Medical research

Solving the CNL6 mystery in Batten disease

Batten disease is a family of 13 rare, genetically distinct conditions. Collectively, they are the most prevalent cause of neurodegenerative disease in children, affecting 1 in 12,500 live births in the U.S. One of the Batten ...

Diseases, Conditions, Syndromes

A versatile antiviral emerges to fight COVID-19

Scientists everywhere are working overtime to develop treatments for COVID-19, the disease caused by the novel coronavirus SARS-CoV-2. Many existing drugs and new candidates are being tested, with the hope of easing the global ...

Medical research

Good news for menopausal women taking hops supplements

Hop-based dietary supplements that many women use to ease the night sweats and hot flashes commonly reported during menopause aren't likely to cause drug interactions, new research from Oregon State University's Linus Pauling ...

Genetics

A disease trigger for pancreatitis has been identified

Patients suffering from chronic pancreatitis experience an either recurring or permanent inflammation of their pancreas. "In many cases, people develop this disease because they are drinking too much alcohol or they are smoking ...

Medications

ACE inhibitor/ARB use not tied to COVID-19 test positivity

(HealthDay)—Angiotensin-converting enzyme inhibitor (ACEI) and/or angiotensin receptor blocker (ARB) use is not associated with COVID-19 test positivity, according to a study published online May 5 in JAMA Cardiology.

Diseases, Conditions, Syndromes

ACEIs/ARBs not linked to severity or mortality of COVID-19

(HealthDay)—For patients with hypertension hospitalized with COVID-19 infections, angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) are not associated with the severity or mortality of ...

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Enzyme

Enzymes are biomolecules that catalyze (i.e., increase the rates of) chemical reactions. Nearly all known enzymes are proteins. However, certain RNA molecules can be effective biocatalysts too. These RNA molecules have come to be known as ribozymes. In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, called the products. Almost all processes in a biological cell need enzymes to occur at significant rates. Since enzymes are selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell.

Like all catalysts, enzymes work by lowering the activation energy (Ea or ΔG‡) for a reaction, thus dramatically increasing the rate of the reaction. Most enzyme reaction rates are millions of times faster than those of comparable un-catalyzed reactions. As with all catalysts, enzymes are not consumed by the reactions they catalyze, nor do they alter the equilibrium of these reactions. However, enzymes do differ from most other catalysts by being much more specific. Enzymes are known to catalyze about 4,000 biochemical reactions. A few RNA molecules called ribozymes catalyze reactions, with an important example being some parts of the ribosome. Synthetic molecules called artificial enzymes also display enzyme-like catalysis.

Enzyme activity can be affected by other molecules. Inhibitors are molecules that decrease enzyme activity; activators are molecules that increase activity. Many drugs and poisons are enzyme inhibitors. Activity is also affected by temperature, chemical environment (e.g., pH), and the concentration of substrate. Some enzymes are used commercially, for example, in the synthesis of antibiotics. In addition, some household products use enzymes to speed up biochemical reactions (e.g., enzymes in biological washing powders break down protein or fat stains on clothes; enzymes in meat tenderizers break down proteins, making the meat easier to chew).

This text uses material from Wikipedia, licensed under CC BY-SA