Page 174 - The Miracle in the Cell

THE MIRACLE IN THE CELL

Cell wall
Plasma
membrane
Vacuole

Vesicle
Golgi body

Endoplasmic
reticulum
Rough endoplas-
mic reticulum
(with ribosomes)
Chloroplast Nuclear
membrane
Mitochondrion Nucleolus Nucleus
Nucleoplast

Figure 10.1 b) Plant cells and the
a) General diagram of a plant cell chloroplasts within them

Energy from the Sun to Nutrients

The Sun is the primary source of energy for life on Earth, though
humans and animals cannot use this energy directly. The energy used
by our cells is in reality solar energy transferred to us through plants.
When we drink tea with sugar, actually we are drinking in energy
from the Sun. The bread we eat has a large portion of solar energy. The
strength in our muscles is really nothing more than a different form of
solar energy. The heat that arises from a burning piece of wood is just
transformed solar energy. The energy you use in reading this book
again derives from energy from the Sun.
The energy source of plants and animals is the same: solar ener-
gy, transformed, as mentioned earlier, by photosynthesis.
Plant cells convert energy they obtain from sunlight into chemi-
cal energy and store it in very special ways in nutrients. Actually, not

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