Eukaryotic Cell Structure Objectives: 4.0 Describe similarities and differences of cell organelles, using diagrams and tables 4.2 Distinguishing between prokaryotic and eukaryotic cells

In Your Groups: Make a list of what things you think the inside of a cell might contain, and what those things might do.

Organelles: “little organs”; structures found in cells that carry out specific functions Cell is divided into 2 main parts: Nucleus: the part of the cell that contains nearly all the cell’s DNA and coded instructions for making proteins and other important molecules Cytoplasm: the portion of the cell outside the nucleus

Parts of the Nucleus: Nuclear envelope – Chromatin - 2 membranes surrounding the nucleus Contains pores (“nuclear pores”) which allow passage of material into and out of the nucleus Chromatin - Granular material USUALLY spread throughout the nucleus Consists of DNA bound to protein

Parts of the Nucleus (cont.): Chromosomes – Threadlike structures that contain genetic information passed to the next generation Condensed chromatin Nucleolus – Small dense region of the nucleus Where the assembly of ribosomes begins

Organelles in the Cytoplasm: Ribosomes – Small particles of RNA and protein found throughout the cytoplasm Follow instructions from the nucleus to make proteins

Organelles in the Cytoplasm (cont.): Endoplasmic reticulum (ER) – An internal membrane system Assembles lipid (?) components of the cell membrane Also assembles proteins and other materials exported (?) from the cell Two types: Rough ER – protein synthesis; ribosomes on surface make it “bumpy” Smooth ER – synthesize membrane lipids; detoxify drugs

Organelles in the Cytoplasm (cont.): Golgi apparatus – Receives proteins produced in rough ER Function: modify, sort, and package proteins and other materials for storage in the cell or secretion outside the cell Lysosomes – Small organelles filled with enzymes Digest or break down lipids, carbohydrates, and proteins, for use by the cell Break down “worn out” organelles

Organelles in the Cytoplasm (cont.): Vacuoles – Saclike structures that store materials (water, salts, proteins, and carbohydrates) More important in plant cells Mitochondria Convert chemical energy stored in food into compounds used by the cell In humans, they COME FROM MOM (from the cytoplams of the ovum – egg cell)

Organelles in the Cytoplasm (cont.): Chloroplasts – NOT found only in plants, but found in ALL plants. Capture the energy from sunlight and convert it into chemical energy (What is this process called?) **Mitochondria and chloroplasts contain DNA molecules.

Organelles in the Cytoplasm (cont.): Cytoskeleton – Protein filaments that provide structure or shape for the cell, and aid in movement. Centrioles – Located near the nucleus Help organize cell division NOT found in plant cells

DCL Assignment: Draw, color, and label: A plant cell An animal cell Which structures are similar, and which are different? Create a flowchart that describes the steps by which proteins are made in the cell.