Looking Inside CellsSection 1-3

• The cell wall protects and supports the plant cell.

• The cell membrane controls what enters and leaves the cell.

•The nucleus is the cell’s control center. It directs all of the cell’s activities.

Three parts:

1. Nuclear membrane

2. Nucleolus

3. Chromatin (DNA)

• The cytoplasm is the region between the cell membrane and the nucleus. It is a clear, thick, gel-like fluid.

• Mitochondria produce most of the energy needed by a cell.

• Endoplasmic reticulum is a maze of passageways that carry proteins and other materials from one part of the cell to another.

• Ribosomes produce proteins in the cell.

Endoplasmic reticulum

Ribosome

• The Golgi bodies receive proteins and other newly formed materials from the endoplasmic reticulum, package them, and distribute them to other parts of the cell.

• Chloroplasts capture energy from sunlight and use it to produce food for the cell. They are only found in autotrophic organisms.

Chloroplasts

• Vacuoles store food, water, waste products and other materials needed by the cell. Plant cells have large vacuoles.

• Lysosomes release chemicals that break down large food particles into smaller ones.

• Bacterial cells do not have a nucleus.

• Cells in multicellular organisms are often quite different from one another.

• Specialized cells are found only in multicellular organisms.