Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers



  1. What are hydrophobic
    molecules (or hydrophobic
    molecular regions)? What are
    hydrophilic molecules? How
    can they be characterized in
    relation to their polarity?


Hydrophobic molecules are those that


have little or in water (hydro = water, no propensity to dissolvephobia = fear). (^)
Hydrophilic molecules are those that
have great propensity to dissolvewater (philia = friendship). in
Water is a polar suRemembering the rule that “eqbstance. (^) ual
dissolveshydrophobic substances ar equal” one can coe non-polarnclude that
molecules while hydrophilic molecules
are polar molecules.



  1. Are organic solvents like
    benzene and ether polar or
    non-polar substances?


Benzene and the ethers are molecules
without electricallythus they are non-polar s charged portions aubstances. nd



  1. Regarding solubility, how
    are lipids classified?


Fats and oils are hydrophobic moli.e., they are non polar and insoluecules,ble in


water. with a large non-polar extLipids in general are moleculension and soes (^)
they are soluble in non polar solvelike benzene, ether and chloroform.nts,
There are some amphipathic lipids, i.lipids whose molecules have a e.,
hydrophilic portion, like the
phospholipiof being dragged by water, ads, giving them the propertynd a
hydrophobic portion (non polar).



  1. What is meant by
    saturation or unsaturation of
    oils and fats?


When it is said that a triglycerisaturated it means that in its moleculde is (^) e
the carbon chaimaximum capacityn is bound in its to hydrogens, i.e., (^)
there are no double or triple bbetween carbons. These saturatedonds
molecules are generally solid fats at
normal temperature.
Unsaturated triglyceride molecules are
those in bonds between carbwhich there are double or tripleons and so they do
not accomplish their maximum capacity
of hydrogenation. Tmolecules in general are hese unsaturateoils, liquid atd (^)
normal temperature.
The terms saturated refer then to the saturationor unsaturated of the
carbonic chain by hydrogen atoms.
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