why gelatin forms and why gelatin remains as a liquid?
can anyone explain? i need it for my lab report in AP biology.
- 1 decade agoFavorite Answer
Not sure what you mean here exactly Rose, but gelatin is made from long moleclues (like spaghetti!) and when it is dissolved in hot water these "threads" of gelatine swim and move around in the solution. When the temperature drops, the "threads" start wrapping around each other as they can get closer - so you see the gelatin solution getting thicker. At a certain temperature, the "threads" wrap around each other and stick to each other in a kind of spiral. They are held in that position by electrical charges on the gelatine molecule in a similar way to north and south poles of a magnet. At this point you will notice the gelatin solution will have formed a jelly. As the "threads " are long, the formed spiral can compress and open - just like a spring does, a real jelly is also elastic and can wobble.
To get more complicated, the spiral is held in position because the gelatine is made from a sequence of amino acids (all proteins are made from amino acids!) which ha the smallest amino acid (glycine) sit nect to the largest amino acid (hydroxproline). This makes for a twisted "thread" rather than a straight line. When two or three "threads" come near to each other when the temperature in the solution drops, they arrange themselves into this twisted shape - in other words a helix.
Wen th jely is warmed up, the "threads" gain enough energy to bounce around and break free of ach other - so the jely melts.
Hope that helps!