Describe the process by which the information in a eukaryotic gene is transcribed and translated into a protein. Correctly use these words in your description: tRNA, amino acid, start codon, transcription, RNA splicing, exons, introns, mRNA, gene, codon, RNA polymerase, ribosome, translation, anticodon, peptide bond, stop codon.

Verified step by step guidance

1. Step 1: Transcription begins when RNA polymerase binds to a promoter region near the gene on the DNA. The DNA strands unwind, and the RNA polymerase uses one strand of DNA as a template to synthesize a pre-messenger RNA (pre-mRNA) transcript, incorporating RNA nucleotides that are complementary to the DNA template.
2. Step 2: RNA splicing occurs where the non-coding regions called introns are removed from the pre-mRNA. The remaining coding regions, called exons, are spliced together to form the mature mRNA. This mRNA sequence now contains only the information necessary to produce a protein.
3. Step 3: The mRNA is transported out of the nucleus and into the cytoplasm where translation occurs. At the ribosome, the process of translation begins with the mRNA binding to the ribosome. The ribosome reads the mRNA sequence starting at the start codon (AUG), which codes for the amino acid methionine.
4. Step 4: Transfer RNA (tRNA) molecules, each with an anticodon specific to its amino acid, match with the corresponding codon on the mRNA strand. Each tRNA carries a specific amino acid to the ribosome. The tRNA anticodon pairs with the mRNA codon, ensuring that the correct amino acid is added to the growing polypeptide chain.
5. Step 5: The ribosome moves along the mRNA, catalyzing the formation of peptide bonds between the amino acids as they are brought in by tRNAs. This process continues until a stop codon is reached on the mRNA, signaling the end of translation. The completed polypeptide chain is then released, and it folds into its functional three-dimensional protein structure.

Key Concepts

Transcription

Transcription is the process by which the genetic information in a eukaryotic gene is copied into messenger RNA (mRNA). This occurs in the nucleus, where RNA polymerase binds to the DNA at the promoter region, unwinding the DNA strands and synthesizing a complementary RNA strand. During transcription, introns (non-coding regions) are removed, and exons (coding regions) are spliced together to form mature mRNA, which then exits the nucleus.

Translation

Translation is the process by which the mRNA sequence is decoded to synthesize a protein. This occurs in the ribosome, where the mRNA is read in sets of three nucleotides called codons. Each codon corresponds to a specific amino acid, which is brought to the ribosome by transfer RNA (tRNA) molecules that have complementary anticodons. The ribosome facilitates the formation of peptide bonds between amino acids, creating a polypeptide chain until a stop codon is reached, signaling the end of protein synthesis.

Genetic Code

The genetic code is the set of rules that defines how the sequence of nucleotides in mRNA is translated into the sequence of amino acids in a protein. Each codon, a sequence of three nucleotides, specifies a particular amino acid or a stop signal. The start codon (AUG) initiates translation, while stop codons (UAA, UAG, UGA) terminate it. This code is universal across nearly all organisms, highlighting the commonality of life at the molecular level.