Nucleic Acids: Structure and Composition

Structure and Composition

• Nucleic acids are long-chain biomolecules composed of nucleotides
• Each nucleotide consists of:
  • A five-carbon sugar (deoxyribose in DNA, ribose in RNA)
  • A phosphate group
  • A nitrogenous base (adenine, guanine, cytosine, thymine, or uracil)

Types of Nucleic Acids

• DNA (Deoxyribonucleic acid):
  • Double-stranded, helical structure
  • Contains the genetic instructions for an organism
  • Thymine (T) is one of the nitrogenous bases
• RNA (Ribonucleic acid):
  • Typically single-stranded, but can form complex secondary structures
  • Involved in protein synthesis, gene regulation, and other cellular processes
  • Uracil (U) replaces thymine (T) as one of the nitrogenous bases

Functions

• Storage and transmission of genetic information:
  • DNA contains the genetic code for an organism
  • RNA plays a crucial role in transmitting genetic information from DNA to the ribosome
• Protein synthesis:
  • RNA molecules (mRNA, tRNA, rRNA) are involved in protein synthesis
  • mRNA carries genetic information from DNA to the ribosome
  • tRNA brings amino acids to the ribosome
  • rRNA forms part of the ribosome itself
• Regulation of gene expression:
  • RNA molecules (miRNA, siRNA) can regulate gene expression by binding to specific mRNA molecules

Importance

• Nucleic acids are essential for life, as they contain the genetic instructions for an organism
• Understanding nucleic acids has led to significant advances in fields such as genetics, genomics, and biotechnology

Structure and Composition of Nucleic Acids

• Nucleic acids are long-chain biomolecules composed of nucleotides
• Each nucleotide consists of a five-carbon sugar, a phosphate group, and a nitrogenous base

Types of Nucleic Acids

• DNA (Deoxyribonucleic acid)
  • Double-stranded, helical structure
  • Contains the genetic instructions for an organism
  • Thymine (T) is one of the nitrogenous bases
• RNA (Ribonucleic acid)
  • Typically single-stranded, but can form complex secondary structures
  • Involved in protein synthesis, gene regulation, and other cellular processes
  • Uracil (U) replaces thymine (T) as one of the nitrogenous bases

Functions of Nucleic Acids

Storage and Transmission of Genetic Information

• DNA contains the genetic code for an organism
• RNA plays a crucial role in transmitting genetic information from DNA to the ribosome

Protein Synthesis

• RNA molecules (mRNA, tRNA, rRNA) are involved in protein synthesis
• mRNA carries genetic information from DNA to the ribosome
• tRNA brings amino acids to the ribosome
• rRNA forms part of the ribosome itself

Regulation of Gene Expression

• RNA molecules (miRNA, siRNA) can regulate gene expression by binding to specific mRNA molecules

Importance of Nucleic Acids

• Nucleic acids are essential for life, as they contain the genetic instructions for an organism
• Understanding nucleic acids has led to significant advances in fields such as genetics, genomics, and biotechnology