Nucleic Acids Structure and Function

Structure and Function

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

Types of Nucleic Acids

• DNA (Deoxyribonucleic acid):
  • Double-stranded helix
  • Sugar molecule is deoxyribose
  • Found in the nucleus of eukaryotic cells and in prokaryotic cells
  • Contains the genetic instructions for an organism
• RNA (Ribonucleic acid):
  • Usually single-stranded
  • Sugar molecule is ribose
  • Found in the nucleus, cytoplasm, and ribosomes of cells
  • Involved in protein synthesis, catalysis, and gene regulation

Nucleotide Composition

• Base pairing:
  • Adenine (A) pairs with Thymine (T) in DNA
  • Adenine (A) pairs with Uracil (U) in RNA
  • Guanine (G) pairs with Cytosine (C) in both DNA and RNA
• Chargaff's rules:
  • The amount of adenine is equal to the amount of thymine (A=T)
  • The amount of guanine is equal to the amount of cytosine (G=C)

Functions of Nucleic Acids

• Genetic information storage: DNA contains the genetic instructions for an organism
• Protein synthesis: RNA molecules (mRNA, tRNA, rRNA) play a crucial role in the process of protein synthesis
• Gene regulation: RNA molecules (miRNA, siRNA) regulate gene expression by controlling mRNA translation
• Catalysis: Some RNA molecules (ribozymes) have enzymatic properties and can catalyze chemical reactions

Structure and Function

• Nucleic acids are comprised of nucleotides, which are made up of a five-carbon sugar, a phosphate group, and a nitrogenous base.
• The five-carbon sugar can be either ribose or deoxyribose, depending on the type of nucleic acid.
• There are five nitrogenous bases found in nucleic acids: adenine, guanine, cytosine, thymine, and uracil.

Types of Nucleic Acids

DNA (Deoxyribonucleic acid)

• Double-stranded helix structure
• Deoxyribose is the sugar molecule
• Found in the nucleus of eukaryotic cells and in prokaryotic cells
• Stores genetic instructions for an organism

RNA (Ribonucleic acid)

• Usually single-stranded
• Ribose is the sugar molecule
• Found in the nucleus, cytoplasm, and ribosomes of cells
• Involved in protein synthesis, catalysis, and gene regulation

Nucleotide Composition

Base Pairing

• Adenine (A) pairs with Thymine (T) in DNA
• Adenine (A) pairs with Uracil (U) in RNA
• Guanine (G) pairs with Cytosine (C) in both DNA and RNA

Chargaff's Rules

• The amount of adenine is equal to the amount of thymine (A=T)
• The amount of guanine is equal to the amount of cytosine (G=C)

Functions of Nucleic Acids

Genetic Information Storage

• DNA contains genetic instructions for an organism

Protein Synthesis

• RNA molecules (mRNA, tRNA, rRNA) play a crucial role in protein synthesis

Gene Regulation

• RNA molecules (miRNA, siRNA) regulate gene expression by controlling mRNA translation

Catalysis

• Some RNA molecules (ribozymes) have enzymatic properties and can catalyze chemical reactions

Learn about the composition and types of nucleic acids, including DNA and RNA. Understand the structure of nucleotides and their roles in genetic instructions.