DNA Structure and Function

DNA Structure

• DNA has a double-helix structure, resembling a twisted ladder
• The "rungs" of the ladder are made up of nucleotide pairs
• Each nucleotide consists of three parts: sugar molecule (deoxyribose), phosphate group, and nitrogenous base
• There are four types of nitrogenous bases in DNA: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G)
• Base pairing follows a specific rule: Adenine always pairs with Thymine (A-T) and Cytosine always pairs with Guanine (C-G)

Function of DNA

• The sequence of bases along a DNA strand forms a genetic code
• The code is read in groups of three bases, called codons
• Each codon specifies a particular amino acid, which are the building blocks of proteins
• DNA provides instructions for making proteins through protein synthesis, involving transcription and translation
• Transcription: DNA is transcribed into messenger RNA (mRNA) in the cell nucleus
• Translation: mRNA travels to the ribosome in the cytoplasm, where it is translated into a specific protein

Replication and Importance of DNA

• DNA can replicate itself, ensuring each new cell has an identical copy of the DNA
• This is crucial for growth, repair, and reproduction
• DNA variations (mutations) are the source of genetic diversity in populations, driving evolution and adaptation
• DNA is passed from parents to offspring, carrying traits from one generation to the next
• Understanding DNA helps comprehend how organisms are built and function at a molecular level
• It also opens the door to biotechnological advances, such as genetic engineering and medical research