CELLS Bill Nye: Cells Discovery Cells

B ASIC S TRUCTURE OF A C ELL

CELL THEORY 1. All living things are made of cells 2. Cells are the basic unit of life 3. Cells come from other cells TED: Cell Theory Cell Theory Song

N UMBER OF C ELLS Unicellular – composed of one cell Multicellular- composed of many cells that may organize into tissues

P ROKARYOTES – T HE FIRST C ELLS No Nucleus Bacteria Simplest type of cell Single, circular DNA

E UKARYOTIC C ELL Contain 3 basic cell structures: Nucleus Ribosomes Cytoplasm with organelles

CELL SIZE

C ELL S IZE AND T YPES Cells must be observed under microscope Three Basic types of cells include : Animal CellPlant Cell Bacterial Cell

W HICH C ELL T YPE IS L ARGER ? _________ > _____________ > ___________ Plant cellAnimal cellBacteria

E XAMPLES OF A NIMAL C ELLS Muscle cellsRed blood cells Cheek cells

E XAMPLES OF ANIMAL CELLS white blood cell red blood cell cheek cells sperm nerve cell muscle cell Amoeba Paramecium

A NIMAL C ELL O RGANELLES Nucleolus Nucleus Nuclear envelope Ribosome (attached) Ribosome (free) Cell Membrane Rough endoplasmic reticulum Golgi apparatus Mitochondrion Smooth endoplasmic reticulum Centrioles

E XAMPLES OF P LANT CELLS Xylem cells Pollen Guard Cells

E XAMPLES OF PLANT CELLS Onion Epidermal Cells Root Hair Cell root hair Guard Cells

P LANT C ELL O RGANELLES

D IFFERENCES BETWEEN PLANT CELLS AND ANIMAL CELLS Animal cellsPlant cells Irregular shape No cell wall Regular shape Cell wall present No chloroplastHave chloroplast Large central vacuole Vacuole small or absent

B ACTERIA C ELLS Contain ONLY essential structures: Plasma membrane Cytoplasm Cell Wall Cilia or Flagella Ribosomes Nucleoid Region

O RGANELLES “Mini Organs” that perform functions for the cell In cytoplasm

1. C ELL /P LASMA M EMBRANE Composed of double layer of phospholipids and proteins Surrounds outside of ALL cells Controls what enters or exits the cell Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains

Found in plants and bacteria Made of carbs Supports and protects cell Cell wall 2.C ELL W ALL 2.C ELL W ALL

Jelly-like substance Holds organelles ALL cells 3. C YTOPLASM cytoplasm

Control center Contains DNA 4. N UCLEUS

5. N UCLEAR E NVELOPE / MEMBRANE Double membrane- surrounds nucleus Controls what exits/enters nucleus Nuclear pores

6. N UCLEOLUS Inside nucleus Makes ribosomes

7. N UCLEAR P ORE Allows certain things to pass through the nucleus

8. C YTOSKELETON Maintains cell shape Made of proteins Microfilaments Microtubules

9. C ENTRIOLES Found only in animal cells Only during cell division Pulls DNA apart

10. M ITOCHONDRION ( PLURAL = MITOCHONDRIA ) “Powerhouse” of the cell Makes Energy (ATP) Has own DNA What type of cell would have the most mitochondria? Mighty Mitochondria!

11. R IBOSOMES Make PROTEINS (protein factories) Attached to the Endoplasmic Reticullum or Free  Workers of the cell!

12. R OUGH E NDOPLASMIC R ETICULUM (R OUGH ER) 12. R OUGH E NDOPLASMIC R ETICULUM (R OUGH ER) Has ribosomes on its surface Makes membrane proteins and proteins for EXPORT out of cell

13. G OLGI B ODIES Look like a stack of pancakes Modify, sort, & package molecules from ER for storage OR transport out of cell Post Office of the cell!

Golgi Animation Materials are transported from Rough ER to Golgi to the cell membrane by VESICLES

14. S MOOTH E NDOPLASMIC R ETICULUM (S MOOTH ER ) No ribosomes Makes cell products that are USED INSIDE the cell Makes membrane lipids (steroids) Detoxifies (Liver )

15. L YSOSOMES Contain digestive enzymes Break down food, bacteria, and worn out cell parts bacteria, and worn out cell parts “Suicide sacs”

16. PEROXISOME Break down Hydrogen Peroxide produced by lysosomes

17. V ACUOLES Storage of waste, water, nutrients Animal cells- small/absent Plant cells- large Central

18. C HLOROPLASTS Plants only Site of Photosynthesis

19. V ESICLE Small, mobile organelles Often used to move chemicals to other locations in the cell where they might be needed

Vesicles

20. C ILIA & F LAGELLA Move cells or move something across the cell surface Cilia-short, many (spirit fingers) Flagella-Long hair-like structure for movement

C ELL M OVEMENT WITH C ILIA & F LAGELLA

C ILIA M OVING A WAY D UST P ARTICLES FROM THE L UNGS R ESPIRATORY S YSTEM

C ELL S IZE Question: Are the cells in an elephant bigger, smaller, or about the same size as those in a mouse?

F ACTORS A FFECTING C ELL S IZE Surface area (plasma membrane surface) is determined by multiplying length times width (L x W) Volume of a cell is determined by multiplying length times width times height (L x W x H) Therefore, Volume increases FASTER than the surface area

C ELL S IZE When the surface area is no longer great enough to get rid of all the wastes and to get in enough food and water, then the cell must divide Therefore, the cells of an organism are close in size

C ELL S IZE Question: Are the cells in an elephant bigger, smaller, or about the same size as those in a mouse? About the same size, but … The elephant has MANY MORE cells than a mouse!