The Cell Theory & Cell Structure Chapter 3, sections 1 and 2

The Cell Theory All living things are made of cells Cells are the basic unit of structure & function All cells come from pre-existing cells

Scientists and their Contributions 1655 – Robert Hooke coins the term “cell” after viewing cork under an early microscope  A drawing of Hooke’s cork cells Hooke would have used a microscope like this 

Scientists and their Contributions 1674 – Anton van Leeuwenhoek observes the first living cells under a microscope

Scientists and their Contributions 1838 – Matthias Schleiden determines that all plant tissues are made of cells 1839 – Theodor Schwann determines that all animal tissues are made of cells

Scientists and their Contributions 1855 – Rudolf Virchow asserts that every cell comes from a pre-existing cell

Prokaryotes vs. Eukaryotes CharacteristicProkaryoteEukaryote Outer boundary Cell wall and cell membrane always present Cell membrane always; cell wall sometimes NucleusNOYES

Prokaryotes vs. Eukaryotes CharacteristicProkaryoteEukaryote DNA YES RibosomesYES

Prokaryotes vs. Eukaryotes CharacteristicProkaryoteEukaryote Other organellesNOYES Kingdoms (classification) Eubacteria, Archaebacteria Protista, Fungi, Plantae, Animalia

Prokaryotes vs. Eukaryotes Prokaryotes: cell that does not have a nucleus or any other membrane-bound organelles Eukaryotes: cell that does have a defined nucleus and other membrane- bound organelles

Plants vs. Animals CharacteristicPlantsAnimals Outer boundaryCell wall and cell membrane Cell membrane only NucleusYES

Plants vs. Animals CharacteristicPlantsAnimals DNAYES MitochondriaYES

Plants vs. Animals CharacteristicPlantsAnimals ChloroplastsYESNO VacuolesOne large, central vacuole Many smaller vacuoles throughout

Plants vs. Animals CharacteristicPlantsAnimals Trophic roleautotrophic (producer) heterotrophic (consumer) Kingdom (classification) PlantaeAnimalia

Cells vary between and within organisms. Cells come in all sizes ex: bacterial cells are much smaller than a typical animal cell Some cells may have differences based upon their requirements ex: cells that need to produce lots of energy, like muscle cells, might have more mitochondria (since mitochondria are the “powerhouses” of the cell).

Key Organelles (1) Nucleus – control center of cell; contains deoxyribonucleic acid (DNA); enclosed by a nuclear membrane with pores; only in eukaryotes

Key Organelles (2) Ribosomes – site of protein synthesis some are free- floating, some are attached to rough ER

Key Organelles (3) Endoplasmic reticulum – “highway” of cell; provides path for other substances to travel along; may be smooth (w/o ribosomes) or rough (w/ ribosomes)

Key Organelles (4) Golgi Apparatus – “post office” of cell; modifies and packages protein & lipids before they are sent out of the cell

Key Organelles (5) Mitochondria – “powerhouse” of cell; converts food energy into chemical energy (ATP); has a double membrane and its own DNA (which can be considered evidence of endosymbiosis)

Key Organelles (6) Lysosomes – enzyme-filled sacs that digest cellular wastes

Key Organelles (7) Chloroplast – site of photosynthesis; converts solar/light energy into sugar (glucose); found in plant cells, some bacteria, and some protists; has a double membrane and its own DNA (which can be considered evidence of endosymbiosis)

Key Organelles (8) Vacuoles – storage tank; primarily for water but also holds some minerals and other dissolved solids; plant cells have one large central vacuole while animal cells multiple, smaller vacuoles

Make sure you can… Label the key organelles on a plant and / or animal cell diagram! Compare and contrast: –Prokaryotes and Eukaryotes –Plant and Animal cells