DNA vs RNA: Structure and Function

• DNA and RNA are nucleic acids essential for protein synthesis.
• RNA is a single-stranded nucleotide sequence complementary to DNA and plays a significant role in gene expression.

Central Dogma of Molecular Biology

• Genes are expressed as proteins through a process summarized as:
  • DNA contains all genes for protein structure.
  • RNA is the messenger transcript copied from DNA.
  • The RNA transcript is translated to create a protein.

DNA vs. RNA: Key Differences

• DNA contains deoxyribose sugar, while RNA contains ribose sugar.
• DNA uses thymine, which pairs with adenine, while RNA uses uracil, which pairs with adenine.
• DNA is double-stranded, while RNA is single-stranded.
• DNA is stored and processed in the nucleus, while RNA is created in the nucleus and processed in the cytoplasm.

Molecular Stability

• DNA's double-stranded helix provides more structural stability than single-stranded RNA.
• RNA can easily fold onto itself, which affects its stability and lifespan.
• Ribonucleases break down RNA molecules.
• The deoxyribose sugar in DNA makes it more stable and prevents spontaneous hydrolysis.
• RNA's ribose sugar with an extra oxygen makes it more prone to hydrolysis.

DNA Structure and Function

• DNA is a double-stranded helix with a sugar-phosphate backbone and vertically stacked nucleic acids.
• DNA holds all genetic information and codes for all proteins within a cell.
• DNA is a unique identifier for each individual.
• DNA is kept solely in the nucleus of eukaryotic cells.
• Complementary nucleotides (adenine, cytosine, thymine, and guanine) held together by hydrogen-bonding maintain the DNA's double-helical structure.
• Adenine pairs with thymine, and cytosine pairs with guanine (A-T, C-G).
• DNA replicates within the nucleus.

RNA Structure and Function

• The three main types of RNA are tRNA, mRNA, and rRNA.
• Each RNA type has a different structure and purpose in protein synthesis.

Types of RNA

mRNA (messenger RNA)

• Carries the gene's message to be encoded into protein.
• Created in the nucleus and sent to the cytoplasm.
• It possesses a single-stranded linear structure.
• Functions as a messenger of genetic information from DNA to ribosomes

rRNA (ribosomal RNA)

• Forms ribosomal subunits for mRNA translation.
• Created in the nucleus and sent to the cytoplasm.
• It possesses a single-stranded and folded structure.
• Functions to form the ribosomal subunits necessary for translation of mRNA

tRNA (transfer RNA)

• Carries amino acids to build proteins.
• Created in the nucleus and sent to the cytoplasm.
• IT possesses a clover-shaped single-stranded structure.
• Functions as a carrier molecule delivering single amino acids to build protein

Other Types of RNA

• cRNA (coding RNA)
• ncRNA (noncoding RNA)
• snRNA (small nuclear RNA)
• miRNA (micro RNA) (can be coding or noncoding)

mRNA in Detail

• mRNA carries coding information outside the nucleus.
• mRNA can be considered a photocopy of DNA, protecting the original DNA.

rRNA in Detail

• rRNA functions to gather and organize amino acids to build proteins.
• rRNA molecules originate from the nucleolus and are released into the cytoplasm.
• rRNA forms the small subunits of a ribosome.

tRNA in Detail

• Shaped like single-stranded clover.
• Each tRNA carries a single amino acid associated with a nucleotide coding sequence.
• Each tRNA is roughly under 100 nucleotides.
• Each amino acid tRNA sequence contains 3 nucleotide bases known as anticodons.
• Anticodons pair with a complementary 3-base codon sequence on the mRNA.
• tRNA molecules join rRNA subunits to deliver the appropriate amino acid coded by the mRNA sequence.

Explore the structural and functional differences between DNA and RNA. Learn about the importance of DNA's stability, RNA's role in protein synthesis, and the significance of nucleotide differences.