Eukaryotic Cell Structure Chapter 7.3

I. CELLULAR BOUNDARIES Plasma/Cell Membrane – Selectively permeable – Chapter 7.2 (phospholipid bi-layer) Cell Wall – Fairly rigid – Only found in plant cells – Made of carbohydrate called cellulose

II. NUCLEUS AND CELL CONTROL Nucleus – Leader of cellular activities – “brain” of a cell – Contains chromatin Strands of DNA Nucleolus – Prominent organelle inside the nucleus

II. NUCLEUS AND CELL CONTROL Ribosomes – Sites of protein synthesis according to DNA’s directions – Made of RNA and protein – Most are made in the nucleus, and leave to go to the cytoplasm and endoplasmic reticulum Cytoplasm – Clear, gelatinous fluid inside a cell – Used to help cell maintain shape and to protect organelles within the cell.

Ribosome

III. ASSEMBLY, TRANSPORT AND STORAGE Endoplasmic Reticulum – Site of cellular chemical reactions – Most ribosomes are located on this organelle “Rough-Endoplasmic reticulum” – A series of highly folded membranes in the cytoplasm Similar to an accordian

Endoplasmic Reticulum

III. ASSEMBLY, TRANSPORT AND STORAGE Golgi Apparatus – Flattened stack of tubular membranes – Modifies proteins – Sorts proteins into – packages and packs – them into vesicles Then are sent to appropriate “destination” within or outsidE the cell

III. ASSEMBLY, TRANSPORT AND STORAGE Vacuoles – Membrane bound compartments in a cell – Used for temporary storage of materials in a cell Food, enzymes, waste, etc. – 1 large in a plant cell – Many small in an animal cell Lysosomes – Organelles that contain “digestive” enzymes – Digest excess or worn out organelles, virus, bacteria, etc.

Lysosomes Come from Golgi

IV. ENERGY TRANSFORMERS Chloroplasts – Capture light energy and convert it into chemical energy (glucose) – Found in plant cells – Double membrane organelle – Inside contains stacks of thylakoid discs called a “grana” – Fluid that surrounds these grana is called “stroma”

Chloroplasts

Mitochondria

Cilia vs. Flagella