Cell Structure & Function
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Transcript of Cell Structure & Function
Cell Structure & Function
http://koning.ecsu.ctstateu.edu/cell/cell.html
Cell Theory
• All living things are made up of cells.
• Cells are the smallest working units of all living things.
• All cells come from preexisting cells through cell division.
Definition of Cell
A cell is the smallest unit that is capable of performing life
functions.
Examples of Cells
Amoeba Proteus
Plant Stem
Red Blood Cell
Nerve Cell
Bacteria
Two Types of Cells
•Prokaryotic
•Eukaryotic
Prokaryotic
• Do not have structures surrounded by membranes
• Few internal structures
• One-celled organisms, Bacteria
http://library.thinkquest.org/C004535/prokaryotic_cells.html
Eukaryotic• Contain organelles surrounded by membranes• Most living organisms
Plant Animal
http://library.thinkquest.org/C004535/eukaryotic_cells.html
“Typical” Animal Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
http://waynesword.palomar.edu/images/plant3.gif
“Typical” Plant Cell
Cell Parts
Organelles
Cell Membrane
• Outer membrane of cell –Contains the cell contents–Controls what gets in and out of the cell–Is selectively permeable
http://library.thinkquest.org/12413/structures.html
Nucleus
• Directs cell activities- the “Control Center”• Contains genetic material – DNA• Usually the easiest organelle to see under a microscope
ADD
THE
LABELS
Cytoplasm
• Gel-like mixture
• Surrounded by cell membrane
Endoplasmic Reticulum• Moves materials around
in cell- the “Assembly line or Roads”
• Smooth type: lacks ribosomes
• Rough type (pictured): ribosomes attached to surface
http://library.thinkquest.org/12413/structures.html
Ribosomes• Each cell contains
thousands• Make proteins• Found on RER &
floating throughout the cell
http://library.thinkquest.org/12413/structures.html
Mitochondria
• Cellular respiration occurs here to release energy for the cell to use
• “Power plant” of the cell
http://library.thinkquest.org/12413/structures.html
Golgi Bodies
• Protein “packaging plant” or “shippers”
• Coats proteins and other materials so they can move different location inside/outside of cell
http://library.thinkquest.org/12413/structures.html
Golgi Apparatus
Lysosome• The “Clean-up Crew”• Filled with enzymes that
break apart molecules that are small enough for cell to use
• Get rid of wastes “garbage disposal”
• Destroy old cells/organelles; “suicide sacs”
http://library.thinkquest.org/12413/structures.html
Lysosomes
• Tay-Sachs disease occurs when the lysosome is missing the enzyme needed to digest a lipid found in nerve cells.– As a result the lipid accumulates and nerve
cells are damaged as the lysosome swells with undigested lipid.
Centriole• Aids in cell division• Only in animal cells
Vacuoles• Large central vacuole
in plant cells• Many smaller
vacuoles in animal cells
• “Storage container” for water, food, wastes, etc.
Plant Cell Features
• Unique Features of Plant Cells – Plant cells have three structures that animal
cells lack: • a cell wall• Chloroplasts• Large vacuole
Chloroplast
http://library.thinkquest.org/12413/structures.html
• Found in plant cells
• Capture energy from the sunlight and convert it into chemical energy…PHOTOSYNTHESIS!
• Green in color because of chlorophyll, a green pigment
Cell Wall• Found in plant and
bacterial cells• Rigid, protective
barrier that provides support
• Located outside of the cell membrane
• Made of cellulose (fiber)
Quick Review• Which organelle is the control center of the cell?
Nucleus
• Which organelle holds the cell together?Cell membrane
• Which organelles are not found in animal cells?Cell wall, chloroplasts
• Which organelle helps plant cells make food?Chloroplasts
• What does E.R. stand for?Endoplasmic reticulum
Elodea Cells
http://carnegieinstitution.org/first_light_case/horn/lessons/images/chlorop.jpg
Nucleus
Plasma Membrane
Cytoplasm
Cheek Cells Stained with Methyl Blue
http://faculty.kutztown.edu/friehauf/science_outreach/cheek_cells_005.jpg