News tagged with cell metabolism

Related topics: insulin resistance · type 2 diabetes · fat cells · obesity · diabetes

On-and-off fasting helps fight obesity

Up to sixteen weeks of intermittent fasting without otherwise having to count calories helps fight obesity and other metabolic disorders. Such fasting already shows benefits after only six weeks. This is according to a study ...

Oct 17, 2017
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Menopause and estrogen affect muscle function

According to a study conducted at the University of Jyväskylä, estrogen acts as a regulator of muscle energy metabolism and muscle cell viability. Menopause leads to the cessation of ovarian estrogen production concurrent ...

Oct 03, 2017
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Our muscles measure the time of day

Biological clocks throughout the body trigger the release of the hormone melatonin during sleep, induce the secretion of digestive enzymes at lunchtime or keep us awake at the busiest moments of the day. A "master clock" ...

Oct 02, 2017
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New regulator of liver metabolism discovered

Researchers from Charité - Universitätsmedizin Berlin have identified an enzyme that has a major effect on glucose utilization in liver cells. The enzyme, retinol saturase, helps these cells adapt to variations in glucose ...

Sep 29, 2017
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Finding a natural defense against clogged arteries

In type 2 diabetes, chronic inflammation drives cardiovascular disease, the leading cause of death among people with the condition. Researchers at Joslin Diabetes Center now have identified an unexpected natural protective ...

Sep 20, 2017
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Metabolism

Metabolism is the set of chemical reactions that occur in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter, for example to harvest energy in cellular respiration. Anabolism, on the other hand, uses energy to construct components of cells such as proteins and nucleic acids.

The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed into another by a sequence of enzymes. Enzymes are crucial to metabolism because they allow organisms to drive desirable but thermodynamically unfavorable reactions by coupling them to favorable ones, and because they act as catalysts to allow these reactions to proceed quickly and efficiently. Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.

The metabolism of an organism determines which substances it will find nutritious and which it will find poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The speed of metabolism, the metabolic rate, also influences how much food an organism will require.

A striking feature of metabolism is the similarity of the basic metabolic pathways between even vastly different species. For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all organisms, being found in species as diverse as the unicellular bacteria Escherichia coli and huge multicellular organisms like elephants. These striking similarities in metabolism are most likely the result of the high efficiency of these pathways, and of their early appearance in evolutionary history.

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

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