CELL pp. 69-78

LEVELS OF ORGANIZATION

HISTORY Hooke: observed cork

Leeuwenhoek: first to observe living cells

CELL THEORY All living things composed of cells. Cells are basic units of structure and function. Cells come from pre-existing cells

BASIC PARTS OF A CELL Cell membrane Genetic material (DNA) Ribosomes: make proteins Cytoplasm: surrounds the cell’s organelles

Cell membrane Selectively permeable: controls what comes into and out of the cell Made of phospholipids that form a lipid bilayer

Cell membrane has proteins peripheral: attached to the surface integral: embedded in the bilayer

Fluid mosaic model: cell membrane behaves more like a fluid than solid

CELL TYPES Prokaryotic: oldest living cells that lack membrane-bound organelles and are unicellular Eukaryotic: contain a membrane-bound nucleus and organelles

Prokaryotic Cell Prokaryotic

Animal Cell

Plant Cell

Plant cells similar to animal cells since both are eukaryotic Plants also have: A cell wall Chloroplasts: organelles that undergo photosynthesis Large vacuole: stores water