Overview of Protein Synthesis: Videos & Practice Problems

The central dogma of molecular biology describes the flow of genetic information within a biological system. It states that genetic information flows from DNA to RNA to protein. This process involves two main stages: transcription and translation. During transcription, a segment of DNA is used as a template to synthesize messenger RNA (mRNA). In translation, the mRNA sequence is used to build a protein by assembling amino acids in the correct order. This concept is fundamental to understanding how genes are expressed and how genetic information is utilized to produce functional proteins necessary for cellular activities.

Messenger RNA (mRNA) plays a crucial role in protein synthesis by serving as the intermediary between DNA and proteins. During transcription, mRNA is synthesized from a DNA template, capturing the genetic code in a complementary RNA sequence. This mRNA then travels from the nucleus to the cytoplasm, where it serves as a template for translation. During translation, ribosomes read the mRNA sequence and use it to assemble amino acids into a polypeptide chain, ultimately forming a protein. Thus, mRNA is essential for conveying genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm, where proteins are synthesized.

Protein synthesis consists of two main stages: transcription and translation. In transcription, a segment of DNA is used as a template to synthesize messenger RNA (mRNA). This process occurs in the nucleus and involves the enzyme RNA polymerase, which assembles the mRNA strand based on the DNA sequence. Once transcription is complete, the mRNA molecule exits the nucleus and enters the cytoplasm. The second stage, translation, occurs in the cytoplasm at the ribosomes. During translation, the ribosome reads the mRNA sequence and assembles amino acids into a polypeptide chain according to the genetic code. This polypeptide chain then folds into a functional protein.

Transcription and translation are two distinct stages of protein synthesis. Transcription is the process of synthesizing messenger RNA (mRNA) from a DNA template. It occurs in the nucleus and involves the enzyme RNA polymerase, which reads the DNA sequence and assembles a complementary mRNA strand. Translation, on the other hand, is the process of synthesizing proteins based on the mRNA sequence. It occurs in the cytoplasm at the ribosomes. During translation, the ribosome reads the mRNA sequence and uses it to assemble amino acids into a polypeptide chain, which then folds into a functional protein. Thus, transcription converts DNA to mRNA, while translation converts mRNA to protein.

Gene expression is the process by which the information encoded in a gene is used to produce a functional product, typically a protein. It involves two main stages: transcription and translation. During transcription, a segment of DNA is transcribed into messenger RNA (mRNA). This mRNA then exits the nucleus and enters the cytoplasm, where it undergoes translation. During translation, the mRNA sequence is read by ribosomes, which assemble amino acids into a polypeptide chain based on the genetic code. This polypeptide chain then folds into a functional protein. Gene expression is essential for producing the proteins necessary for various cellular functions and activities.