Our Connection to Life Science
Traditional Life Science is the study of biomedical topics such as evolution, as well as genetics, anatomy and physiology or topics that have to do with human society and functioning, such as psychology or anthropology.
Life sciences are all scientific fields that deal with the study of life. Biology is the main scientific field covered by the term, “life science,” but social sciences are also sometimes included, as they study the behavior of living beings. Many life sciences are interdisciplinary in nature, either between themselves or combining with other fields outside of the life sciences. For example, neurology often crosses over with psychology as well as with the non-life-science, chemistry.
More in-line with Energicx’s research is the study of the human body; anatomy, which is the study of the body’s internal and external structures while physiology studies the function of those structures, both singularly and in conjunction with one another.
Anatomy, which is sometimes called morphology, provides a map of how a body is put together, human or otherwise. The study of human anatomy is very important to the branches of medicine. This branch of biology includes dissections of different species to learn more about them, the study of how environmental and biological factors affect different species and the study of different biological systems.
Everything that is alive–from tiny cells to Stallions–relies on homeostasis, (balance), which is the way the physiological systems work together in living organisms to maintain a stable internal environment, despite changing external or environmental conditions. In humans, that means regulating things like energy, temperature, pH, hydration and blood oxygen levels.
All living things also require some sort of metabolism, which is commonly understood to mean breaking food down and turning it into energy. But in physiological terms, it refers to the entire range of an organism’s biochemical processes. These metabolic pathways involve enzymes that transform one substance into another substance, by either breaking one down (catabolism) or creating a new one (anabolism).
To accurately reference the structures they study, anatomists use positional and directional terms. In order to have a common standard for describing those positions of body parts, it is assumed the person is in what is called anatomical position: the body standing upright, feet together, palms facing forward. From this starting point, all the directional terms are relative to the anatomical position.
There are three main body planes: the sagittal, which divides the body into left and right halves; the frontal which divides the body into front and back halves (ventral and dorsal, or anterior and posterior); and the transverse which divides the body into upper (toward the head) and lower (toward the feet) halves (superior and inferior). Additionally, the outer body is divided into two regions: the axial, which includes the head, neck and trunk, and the appendicular which consists of the limbs.
The same terms are used when describing the skeleton. The skull, ribs, and spinal vertebrae belong to the axial skeleton. These bones protect the major organs such as the brain, heart, and lungs. Also included in the axial skeleton are the three inner ear bones–malleus, incus, and stapes–known collectively as the ossicles, and the hyoid in the throat. There are 80 bones in the axial skeleton. The appendicular skeleton consists of the 126 bones of our extremities–legs, arms, hands, and feet–which facilitate movement.
The body is a complex organism of cells, tissues, organs, and organ systems. While anatomy describes the structure of how it is physically put together, physiology explains how all the components of the human organism work, individually and together, to maintain life.
Life’s Energy
Energy is the currency of biology. By harvesting electrons from a stunning range of starting materials, Earth’s organisms produce adenosine triphosphate (ATP), which powers biological reactions. In the case of mammals and most microbial organisms, (eukaryotes), sugars and other organic molecules are common electron sources, the oxidation of which drives ATP production. Bacteria and archaea can use a range of other chemicals, from sulfide to iron to ammonium.
Our cells take up these electron-rich molecules and capture their electrons, which jump down an electron transport chain in the mitochondrial or cell membrane. As electrons move along the membrane toward a final electron acceptor, protons are pumped from the cell’s interior to the exterior, setting up a chemical gradient.
Finally, protons stream back into the cell, releasing the chemical pressure and generating ATP. With each energy-requiring reaction, from flagella construction to cell division and growth, cells draw upon their ATP bank.
This elegant, multistep process is a universal feature of life as we know it, but energetic challenges are ever-present. If the electrical potentials of electron donor and acceptor are too closely aligned, for example, it won’t be possible to squeeze much energy from their coupling. The concentrations of the reactants and the speed at which enzymes can mobilize them are also key factors. These two components—the magnitude of energy available from a pairing and the rate of such reactions—determine how much energy a cell can produce.
Cataloging the biochemical parts list of a cell is one challenge. Individual biosynthetic pathways—the production of lipids from glycerol derivatives, for example—are relatively well characterized under “standard” conditions, but a cell’s ever-changing chemical environment can render baseline calculations inaccurate.
Scaled over millions of such reactions, the margin of error may be a substantial proportion of the available energy. And this is just considering the biosynthesis of new cellular material. In most environments, microbes must always be vigilant against biochemical breakdown resulting from environmental stresses, calling on energy reserves to restore old enzymes or patch holes in cell walls. Competition among residents may also demand additional energy expenditure, such as powering flagella to swim around in search of food or producing antibiotic molecules to keep predatory neighbors at bay.
If, we are able to estimate how much energy is required for survival, and compare that to how much energy is available to be extracted from the environment, we can begin to consider “extreme” organisms in a more objective fashion. Some of the most “exotic” environments offer luxurious energetic balances; it’s the microbes with low net energy availability that are the real extremophiles, whether they live an expensive existence in a high-energy environment, or an ascetic life in an energetic desert.
References
- Vieille, G.J. Zeikus, “Hyperthermophilic enzymes: Sources, uses, and molecular mechanisms for thermostability,” Microbiol Mol Biol R, 65:1-43, 2001.
- M. McCollom, J.P. Amend, “A thermodynamic assessment of energy requirements for biomass synthesis by chemolithoautotrophic micro-organisms in oxic and anoxic environments,” Geobiology, 3:135-44, 2005.
- S. Rokem et al., “Systems biology of antibiotic production by microorganisms,” Nat Prod Rep, 24:1262-87, 2007.
- Boetius et al., “A marine microbial consortium apparently mediating anaerobic oxidation of methane,” Nature, 407:623-26, 2000.
- J. Marlow et al., “Microbial abundance and diversity patterns associated with sediments and carbonates from the methane seep environments of Hydrate Ridge, OR,” Front Mar Sci, doi:10.3389/fmars.2014.00044, 2014.
- J. Marlow et al., “Carbonate-hosted methanotroph represents an unrecognized methane sink in the deep sea,” Nat Comm, 5:5094, 2014.