Cell Organelles, their Functions, and Protein Synthesis

There are several organelles in human cells, each of which has a distinct purpose. The DNA or genetic material of the cell is located in the nucleus and is greatly involved in controlling protein synthesis. The cell membrane encloses the cell and regulates how substances enter and exit the cell. The mitochondria are in charge of cellular respiration, which is how the cell produces energy. Within the cell, the Golgi apparatus and endoplasmic reticulum collaborate to process and transport proteins and lipids (Marieb & Hoehn, 2019). The synthesis of proteins is carried out by ribosomes. Enzymes that digest wastes and foreign substances are found in the lysosomes. The gel-like material that fills the cell and houses all the organelles is called the cytoplasm. The cytoskeleton is a network of protein fibers that gives the cell structure and support. Cell division is done by the centrioles.

Cells make new proteins through a process called protein synthesis. It occurs in the ribosomes and involves the transcription of DNA to RNA and the translation of RNA to proteins. The first step in protein synthesis is transcription, which occurs in the nucleus. An enzyme known as RNA polymerase copies a specific piece of DNA into a molecule of messenger RNA (mRNA) during transcription (Silverthorn, 2019). Translation follows and takes place in the cytoplasm. After leaving the nucleus and moving into the cytoplasm, the mRNA molecule interacts with a ribosome. The ribosome reads the mRNA's base sequence and compares it to the matching amino acid sequence for the protein. Transfer RNA (tRNA) molecules are responsible for delivering these amino acids to the ribosome. The amino acids are joined by the ribosome to create a protein chain. This process continues until the ribosome encounters a stop codon on the mRNA, which indicates that protein synthesis has come to an end. The result is a functioning protein that the cell may use for a variety of purposes.

References

Marieb, E. N., & Hoehn, K. (2019). Human anatomy & physiology (Eleventh edition, Global edition.). Pearson.

Silverthorn, D. U. (2019). Human physiology : an integrated approach (Eighth, Global edition.). Pearson.