What Are 5 Steps of Protein Synthesis Quizlet?

1. Transcription
   • The first stage of protein synthesis. A segment of the DNA is copied into a molecule of RNA. During transcription, a specific enzyme called RNA polymerase reads the DNA code and creates a complementary RNA molecule.
   • The RNA polymerase binds to a specific region of the DNA called the promoter. (The promoter is a specific sequence of nucleotides.) The promoter signals the location of a gene that needs to be transcribed. Once RNA polymerase binds to the promoter, it unwinds the double helix by breaking the hydrogen bonds between the base pairs. This allows the two strands of the DNA to separate, exposing the genetic code so that it can be read by the RNA polymerase.
   • RNA polymerase adds nucleotides to the DNA and converts it into RNA, which is later modified into tRNA, mRNA, rRNA, and other RNAs. The mRNA moves to the ribosomes in the cytoplasm for the synthesis of proteins.
2. Translation
   • The second stage of protein synthesis. It uses the genetic information in RNA to build a sequence of amino acids, ultimately forming a protein. Translation occurs on ribosomes, which are structures in the cell that are responsible for protein synthesis.
3. Initiation
   • The translation process begins with the initiation phase, where a small subunit of the ribosome binds to the mRNA and a special initiator tRNA brings in the first amino acid at the AUG start codon. The ribosome scans the mRNA until it finds the start codon, AUG, and the small ribosomal subunit binds to the mRNA, followed by the larger subunit.
4. Elongation
   • The ribosome reads the sequence of codons on the mRNA. It matches them to the corresponding tRNAs, bringing in the correct amino acids to add to the growing polypeptide chain. The ribosome moves along the mRNA, reading the codons and adding the matching amino acids to the growing protein chain.
5. Termination
   • Finally, the ribosome reaches a stop codon, which signals the end of translation. The completed protein is then released into the cytoplasm. The ribosome reaches one of the three stop codons (UAA, UAG, or UGA). These release factors bind to these codons, releasing the newly synthesized protein into the cytoplasm.

The steps of protein synthesis occur in different parts of the cell, specifically the following:

• Transcription occurs in the cell's nucleus. RNA polymerase reads the DNA code and creates a complementary RNA molecule.
• Translation occurs in the cytoplasm. The RNA molecule created in the transcription process is read and translated into a sequence of amino acids, which will form a protein. Translation occurs on ribosomes, which are found in the cytoplasm.
• Post-transcriptional modification occurs in the nucleus and cytoplasm. After transcription, the primary transcript undergoes processing, such as capping, splicing, and tailing, to form different types of functional RNAs.

In prokaryotic cells, transcription and translation can occur simultaneously in the cytoplasm because the cell does not have a defined nucleus. In eukaryotic cells, the steps occur in different organelles. The transcription occurs in the nucleus, and then the mRNA is transported to the cytoplasm for translation.

If the body is unable to synthesize proteins, it can lead to several serious health problems.

• Growth and development: Stunted growth, delayed wound healing, and other developmental issues.
• Enzyme dysfunction: Various metabolic disorders.
• Hormone dysfunction: Several hormonal imbalances.
• Immune dysfunction: Increased susceptibility to diseases and infections.
• Muscles and movement: Muscle weakness and problems with movement.
• Anemia: A lack of hemoglobin can lead to anemia.
• Nutritional deficiencies: Malnutrition and various nutritional deficiencies.
• Genetic disorders: The replication and repair process of DNA is hampered, leading to genetic disorders.

A lack of protein synthesis can have wide-ranging and serious effects on the body and its functions. Maintaining a balanced diet that provides enough proteins to ensure the body's proper functioning is essential.

Proteins are essential for the proper functioning of cells, tissues, and organs. Several amino acids attached in long chains make proteins.

Some of the important functions of proteins

• Structural support: Collagen and elastin (proteins) provide structural support for cells, tissues, and organs. They make up the structure of the skin, hair, nails, and connective tissues, such as tendons and ligaments.
• Enzyme function: Enzymes are proteins that act as catalysts for chemical reactions in the body. These reactions include digestion, metabolism, and the synthesis of new molecules.
• Hormone function: Hormones are proteins that act as chemical messengers in the body, transmitting signals between cells and tissues. Hormones control many of the body's functions, including growth and development, metabolism, and reproductive processes.
• Oxygen transport: Proteins, such as hemoglobin in red blood cells and myoglobin in muscles, act as carriers for oxygen and other molecules throughout the body.
• Immune function: Proteins, such as antibodies and complement proteins, play a crucial role in the immune system, protecting the body from diseases and infections.
• Muscles and movement: Actin and myosin (proteins) are the main components of muscle fibers and are responsible for muscle contraction and movement.
• Storage: Ferritin and lactoglobulin (proteins) store iron and other essential nutrients.
• DNA replication and repair: Proteins play a role in the replication and repair of DNA, maintaining the integrity of the genetic code.

Proteins are essential for many of the body's functions, and their absence or malfunction can lead to serious health problems.