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About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life.
High solubility of oxygen and carbon dioxide at room temperature supporting the evolution of aerobic aquatic plant and animal life. A high heat capacity (leading to higher environmental temperature stability). Water is a room-temperature liquid leading to a large population of quantum transition states required to overcome reaction barriers.
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid. In human physiology and psychology , sound is the reception of such waves and their perception by the brain . [ 1 ]
Light micrograph of a moss's leaf cells at 400X magnification. The following outline is provided as an overview of and topical guide to cell biology: . Cell biology – A branch of biology that includes study of cells regarding their physiological properties, structure, and function; the organelles they contain; interactions with their environment; and their life cycle, division, and death.
This falls within the domain of physical acoustics. In fluids, sound propagates primarily as a pressure wave. In solids, mechanical waves can take many forms including longitudinal waves, transverse waves and surface waves. Acoustics looks first at the pressure levels and frequencies in the sound wave and how the wave interacts with the ...
Typical eukaryotic cell. Cellular respiration is the process by which biological fuels are broken down in the presence of a hydrogen acceptor, such as oxygen, to drive the production of adenosine triphosphate (ATP), which stores chemical energy in a biologically accessible form.
The vocal cords are composed of twin infoldings of 3 distinct tissues: an outer layer of flat cells that do not produce keratin (squamous epithelium). Below this is the superficial layer of the lamina propria , a gel-like layer, which allows the vocal fold to vibrate and produce sound.
Sound energy causes changes in the shape of these cells, which serves to amplify sound vibrations in a frequency specific manner. Lightly resting atop the longest cilia of the inner hair cells is the tectorial membrane , which moves back and forth with each cycle of sound, tilting the cilia, which is what elicits the hair cells' electrical ...