Bios 251

BIOS 251N Week 2 Short Answer

Functions of Water:

Water is the most abundant inorganic compound. Water has solvent properties, chemical properties, thermal properties, and lubrication properties. For its chemical properties, water is polar, meaning it has uneven valence electrons. Valence electrons determine the chemical makeup of an element. Water is made up of one oxygen and two hydrogen atoms. It contains a negative charge on the oxygen side, and a positive charge near the two hydrogen atoms. This allows for water to stick together, and thank goodness, because humans cannot survive long without it! Water has solvent properties, because it dissolves the solute. Hydrophilic refers to solutes that have polar covalent bonds. Hydrophilic translates to “water loving” and means a solute can dissolve in water. Sugar and salt are examples the book gives of hydrophilic substances. Water’s thermal properties mean it can deal with high amounts of heat. Water has a high heat capacity, which is why it is used in engines. Water also helps maintain homeostasis in the human body. As a lubricant, water is vital to our organs. Water helps the organs, joints, and bones slip and slide amongst one another. (pg. 40-41)

Digestion of Cellulose:

Cellulose is a polysaccharide formed from plant glucose. It cannot be digested by humans because we do not have the enzymes necessary to break it down. A polysaccharide is a group of carbohydrates that are water insoluble.

(pg. 46-47)

Functions of Proteins:

The functions of proteins are structural, regulatory, contractile, immunological, transport, and catalytic. For structural functions, proteins provide framework for body parts. For regulatory functions, they function as hormones. For instance, insulin helps maintain sugar levels in the blood. For contractile functions, proteins allow muscle cells to move by contracting them. In immunological functions, proteins fight against foreign invaders. In transport purposes,...