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 outsidEthe 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