Cells

Part I

Prokaryotes vs Eukaryotes

Cell Theory Statements

Schleiden SchwannVirchow

Cells are the basic unit of organization in all living things

All living things are camposed of one or more cells

All cells arise from pre-exsiting cells

Cell Types

• Two cell types that exist– Prokaryotes: unicellular– Eukaryotes: multicellular

Prokaryotes

• Single celled organism

• No true nucleus

• Does contain genetic information

• No membrane bound structures

• Bacteria

Eukaryotes

• Cell contains a true nuclues

• Does contain membrane bound structures

• Found in multi-cellular organisms

Unicellular vs Multicellular

One celled

Bacteria

No cell structures

SIMPLEORGANISM

Multi-celled

Plants, animals

Contains specialized structures

COMPLEX ORGANISM

THEY BOTH CAN CARRY OUT THEIR LIFE FUNCTIONS DEPENDING ON THE ORGANISM

PROKARYOTES-UNICELLULAREUKARYOTES-MULTICELLULAR

Levels of Organization

organism

Organ sytem

organ

cell

tissue

Cell organelles- plant vs animal

Nucleus

• Control center for the cell

• Contains genetic information DNA/RNA wrapped within chromosomes

• Present in both plants and animal cell

Nucleolus

• Granular structure located inside the nucleus

• Contains RNA and proteins

• Produces ribosomes for the cell

Cell Membrane (Plasma Membrane)

• Surrounds the cell

• Allows the movement of certain material into and out of the cell (semi-permeable)

• Composed of layers

• Found in animal and plant

Cytoplasm

• Liquid substance composed of water, salts, enzymes, organic molecules

• Allows for movement of materials through the cell

Endoplasmic reticulum

• Comes in two varietiesSmooth- transports fats through cell

Rough-transports proteins through cell.Rough because of ribosomes on surface

Ribosomes

• Synthesize proteins for the cell

• Found throughout cell and on rough ER

Mitochondria

• Powerhouse of the cell

• Generates energy (ATP) for cell function through cell respiration

• Found in plants and animal cell

Golgi apparatus

• Sometimes called Golgi bodies

• Processes the synthesized proteins and fats

• Found in plants and animals

Vacuoles

• Storage sites for water and minerals

• Plant cell has a larger vacuole than animal cell

• WHY?

Lysosomes

• Clean the cell of debris or broken down cell material

• THINK OF LYSOL

• Only found in eukaryotic cells

Centrioles

• Found only in animal cells. Not found in all plant

• Used in cell replication and division

Cilia

• Short hairlike projections

• Used to aid in movement of certain cells

(cells lining your trachea, paramecium)

• Not found in eukaryotic plant cells

Flagella (um)

• Whiplike structure in some cells that aid in movement ( protist-euglena, sperm cell)

• Not found in plants

Cell Wall

• Found only in plant cells

• Allows the cell to be rigid

• Made of cellulose

• Give the cell its shape

Chloroplast

• Found only in plant cells

• Site of photosynthesis (plant makes its own food)

• Chloroplasts have a chemical called chlorophyll give a plant their green color. Chlorophyll A and B get activated for photosynthesis

Cytoskeleton• A network of protein fibers that

provides support and shape to the eukaryotic cell. Helps to allow cells move as well– Made up of 3 types of fibers:

• Microtubules helps to maintain shape, and assists in cell division

• Intermediate filaments gives the cell strength

• Microfilaments enables cells to move and divide when necessary. Muscle cells have a lot of these for contraction and relaxation of muscles.