A new way to control microbial metabolism

Microbes can be engineered to produce a variety of useful compounds, including plastics, biofuels, and pharmaceuticals. However, in many cases, these products compete with the metabolic pathways that the cells need to fuel ...

Biologists examine sperm quality on the basis of their metabolism

Every tenth couple worldwide is affected by infertility. The reasons for this are manifold, but mostly well researched. Nevertheless, about fifteen percent of cases remain unexplained. A team of biologists at TU Dresden has ...

The cause of chewy chicken meat

University of Delaware researchers have discovered that lipoprotein lipase, an enzyme crucial for fat metabolism, may be contributing to wooden breast syndrome in broiler chickens.

Study tracks evolutionary history of metabolic networks

By analyzing how metabolic enzymes are built and organized, researchers have reconstructed the evolutionary history of metabolism. Their study shows how metabolic networks—which drive every cellular process from protein ...

Shipment tracking for 'fat parcels' in the body

Without fat, nothing works in the body: Fats serve as energy suppliers and important building blocks, including for the envelopes of living cells. Numerous diseases are related to disorders in fat metabolism such as obesity ...

Cell biology: Compartments and complexity

Ludwig-Maximilians-Universitaet (LMU) biologists have taken a closer look at the subcellular distribution of proteins and metabolic intermediates in a model plant. The results of the study provide new insights into the dynamics ...

Preparing protocols for making deuterated biomolecules

Neutron techniques are good for studying light atoms like hydrogen—great for biological molecules that contain large numbers of them. Neutrons are particularly sensitive to isotopic substitution of hydrogen (1H) with deuterium ...

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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.

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