Seed Dispersal

Week 7 Assignment

Tamika Jackson

Professor Jiru

Introduction to Biology

August 15, 2011

1. Why are some fruits sweet and some sour, whereas others have no specific taste?

Fruits like apples, mangoes, guavas and watermelon are sweet in taste while other fruits such as oranges, lemons and raw mango are sour in taste. Each fruit has a different taste but the question asked is why does every fruit have a characteristic taste? It all depends on the chemistry of the fruits because fruits contain different levels of fructose and glucose which will affects their sweetness and contains different levels of acids such as vitamin c/ascorbic acid and citric acid (in lemons and limes) which will determine how sour the fruit is. They contain all sorts of other compounds, vitamins and minerals as well, which will affect how they taste. The taste of a fruit depends on the compounds present in it. A fruit normally contains the materials like cellulose, proteins, starch, vitamins, certain acids, fructose or sugar. These materials are found in mixed form inside the fruit and they have different proportions in different fruits. Fruits of sweet taste have more fructose in them whereas the fruits of sour taste have more acids in them. Some fruits are sweet as well as sour in taste like oranges, as it has almost equal quantities of fructose and acids in it. Normally, the raw fruits have more acids but on ripening the quantity of acids get decreases and the amount of sugar gets increase. I think that this is the main reason why some mangoes are sour in taste but when they are ripened, they become sweet. The chemical changes take place inside the fruit during the process of ripening, due to these changes the amount of sugar increases in fruit and it becomes sweet. I have seen that even two fruits of the same type have different taste like two mangoes or two apples do not have same taste but they are different in taste. The reason behind it is that the same fruit has many...