Page 26 - The Cell and Its Components

Plant Cell Chloroplasts

What are chloroplasts?
Chloroplasts are unique structures found in
plant cells that specialize in converting sunlight into
energy that plants can use. This process is
called photosynthesis.

Organelle
Chloroplasts are considered organelles in plant cells.
Organelles are special structures in cells that perform
specific functions. The main function of the chloroplast is
photosynthesis.

Chloroplast Structure
Most chloroplasts are oval-shaped blobs, but they can
come in all sorts of shapes such as stars, cups, and
ribbons. Some chloroplasts are relatively small compared
to the cell, while others may take up the majority of the
space inside the cell.

 Outer membrane - The outside of the chloroplast
is protected by a smooth outer membrane.
 Inner membrane - Just inside the outer membrane
is the inner membrane which controls which
molecules can pass in and out of the chloroplast.
The outer membrane, the inner membrane, and
the fluid between them make up the chloroplast
envelope.
 Stroma - The stroma is the liquid inside the
chloroplast where other structures such as the
thylakoids float.
 Thylakoids - Floating in the stroma is a collection
of sacks containing chlorophyll called the