Cellular Structure

Nucleus  The control center of the cell

Nuclear Membrane  Separates the nucleus from the cytoplasm.  Controls what enters or leaves the nucleus.  Has tiny openings called pores.

Nucleolus  Makes ribosome's and stores messages from the chromatin for future use.  Visible when cell is not dividing  Contains RNA for protein manufacture

Chromatin  Determines cell activities and carries on the hereditary traits of the cell.

 Chromosomes - Usually in the form of chromatin - Contains genetic information - Composed of DNA - Thicken for cellular division - Set number per species (i.e. 23 pairs for human)

Cytoplasm  The watery fluid which contains the materials which enter the cell.

Organelles  Little, tiny structures in the cell performing specific activities.

Mitochondria  The “powerhouse” of the cell.  They create food to obtain energy for cell activities.

The cristae greatly increase the inner membrane's surface area. It is on these cristae that food (sugar) is combined with oxygen to produce ATP - the primary energy source for the cell.

Ribosomes  Makes proteins in the cell. “Protein factories”.

Endoplasmic Reticulum (ER)  A system of canals which transport substances to the inside of the cell.  It is also a chemical producer.

Golgi Apparatus  Package proteins for storage and secretion from the cell.  Creates lysosomes

Lysosomes  Digest worn out or unneeded cells and cell parts. Encloses the materials and bacteria in food vacuoles.

Centrioles  Paired structures in animal cells which help in cell division.  Only visible in animal cells, still in plant cells, but you can’t see them.

Vacuole  Stores food, water, and wastes. Much bigger in plant cells.

Plastids (Chloroplasts)  Found only in plant cells. Absorbs sunlight in the process of photosynthesis.

Cell Membrane  Controls what enters and leaves the cell. It contains the cell contents and protects the cell.  composed of lipids  hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward. Also called lipid bilayer.

Cell Wall  Thick, outer wall surrounding plant cells. Helps support and protect the plant cell.

Specialized Structures  Cilia and flagella are often present on cells that provide locomotion.

Microtubules  Provide shape and movement through the cytoplasm

Specialized Organelles found in Plants  Plastid :Found in plants Stores food or pigments  Cell Wall: Found in plants o Supports and protects the cell  Vacuole: Much larger in plant cells. Stores enzymes and waste products

Specialized Organelles only found in animal or protist (unicellular organisms –fungi) cells  Centriole: Found in animal cells and some protists. Protein fibers that aid in cell division  Cilia: Hair-like microtubules attached to the plasma membrane that often help in movement