Cells II Cells Part II
Cell Theory The cell is the smallest unit of life. The cell carries out all life processes All organisms are made from one or more cells. CellsTissuesOrgansSystemsOrganism Cells arise from pre-existing cells. DNA in each cell contains all the information necessary to produce offspring
All cells have: Cell membrane Surrounds, contains, protects Cytoplasm “Cell gel” fills interior of cell Ribosomes Help make proteins for cells DNA Contains instructions for cell
Two Categories of Cells Prokaryotes “Before” nucleus Simple structure Bacteria Archaebacteria Eukaryotes True nucleus holds DNA Many cell parts with special functions One cell or multicellular organisms Plants! Animals! Fungi! Single-cell organisms!
Eukaryotic cells are larger and more complex than prokaryotic cells
Eukaryotic cells have organelles that perform special functions: Manufacture cell products Breakdown & maintenance Convert energy Movement, support Communication
Think as you study cell parts: What does it look like? What is its function? What other organelles does it work with? How does the structure of this organelle allow it to do its job? Is it in Animals? Plants? Other?
“Generic” Animal Cell
Boundary / Protection
Cell Membrane: Controls what goes in and out
Cytoplasm / Cytosol: Cell Gel Pancreas cell Cytoplasm / Cytosol: Cell Gel Cytoplasm fills cell Organelles are suspended in matrix
Information
Nucleus: Control Center for the Cell
Contains DNA packaged into chromosomes
Nucleus is connected to important endomembrane structures
Manufacturing
Ribosomes: Workbench for making proteins
Endoplasmic Reticulum: Internal transport system of cell
2 forms of ER: Ribosomes attached to ER give it a rough appearance Rough ER Smooth ER Ribosomes attached to ER give it a rough appearance Helps synthesize proteins Transports proteins within cell Transports Stores calcium Involved in making lipids
Golgi body: Packages and Ships Cell products
Protein Synthesis Making proteins is one of the most important jobs of the cell!
Maintenance
Lysosomes: Clean up crew; Baggies of powerful digestive enzymes get rid of old cell parts, bacteria
Energy production
Mitochondria: Powerhouse of the cell Extract energy from glucose to provide energy for cell functions
Structure and movement
Cytoskeleton Blue - nucleus
3 sizes of fibers form skeleton of cell Produce shape & create movement
Plant Cells
Plant Cell
Plants have specialized organelles not found in animal cells: Rigid cell wall: support Chloroplasts: capture energy from sun Large vacuole: storage (water, sugars)
Chloroplast: Use sunlight to make sugars Photosynthesis
Chloroplasts
Plant Cell Vacuole: Stores water and food
Plant Cell Walls: Support and Protection
A few examples of specialized cells from complex organisms