Page 120 - The Miracle in the Cell

THE MIRACLE IN THE CELL
Pinocytosis Exopinocytosis

Nutrient
a

Lysosome

Lysosomes
surrounding
the vesicle
b

Figure 6.8 Figure 6.9
Pinocytosis seen in an amoe- a) Substances are removed from the cell by the fusion
ba, a single-celled organism. of a vesicle formed within the cell with the cell mem-
The substance taken inside is brane.
digested with lysosomes, b) Necessary substances are taken into the cell with
which contain digestive the help of a vesicle formed from the cell membrane.
enzymes.

Perfect Cooperation and Harmony
Trillions of cells in your body work together in amazing harmo-
ny. Your hair strands all grow at the same rate because the skin cells
in your head cooperate with each other.
This sensitive relationship is carried out by special proteins and
projections resembling hooks found within the cell membrane, which
facilitate communication among different cells. These mechanisms
start to form while you were still a fetus in your mother's womb.
During cell division, some cells suddenly start to produce different
proteins in a way not yet known. As a result of these different pro-
teins, cells with structural differences start to appear. The cell mem-
brane is also affected: Hook-like projections start to form on its outer

118