30 Seconds 10 Time’s Up! 3 Minutes 1 Minute 4 Minutes 1 2 5 2 Minutes Bellringer 9-19 What do you think this cartoon is about? What do you think is happening? 30 Seconds 10 Time’s Up! 3 Minutes 1 Minute 4 Minutes 1 2 5 2 Minutes 8 9 7 6 4 3

Cells

Cells

Examples of Cells Amoeba Plants Bacteria Red Blood Cell Nerve Cell

Cells The Building Blocks of Life The cell is the smallest unit capable of performing life functions.

Cell Trivia The average human being is composed of around 100 Trillion individual cells!!! It would take as many as 50 cells to cover the area of a dot on the letter “i”

History of Cells 1665- English Scientist, Robert Hooke, discovered cells while looking at a thin slice of cork (bark of tree) He described the cells as tiny boxes or a honeycomb He thought that cells only existed in plants and fungi

1673- Anton von Leuwenhoek, invented the microscope and observed pond scum and discovered single celled organisms He called them “animalcules” He also observed blood cells from fish, birds, frogs, dogs, and humans Therefore, it was known that cells are found in animals as well as plants

More history… 1838- German Botanist, Matthias Schleiden, concluded that all plant parts are made of cells 1839- German physiologist, Theodor Schwann, who was a close friend of Schleiden, stated that all animal tissues are composed of cells.

The Cell Theory 1. All organisms are composed of one or more cells.

2. The Cell is the smallest working unit of living things.

3. All cells come from pre-existing cells through cell division. Francesco Redi did first experiments to disprove spontaneous generation – Life comes from life - biogenesis

Compound Light Microscope Use in class Compound –Eyepiece (10x) times objective lens 10x X 4x=40x 10x X 10x=100x 10x X 40x = 400x

The Electron Microscope Biggest magnification (X 2,000,000) 2 types (SEM and TEM)

Number of Cells in an organism Unicellular – composed of one cell Multicellular- composed of many cells that organize

Two basic cell types 1. Prokaryotes- ONLY bacteria, one celled, lack a nucleus or membrane-bound organelles

Prokaryotes Contains DNA Cell membrane & cell wall

2. Eukaryotes- (Like U-you) all other living things (plants, animals & fungi), have a nucleus and membrane-bound organelles. May be unicellular or multicellular

Eukaryotic Cell Contain 3 basic cell structures: Nucleus Cell Membrane Cytoplasm with organelles

Two Main Types of Eukaryotic Cells Plant Cell Animal Cell

“Typical” Animal Cell

“Typical” Plant Cell

Plasma (Cell) Membrane Boundary between the internal and external environment of the cell. Controls what goes in & out of cell

Supports and protects the cell. Cell Wall Inflexible structure composed of cellulose, found only in PLANTS and bacteria. Supports and protects the cell.

Contains DNA and controls cell functions.The “brain” of the cell. Nucleus Contains DNA and controls cell functions.The “brain” of the cell.

Organelles “Little Organs” Each has specific functions Found throughout cytoplasm

Nuclear (envelope) Membrane Porous membrane surrounding the nucleus.

Clear, jelly-like fluid in cell. Where organelles are. Cytoplasm Clear, jelly-like fluid in cell. Where organelles are.

Endoplasmic Reticulum(E.R.) Makes lipids (fats) delivery system - manufactures and transports. Smooth and rough

E.R. Rough ER has ribosomes on the surface. Smooth ER does not have ribosome attached

Ribosomes Make proteins Each cell contains thousands Found on ribosomes and floating throughout the cell .

Golgi Apparatus (Body) Packaging and shipping protein (like the UPS)

Vacuoles Plants have single large vacuole. Stores water

Vacuoles Animals have many small ones store food, enzymes

Contain digestive material to breakdown old parts, bacteria and waste. Lysosomes Contain digestive material to breakdown old parts, bacteria and waste.

“Mighty” Mitochondria “Powerhouse”, makes energy for cell. Site of cellular respiration (converts food into usable energy)

Found only in plants - makes food Chloroplasts Found only in plants - makes food Changes the sun’s energy into chemical energy (photosynthesis). Contains chlorophyll (gives plants green color)

Involved in cell division Centriole Involved in cell division Only animal cells!

Ribosomes Each cell contains thousands Make proteins Found on ribosomes, nuclear envelope & floating throughout the cell