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Protein Synthesis Overview: Involves the processes of transcription and translation. Genes in DNA direct the synthesis of proteins, which control chemical reactions and provide structural components such as muscle filaments.

Nucleic Acids: Two essential nucleic acids involved: DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid).

• DNA:

  • Sugar: Deoxyribose

  • Structure: Double-stranded helix

  • Bases: Adenine (A), Guanine (G), Cytosine (C), Thymine (T)

  • Remains in the nucleus and does not leave.

• RNA:

  • Sugar: Ribose

  • Structure: Single-stranded

  • Bases: Adenine (A), Guanine (G), Cytosine (C), Uracil (U) (uracil replaces thymine)

  • Can leave the nucleus to function in the cytoplasm.

Types of RNA:

• mRNA (Messenger RNA):

  • Carries genetic information from DNA to the ribosomes for protein synthesis.

• tRNA (Transfer RNA):

  • Delivers specific amino acids to the ribosome during protein synthesis based on mRNA codons.

• rRNA (Ribosomal RNA):

  • Structural component of ribosomes, facilitates the synthesis of proteins.

Enzymes Involved in Protein Synthesis:

• Helicase:

  • Function: Unwinds and separates the double-stranded DNA during replication and transcription.

• DNA Polymerase:

  • Function: Synthesizes new DNA strands by adding nucleotides to a growing chain during DNA replication.

• RNA Polymerase:

  • Function: Synthesizes mRNA from the DNA template during transcription, pairing RNA nucleotides with complementary DNA bases.

Processes of Protein Synthesis:

• Transcription

  • Purpose: Convert DNA information into mRNA.

  • Steps:

    • DNA unwinds (unzips) to expose bases.

    • RNA polymerase pairs free RNA nucleotides with the exposed DNA bases in a complementary manner.

    • mRNA is synthesized from the DNA template, forming codons (three-letter groups).

    • mRNA exits the nucleus and enters the cytoplasm.

• Translation

  • Purpose: Convert mRNA sequence into a polypeptide chain (protein).

  • Steps:

    • mRNA binds to the ribosome in the cytoplasm.

    • tRNA carrying amino acids recognizes and pairs with the complementary mRNA codons through anticodons.

    • Amino acids linked together to form peptide bonds, creating a growing polypeptide chain until a stop codon is reached (UAA, UAG, UGA).

    • The protein synthesis process continues until the entire mRNA strand is translated, resulting in a functional protein.

Codon to Amino Acid Mapping:

Summary: DNA holds the instructions for creating proteins, with various types of RNA playing crucial roles in the process of transcription (making mRNA from DNA) and translation (building proteins from mRNA). The sequence of nucleotides (codons) is critical as it determines which amino acids are added to the growing polypeptide chain during protein synthesis, ultimately resulting in