DNA Structure

You’ve probably heard the phrase “It’s in my DNA” a few times and wondered what it meant. Every living organism on our planet Earth contains DNA, which is a genetic material. These structures carry the genetic instructions, which are responsible for how an organism develops, grows, reproduces, and functions from generation to generation. So, let’s get into some of the material’s fundamentals and details.

DNA

Every living entity has DNA, which is a self-replicating genetic material. It serves as a repository for all genetic data. It contains instructions on how to grow, survive, develop, and reproduce for organisms. It’s a lengthy molecule with a genetic “coding” in it. This genetic code serves as a foundation for human growth. External factors such as lifestyle, nutrition, and the environment, however, can have an impact on human evolution.

Who was the first to discover DNA? DNA was discovered in 1869 by Swiss biologist Johannes Friedrich Miescher while examining white blood cells, contrary to popular perception that it was discovered in the 1950s by biologists James Watson and Francis Crick. He was conducting a series of studies in which he discovered the presence of DNA, its chemical components, and how they interacted.

Full form of DNA – DNA stands for Deoxyribonucleic acid. If we spell the word:

Deoxy means a missing oxygen atom 

Ribo stands for Ribose sugar

Nucleic is present in the nucleus of cells

Acid – phosphate ion which is negatively charged and acidic

Components of the DNA molecule – Nucleotides are the molecules that make up DNA. The carbon-sugar group, phosphate group, and nitrogen base are the three components of a DNA molecule. Adenine (A), Cytosine (C), Guanosine (G), and Thymine (T) are the four different nitrogen bases (T).

DNA Structure – Human DNA is made up of 3 billion base pairs and is unique. In humans, however, 99 percent of them are the same. The order in which these bases are coded dictates what information is required for the organism’s growth and development. A product known as RNA is generated during the transcription process (when DNA is copied) (Ribonucleic Acid). This RNA is in charge of converting genetic information from DNA to protein and then reading ribosomes.

DNA molecules are polymers made up of smaller molecules called monomers that are linked together to form larger molecules. Nucleotides, which are made up of monomers, are the smallest units of DNA. The nucleotide monomers create a DNA molecule when they come together.

A nitrogen base, sugar group, and phosphate group make up nucleotides. The backbone of this structure is sugar. Adenine (A), Thymine (T), Guanine (G), and Cytosine (C) are the four types of nitrogen bases (C). With each other, the nitrogen bases form a unit known as a “base pair,” with A pairing with T and C pairing with G. The base pairs are then joined to a sugar and nitrogen molecule to form a nucleotide. 

The distance between any two base pairs is 0.34 nm since each helix has a pitch of 3.4 nm. These nucleotides join together to produce two long strands that spiral in opposite directions to form a structure known as a double helix. The rungs of a double helix are composed of nitrogen base, and the phosphate and sugar groups are found on both sides.

DNA is usually found in the nucleus of a cell (where it is referred to as nuclear DNA), but a tiny quantity of it is also found in mitochondria and is referred to as mitochondrial DNA. Mitochondria are our bodies’ powerhouses, converting the food we eat into energy.

How does the DNA work?

DNA is the most vital component of any living organism. It provides crucial information about a trait that is passed down from generation to generation. DNA molecules are securely linked together in the nucleus of a cell to create chromosomes, which secure DNA and preserve it in one place. It stores the information needed to determine an individual’s genetic information in the form of genes.

The DNA replicates itself into RNA ( a single-stranded molecule). If DNA is the blueprint, it’s reasonable to believe that RNA is the translator of the blueprint’s instructions. The DNA unwinds into two single strands during the replication process.

Although RNA is identical to DNA, it has certain fundamental molecular distinctions that distinguish it from DNA. RNA serves as a messenger and transports crucial genetic information. Ribosomes transfer this information into proteins (the process of protein creation through RNA), which are then used to create living creatures.

DNA Functions- Genes are the carriers of this genetic information. Genes are tiny bits of DNA that contain about two million base pairs. On a single amino acid, a gene coding for a polypeptide molecule counts three nitrogenous bases.

To generate distinct proteins, polypeptide chains are further coiled into secondary, tertiary, and quaternary structures. Various proteins can be generated since different organisms possess numerous genes.

In most organisms, proteins are the most important structural and functional units. The most significant purpose of DNA, aside from preserving genetic information, is to transmit genetic information from generation to generation, which is coded in the way the nitrogen bases are ordered in nucleotides. The following are some of DNA’s other functions:

Cellular Metabolism- DNA regulates the metabolic activities of cells by utilising enzymes, hormones, and particular RNAs (ribonucleic acid responsible for gene regulation and expression).

Transcription- RNAs are produced from DNAs through transcription

DNA Replication- DNA replication is the process of passing genetic information from one cell to its daughter cells, and from one generation to the next. Through duplication, it creates carbon duplicates.

Development of Organisms- The development of organisms is governed by the internal genetic clock mechanism, which is controlled by DNA molecules.

DNA Fingerprinting- Each person’s DNA sequence is unique and cannot be matched with that of another person. This characteristic is useful in DNA fingerprinting, which is used to identify a person based on their DNA.

Mutations- The variations in DNA sequencing that occur. Errors in DNA replication result in mutations. However, errors can occur as a result of UV radiation exposure, deletion or insertion of DNA sequences, and other factors.

Gene Therapy- Gene Therapy is a process in which a person’s gene is altered in order to cure an illness. Gene therapy can act through a variety of mechanisms, including

• Using a healthy copy of a gene to replace a disease-causing gene.
• Inactivating a disease-causing gene that is malfunctioning.
• To treat disorders, a modified or new gene is introduced into the body.

Types of DNA– There are four major types of double-stranded DNA. The interaction of complementary base pairs connects them.

B-form DNA– This is the most common type of DNA, in which two strands of DNA are coiled around the same axis, each in a right-hand helix. The two strands are held together by H-bonding between the bases.

A-form DNA is similar to B-form DNA in that it is a right-handed double-helical structure with a thicker structure and a shorter space between base pairs. When DNA is dehydrated, it converts to the A form to protect it from harsh circumstances like desiccation. When protein binding removes the solvent from DNA, it can also form.

Z-form DNA– This is the third type of duplex DNA; however, it has a left-handed helical helix. In Z-form DNA, a zigzag structure is formed by alternating purines and pyrimidines. Because it is found at the start of a gene, it is thought to play a function in gene regulation and transcription.

Conclusion

The DNA’s Future is developing with researchers working hard to understand the complexity linked with DNA, therefore it has a bright future. We can expect a world with fewer and better-managed diseases, better treatment options, and a longer life span if the research continues.