Introduction to Cells Mr. Hildebrandt - Biology
Early Cytology• Cytology - study of cells• Microscopy – study & use of microscopes.• Early microscopes led to the discovery of cells• Cells were thought to resemble prison cells, hence the name.
The Cell Theory• All living things are made of cells.• Cells are the basic unit of life.• Cell come only from existing cells.
Prokaryotic vs Eukaryotic • Eukaryotic Cells have a nucleus and all membrane bound organelles. • Prokaryotic Cells lack a nucleus and other membrane bound organelles.
The Cell’s JacketCell Membrane – a complex, semi- permeable, double-layered membrane that surrounds the cell.
The Cell’s Cytoskeleton • Microfilaments: scaffolding that resists compression • Microtubules: form centrioles which help mitosis • Cytoplasm: gel like substance, fills cell
Organelles – “little organs”• Nucleus – control center of cell• Nuclear membrane - two layer covering• Nucleolus – site of protein synthesis• Chromatin – complex mixture of DNA & proteins
Organelles – “little organs” • Ribosomes: made of RNA & they assemble proteins • Endoplasmic Reticulum (ER) – network of tubes that process & sort proteins. Two types: 1. Smooth ER 2. Rough ER
Organelles – “little organs”• Mitochondria – “powerhouse” of the cell. Site of cellular respiration.
Organelles – “little organs” Golgi Apparatus – structure that processes and sorts proteins and lipids.
Organelles – “little organs”• Lysosome – structure that helps digest unwanted chemicals and wastes.
Organelles – “little organs” Vacuole – storage bins for the cell; much smaller in animal cells
Structures unique to Plant Cells• Cell Wall – gives cell support by connecting to other cell walls. Controls turgidity.• Chloroplast – green structure that is the site of photosynthesis. Contains chemical chlorophyll.