasmic organelles like the mitochondria also contain DNA molecules.

` DNA is usually a double-stranded polymer of nucleotides, although single-stranded DNA is also known  Nucleotides in DNA are molecules made of deoxyribose sugar, a phosphate and a nitrogenous base. The nitrogenous bases in DNA are of four types – adenine, guanine, thymine and cytosine. The phosphate and the deoxyribose sugars form a backbone-like structure, with the nitrogenous bases extending out like rungs of a ladder. Each sugar molecule is linked through its third and fifth carbon atoms to one phosphate molecule each.

Functions of DNA

DNA was isolated and discovered chemically before its functions became clear.DNA and its related molecule, ribonucleic acid (RNA), were initially identified simply as acidic molecules that were present in the nucleus. 

When Mendel’s experiments on genetics were rediscovered, it became clear that heredity was probably transmitted through discrete particles, and that there was a biochemical basis for inheritance.

Biomolecules:

A series of experiments demonstrated that among the four types of macromolecules within the cell (carbohydrates, lipids, proteins and nucleic acids), the only chemicals that were consistently transmitted from one generation to the next were nucleic acids.  As it became clear that DNA was the material that was transferred from one generation to the next, its functions began to be investigated.Biomolecules are essential substances produced by cells and living organisms. They come in various sizes and structures, performing a wide array of functions. Let’s delve into the four major types of biomolecules:

Carbohydrates: These molecules, primarily composed of carbon, hydrogen, and oxygen atoms, serve as both energy sources and structural components. Carbohydrates include monosaccharides (single sugar units), disaccharides (two sugar units), oligosaccharides, and polysaccharides . They’re abundant and vital for life on Earth.

Lipids: Lipids play diverse roles in living organisms. They act as stored energy sources, form cell membranes, and serve as chemical messengers. Examples of lipids include fats, phospholipids, and steroids 1.

Nucleic Acids: These biomolecules store an organism’s genetic code. The two main types are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). DNA carries genetic information, while RNA plays a role in protein synthesis .

Proteins: Proteins are crucial for life. They serve as structural elements in cells, transporters for nutrients, enzymes that drive chemical reactions, antibodies, and hormones. The sequence of amino acids within proteins determines their structure and function 1.

Micromolecules

• Definition: Micromolecules are relatively small molecules with low molecular weight. They contain only a small number of atoms.

• Monomers: Micromolecules are often referred to as monomers. These monomers serve as the building blocks for larger molecules.

• Examples:

• Amino Acids: These micromolecules combine to form proteins.

• Monosaccharides (Simple Sugars): They are the basic units of carbohydrates.

• Nucleotides: These form the backbone of nucleic acids (DNA and RNA).

• Fatty Acids: Essential components of lipids.

• Glycerol: A key component in lipid structure.

• Minerals and Water: Inorganic micromolecules vital for various cellular processes.

• Role:

• Micromolecules participate in biochemical reactions, metabolic processes, and substrate supply.

• Formation of Macromolecules:

• Micromolecules join together through biochemical reactions to create macromolecules.

Micromolecules

• Definition:

• Macromolecules are large molecules with high molecular weight. They result from the combination of smaller micromolecules (monomers).

• Examples:

• Proteins: Composed of amino acid monomers.

• Carbohydrates: Formed by linking monosaccharides.

• Lipids: Assembled from glycerol and fatty acids.

• Nucleic Acids: DNA and RNA consist of nucleotide monomers.

• Function:

• Macromolecules play critical roles in cells, such as maintaining structure, acting as enzymes, and storing genetic information.

• Complexity:

• Unlike micromolecules, macromolecules are relatively large and complex.

• Cellular Composition:

• Cells contain various macromolecules that interact to sustain life.