Genes work by providing the instructions for building proteins, which carry out a vast array of functions within a cell and the body. This process involves two main steps: transcription and translation.
Transcription: From DNA to RNA
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The Role of DNA: Genes are made of DNA, which contains the genetic code. This code is like a blueprint containing all the information needed for an organism to develop, function, and reproduce.
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RNA's Function: Because DNA is safely tucked away inside the nucleus (in eukaryotic cells), it needs a messenger to carry its instructions to the ribosomes, where proteins are made. This messenger is RNA (ribonucleic acid), and the process of creating it from a DNA template is called transcription.
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The Transcription Process: An enzyme called RNA polymerase binds to a specific region of the DNA near a gene. It then unwinds the DNA and uses one strand as a template to create a complementary RNA molecule, specifically messenger RNA (mRNA). This mRNA molecule carries the genetic code out of the nucleus.
Translation: From RNA to Protein
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mRNA's Journey: The mRNA molecule travels from the nucleus to the ribosomes, which are located in the cytoplasm.
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The Role of Ribosomes: Ribosomes are protein-synthesizing machines. They read the mRNA sequence in three-nucleotide units called codons. Each codon specifies a particular amino acid.
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tRNA's Function: Transfer RNA (tRNA) molecules bring the appropriate amino acids to the ribosome, matching their anticodon sequence to the mRNA codon.
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Protein Synthesis: As the ribosome moves along the mRNA, tRNA molecules deliver amino acids, which are linked together by peptide bonds to form a growing polypeptide chain. This chain folds into a specific three-dimensional structure, resulting in a functional protein.
Summary
In essence, genes work through a two-step process: transcription, where DNA's instructions are copied into mRNA, and translation, where ribosomes use mRNA to assemble amino acids into proteins. These proteins then perform a wide variety of functions within the cell, ultimately determining an organism's traits. Some genes produce regulatory molecules that help the cell assemble proteins
