A Tour of the Cell
Cellular Control Center
NucleusIn eukaryotes the nucleus contains most of the cell’s DNA; the instructions for making important cellular molecules.
Animal Plant
Nuclear Envelope The nucleus is surrounded by a two-layer
membrane called the nuclear envelope.
Nucleolus The nucleolus is a dense region in the nucleus
where ribosomes are assembled.
Support, Storage, and Clean-up
Cytoskeleton The cytoskeleton is a network of proteins that
helps the cell maintain shape and transport materials around the cell.
Centrioles Centrioles cytoskeleton structures found in
animal cells that help organize chromosomes during cell division.
Vacuoles and Vesicles
Vesicles store and move materials between cell organelles, and to the cell surface.
Plant cells store materials (water, salts, and proteins) in saclike structures called as vacuoles.
Vesicle
Vacuole
Moving CargoVesicles are transported around the cell by attaching to the cytoskeleton.
Lysosome Lysosomes are small
organelles filled with digestive enzymes that break down worn-out or damaged organelles.
Building Proteins
Ribosomes One of the most important jobs of the cell is
making proteins. Ribosomes are the protein making machinery.
Endoplasmic Reticulum The endoplasmic reticulum is folded membrane
system with a large surface area.
Rough Endoplasmic Reticulum The rough endoplasmic reticulum assists in
protein formation.
Smooth Endoplasmic Reticulum The smooth endoplasmic reticulum aids in the
formation of complex lipids (e.g. membranes and hormones).
Golgi The Golgi modifies, sorts, and packages proteins
and lipids for storage or transport out of the cell.
Protein Synthesis
Cellular Energy
Chloroplasts
Chloroplasts use the energy from sunlight to make energy-rich food molecules (sugar) in a process known as photosynthesis.
Mitochondria
Mitochondria use energy from food to make high-energy compounds (ATP) that the cell uses to power cellular processes.
Cellular Boundaries
Plasma MembraneThe plasma membrane is a thin flexible barrier that regulates what enters and leaves the cell.
Cell WallPlants, bacteria, fungi, and algae have a tough cell wall made out of cellulose.