Common Cell Traits

Eukaryotic Cells

Cells with a nucleus.  Typically, they are called plant and animal cells.

Prokaryotic Cells

Cells without a nucleus.  Bacteria are all prokaryotic.

Cell Organization

Cells are organized and they have organelles that function for the benefit of the cell.

From Cell to Organism

Magnifying Cells

Development of the Cell Theory

• Cell membrane, cytoplasm, and hereditary material (DNA and RNA)
• Cells come in many different shapes and sizes.
• Size and shape relate to a cell’s function.

Eukaryote

• Have membrane-bound organelles (cell parts that have particular functions).

• Are complex cells and generally make up organized organisms (higher order organisms).
• Can be unicellular, but are mostly found in multi-cellular organisms.
• Domain Eukarya: Kingdoms: Protista, Fungi, Plantae, and Animalia.

Prokaryote 

• No membrane-bound organelles (except chloroplasts which are found in photosynthetic bacteria like cyanobacteria).

• They are simple cells all unicellular.
• Domains Bacteria and Archaea: Kingdoms: Eubacteria and Archaebacteria.

Cell Structure

• Cell Wall: tough, rigid outer covering that protects the cell and gives it shape.

• Can be found in plants, algae (plant-like protists), fungi, and bacteria.
• 

• Cell Membrane: Regulates the interactions between cell and environment, protective layer around all cells.

• Semi-permeable/selectively permeable

• Cytoplasm: gelatin-like substance which surrounds all internal organelles.  

• Many important chemical reactions take place in cytoplasm.

• Cyto-skeleton: structural framework made up of protein (thin, hollow tubes and solid fibers).

• Enable some cells like Amoeba to move
• Helps the cell maintain or change shape

Internal Cellular Organelles

• Nucleus: Directs all cell activities and encodes instructions (blueprints) for all cell operations.

• Director or boss of the cell
• DNA and RNA are packaged into chromosomes.

• Nucleolus: Found inside the nucleus.

• Assistant director
• Makes ribosomes

• Chloroplast: Green organelle found in plant cells, algae, and in photosynthetic bacteria.

• Contains the pigment chlorophyll
• Chlorophyll captures sunlight and the process, photosynthesis, takes place in the chloroplast.

• Mitochondrion (Mitochondria - pl.): Processes and releases stored energy from carbohydrates/food in a process called respiration.

• Powerhouse of the cell, provides energy for the cell.

• Ribosome: Small structures that make proteins for the cell.

• Found as free ribosomes (in cytoplasm) and on Rough Endoplasmic Reticulum (RER), ribosomes make RER rough.

 “Ribs” = protein

• Endoplasmic Reticulum (ER): Series of folded membranes that move material around the cell like a conveyor belt.

• Found as rough, (RER) has ribosomes or smooth, (SER) has no ribosomes.

• Golgi Bodies: Stacked, flattened membranes that move materials to the outside of the cell.

• Sort and package materials like proteins and ship out of cell.
• Uses vesicles (vehicles) to transport
• UPS/Fed-ex

• Vacuole: Storage areas in cells (water, wastes, food, and other materials).  

• Larger in plant cells than in animal cells.  Called central vacuole.

• Lysosome/Peroxisome: Recycling organelles that contain digestive enzymes/chemicals  that help break down food molecules, cell wastes, and worn-out cell parts.

• Movement Structures:  Structures that allow cells to move from one place to another.

• Cilia, flagella(pl.), pseudopods, pili(pl.)

Cell --->Tissue--->Organ--->Organ System--->Organism

• Cell: Basic unit of structure and function.
• Tissue: A group of similar cells that perform the same function.
• Organ: A structure made up of two or more different types of tissues that work together.
• Organ System: A group of organs working together to perform a certain function.

Microscopes

• Compound Light microscope - has 2 or more lenses.
• Dissecting microscope - sees detail of large objects
• Electron Microscope - uses electrons to magnify up to a million times

• Transmission electron (TEM) - sees inside of cells with detail
• Scanning electron (SEM) - sees the outside of cells with detail