6.4.1 Distinguish between ventilation, gas exchange and cell respiration. ventilation: the process of bringing fresh air into the alveoli and removing stale air. gas exchange: human must take in oxygen from their surrounding and release carbon dioxide, this process of swapping one gas with another is called gas exchange. cell respiration: the controlled release of energy in the form of ATP from organic compounds in cells. 6.4.2 Explain the need for a ventilation system. Diffusion of oxygen and carbon dioxide happens because there are concentration gradients of oxygen and carbon dioxide between the air and the blood.
polysaccharide polÂ·yÂ·sacÂ·chaÂ·ride (pÅl'Ä-sÄk'É-rÄ«d') or polÂ·yÂ·sacÂ·chaÂ·rid (-rÄ­d) or polÂ·yÂ·sacÂ·chaÂ·rose (-rÅs', -rÅz') n. Any of a class of carbohydrates, such as starch and cellulose, consisting of a number of monosaccharides joined by glycosidic bonds. Also called glycan.
Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages and on hydrolysis give the constituent monosaccharides or oligosaccharides. They range in structure from linear to highly branched.