Category: Proteins

Proteins are essential for life and are essential for a wide range of cellular activities. Protein enzymes catalyze the vast majority of chemical reactions that occur in the cell. Proteins provide many of the structural elements of a cell, and they help to bind cells together into tissues. Proteins, in the form of antibodies, protect animals from disease, and many hormones are proteins. Proteins…

Proteins are not stored for later use in animals. When an animal consumes excess proteins, they are converted into fats (glucose or triglycerides) and used to supply energy or build energy reserves. If an animal is not consuming sufficient protein, the body begins to break down protein-rich tissues, such as muscles, leading to muscle wasting and eventually death if…

Protein synthesis occurs in the ribosomes of cells. In eukaryotic cells, ribosomes are found as free-floating particles within cells and are also embedded in the rough endoplasmic reticulum, a cell organelle.

A protein is a naturally occurring, extremely complex substance that consists of amino acid residues joined by peptide bonds. Proteins are present in all living organisms and include many essential biological compounds such as enzymes, hormones, and antibodies.

Proteins have several functions. Some of them are structural components (e.g. keratin in hair, actin, and myosin in muscle, etc.). Many proteins are enzymes. They catalyze various biochemical reactions and therefore are essential to metabolism. Other vital roles of proteins in biological systems are as follows: as transporters (e.g. hemoglobin), as antibodies, and as regulators of gene expression. Not all proteins are…

The lifespan of proteins varies depending on their kind. Some proteins are degraded after a few minutes of production; others remain for years. Misfolded proteins are degraded at once to prevent them from causing damage due to their instability and dysfunctional nature. The cell may degrade or recycle them through protein turnover. Proteins may be degraded…

Protein synthesis is the creation of proteins. In biological systems, it is carried out inside the cell. In prokaryotes, it occurs in the cytoplasm. In eukaryotes, it initially occurs in the nucleus to create a transcript (mRNA) of the coding region of the DNA. The transcript leaves the nucleus and reaches the ribosomes for translation into a protein molecule with a specific sequence…

Proteins are composed of polymers of amino acid residues. The amino acids are joined together by peptide bonds. Each protein is a linear polymer built from different amino acids. The type and the sequence of amino acids in a protein are specified by the DNA in the cell that produces them. The genetic code typically specifies 20 standard amino acids. However, some organisms, such as archaea, have…

The word protein is derived from the Greek proteios, meaning “of the first rank”. The term was coined in 1838 by the Swedish scientist Jöns Berzelius, to reflect the importance of this group of molecules. A stretch of DNA called a gene carries the information required to build a protein.