Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html

Cell Theory All living things are made of cells. Cells are the smallest units of life. All cells come from other cells. Cells need energy. Cells have DNA that passes to offspring. Cells are made of the same four macromolecules

Cell Theory Scientists Hooke – named cells; viewed “cork” under a microscope Leeuwenhook – saw living cells and called them “animalcules” Schwann – concluded that all animals were made of cells Schleiden – concluded that all plants were made of cells Virchow – determined that cells only came from pre-existing cells

Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

Cell Types Prokaryotes – tiny, simple cells with NO nucleus; always single celled; example: ONLY bacteria Eukaryotes – slightly larger, more complex cells that DO contain a nucleus/organelles; two types (plant and animal); can be single OR multicellular; example: dog, human, tree, (anything living except bacteria)

Prokaryotic Cells/Prokaryotes http://library.thinkquest.org/C004535/prokaryotic_cells.html

Eukaryotic Cells/Eukaryotes Plant http://library.thinkquest.org/C004535/eukaryotic_cells.html

Eukaryotic Cells/Eukaryotes Animal http://library.thinkquest.org/C004535/eukaryotic_cells.html

Identifying Cell Types If it does not have a nucleus, it is a prokaryote. NO = PRO If it has a nucleus, it is a eukaryote. DO = EU Plant cells are always boxy shaped. Animal cells are usually round, but can be any shape. They are never boxy.

In this picture, the black dots are bacteria (prokaryotic cells- too small for a nucleus), the yeast cells are eukaryotes (notice the nucleus) and the scoby is a multicellular fungus. Notice the size differences.

Cell Parts Some of these parts are in ALL cells, but most are only in Eukaryotes.

Cell Membrane ALL cells Outer layer of cells; controls what comes in/out Hydrophobic phospholipid bilayer http://library.thinkquest.org/12413/structures.html

Cell Wall Only Eukaryote Plants and some Prokaryotes (never animal cells) Extra outer layer for support/structure http://library.thinkquest.org/12413/structures.html

Cytoplasm All cells Jelly like substance that fills the cell; site of some chemical reactions

Nucleus Only Eukaryotes Contains DNA and RNA (instructions) to control the cell Surrounded by a nuclear membrane, so the DNA can’t leave (but RNA can)

Nucleolus Eukaryotes Only Dark area inside the nucleus where ribosomes are made from RNA http://library.thinkquest.org/12413/structures.html

Ribosomes All Cells Make proteins Found on Rough ER or floating throughout the cell http://library.thinkquest.org/12413/structures.html

Endoplasmic Reticulum Eukaryotes only Assembles and moves material around within the cell Rough: proteins, covered in ribosomes Smooth: lipids, no ribosomes http://library.thinkquest.org/12413/structures.html

Golgi Eukaryotes Only Package and move materials in or out of the cell (like UPS) Packages are called “vesicles” http://library.thinkquest.org/12413/structures.html

Lysosome Eukaryotes only Digests or destroys anything needed using enzymes (food, old cell parts, viruses, etc) http://library.thinkquest.org/12413/structures.html

Vacuoles Eukaryotes only Storage Very large in plant cells for water storage http://library.thinkquest.org/12413/structures.html

Mitochondria Endosymbiotic Theory Eukaryotes Only Breaks down sugar to produce cell energy (ATP) through respiration Used to be a free-living prokaryote Evidence: same size as bacteria, contains its own circular DNA Endosymbiotic Theory http://library.thinkquest.org/12413/structures.html

Chloroplast Eukaryotic plants only Site of photosynthesis (using sunlight to make sugar) using green chlorophyll Used to be a free-living prokaryote like the mitochondria http://library.thinkquest.org/12413/structures.html

Centriole/Centrosome Eukaryotic Animal Cells ONLY Helps with cell division

Cytoskeleton Eukaryotic Cells only Inner support

Cell Movement All Cells Cell or material movement Cilia = hairs Flagella = tail(s)

Group Project – The ____ is like a _____, because _______. Make analogies for the following organelles Nucleus Nucleolus Endoplasmic reticulum Golgi vacuole Cytoplasm Ribosomes Cytoskeleton Chrolorplast Centriole Cell membrane Lysosomes Mitochondria Cell wall