Structures and Organelles

ObjectivesIdentify parts of eukaryotic cellCompare plant and animal cells

Nucleus Contains most of Cell’s DNA (blueprints) for the

cell. Nucleus is surrounded by nuclear membrane…

allows substances to pass in and out of the nucleus.

Chromatin is spread throughout the nucleus. It is a DNA attached to protein complex.

Nucleolus: Center of the nucleus, involved in the transcription of RNA

Ribosomes

Ribosomes manufacture proteins for the cell.

Made of RNA and Protein Nucleolus is the site of Ribosome

production

Endoplasmic Reticulum

Is a membrane system of folded sacs and inter connected channels that serve as site for protein and lipid synthesis. Also called ER

Rough ER has ribosomes attached to its membrane

Smooth ER has no ribosomes attached.

Golgi Apparatus (Bodies)

Is a flattened stack of membranes that modifies, sorts, and packages proteins into sacs called vesicles.

Vacuoles

Storage facility for cell. Can store food, enzymes, and waste products.

Animal cells usually do not have vacuoles…. Why?

Lysosomes

Used to digest excess or worn-out organelles and food particles. “garbage men” of cell.

Centrioles

Centrioles are made of microtubules. Function during the division of a cell.

Mitochondria

Energy generators of the cell. Converts food particles into useable

energy. Has an outer membrane and a inner

membrane.

Chloroplasts

Found in plant cells only Convert light energy to chemical

energy through photosynthesis.

Cell Wall

The cell wall is a thick, rigid, mesh of fibers that surrounds the cell outside the plasma membrane. Gives cell support.

Made of cellulose.

Cilia and Flagella Some eukaryotic cells have cilia or flagella that

project outside the plasma membrane. Cilia are hair-like and larger in number than

flagella. Flagella are whip-like and there are only one or

two per cell.

Cytoplasm and Cytoskeleton

Cytoplasm: The cytoplasm is the gel-like substance residing within the cell membrane holding all the cell's internal sub-structures (called organelles), outside the nucleus.

Cytoskeleton:The cytoskeleton is a cellular scaffolding or skeleton contained within a cell's cytoplasm and is made out of protein.

Cell Membrane

Cell membrane:The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment