A Tour of the Cell

Plant Cell

Cells

• Eukaryotic cells, including plant and animal cells, contain a nucleus and organelles

• Plant cells contain a cell wall, chloroplasts and other organelles

• Animal cells contain mitochondria and other organelles

• Prokaryotic cells do not include a nucleus or specialized organelles, include bacteria

• See Figs 7.7 and 7.8

The Nucleus

• Found only in eukaryotic cells• Pores in the nuclear envelope allow for

exchange of materials between nucleus and cytoplasm

• Contains genetic material, DNA• Contains a nucleolus, site where parts of

ribosomes are produced• See Fig. 7.9

Nucleus

Ribosomes

• Free ribosomes (ribosomes in cytoplasm)

• Bound ribosomes (ribosomes attached to endoplasmic reticulum)

• Both carry out protein synthesis

• See Fig. 7.10

Endomembrane System

• Many membranes are interrelated directly through physical continuity or indirectly through transport vesicles

Endoplasmic Reticulum

• Smooth E.R. (no ribosomes attached), synthesizes steroids, metabolizes carbohydrates, stores calcium, and detoxifies liver cells

• Rough E.R. (has ribosomes), manufactures proteins for secretion

• Fig 7.11

Endoplasmic Reticulum

Golgi Apparatus

• Finish, sort, and “ship” many products of the cell

• Synthesize macromolecules

• Store and export products of E.R.

• Fig 7.12

Golgi Apparatus

Lysosomes

• Digestive compartments

• Recycle monomers from cell macromolecules

• Digest substances ingested by phagocytosis

• Fig 7.14

Vacuoles

• Storage compartments

• Animal cells have food vacuoles

• Plant cells have contractile vacuoles

• Function to provide waste disposal, cell elongation, and protection

• Fig 7.15

Peroxisomes

• Consume oxygen in various metabolic functions

• Produce hydrogen peroxide as a waste product and then converts it to water

• Fig 7.17

Mitochondria

• Sites of cell respiration in eukaryotic cells

• Uses energy to restock cellular supply of ATP

• Fig 7.18

Mitochondria

Chloroplasts

• Contain chlorophyll and other pigments which function in photosynthesis

• Found only in plant cells

Fig.7.19

Cytoskeleton

• Provides structural support

• Cilia and flagella aid in mobility

• Intermediate filaments support cell shape and fix certain organelles in place

• Table 7.2

Extracellular Matrix

• Found in animal cells

• Function in support, adhesion, movement, and development

• Consists of protein fibers and a proteoglycan complex attached to the cell membrane

• Fig. 7.30

Websites

Test Yourself On Identifying the Parts of CellsGo to http://www.discoverbiology.com/cells/welcome.htm

Click on “Self Test” On the left side of the screen.Try the “Drag and Drop” tests 6.2a, 6.2b & 6.2c

Go tohttp://www.sigmaxi.org/amsci/articles/99articles/Hoppert.htmlRead the article and look at the illustrations.

More Websites

http://www.cellsalive.com