Cell Discovery and Theory Chapter 7-1

I. Discovery Mid 1600’s

A. Robert Hooke (1665) Looked at cork and saw tiny little boxes Reminded him of rooms in a monastery Called the “little rooms” CELLS

B. Anton Van Leeuwenhoek (1674) First person to use microscope to identify LIVING things Reminded him of “little animals” Named them animalcules

C. Matthias Schleiden (1838) Botanist Concluded all plants are made of cells

D. Theodor Schwann (1839) Zoologist Concluded all animals are made of cells

E. Rudolph Virchow (1855) Virologist Concluded that CELLS COME FROM PRE-EXISTING CELLS

F. Cell Theory Based on findings from 5 scientists All living things are composed of cells Cells are the basic unit of structure and function in living things New cells are produced from pre-existing cells

II. All cells have Cell membranes Genetic Info (DNA/Chromosomes)

III. Two Category of cells- Depending on if they have a nucleus Eukaryotic cells - contain nucleus Prokaryotic Cells- Do NOT contain nucleus

A. Prokaryotic Cells (Bacteria) Smaller and simpler than eukaryotic cells DNA not inside a nucleus-instead floats in cytoplasm 2 of 6 KINGDOMS are prokaryotic Archaebacteria and Eubacteria.

B. Eukaryotic Cells (everything except bacteria) Larger and more complex DNA inside nucleus 4 of 6 KINGDOMS are eukaryotic Plant, animal, fungi and protist

Organelles “Tiny Organs” Ch. 7-2

Cytoplasm Jelly-like substance throughout cells. Contains organelles. Chemical reactions take place here.

Nucleus Largest organelle in eukaryotic cells Contains DNA Controls all cell’s activities

Nucleoplasm Jelly-like substande inside nucleus Similar to cytoplasm of cell Surrounds the genetic material and nucleolus NUCLEOPLASM nucleolus Nuclear envelope Nuclear pores

Nuclear Membrane (Nuclear Envelope) Surrounds the nucleus Controls what gets in/out Allows things in and out through Nuclear Pores NUCLEAR MEMBRANE NUCLEAR PORES

Genetic Material Made of DNA Has directions for making proteins. Eukaryotic cell- in nucleus Prokaryotic cell- in cytoplasm chromatin chromosome

Nucleolus Circular structure inside nucleus Makes ribosomes nucleolus

Ribosomes Makes proteins according to instructions from DNA Found Free in cytoplasm Attached to Rough ER Attached to nuclear envelope ribosomes

Rough Endoplasmic Reticulum Usually attached to nuclear envelope Ribosomes attached to it. Transports proteins made by ribosomes Rough ER- ribosomes attached Smooth ER-no ribosomes attached

Smooth Endoplasmic Reticulum Network of membranes. Manufactures and transports Lipids. Smooth ER- NO ribosomes attached

Golgi Apparatus (Golgi Bodies) Network of membranes Packages and ships proteins

Lysosomes Contains enzymes to breakdown unneeded things in cell. “Suicide sacs”-recycles waste.

Vacuoles Plants a. Stores water. b. Very large Animals a. Stores carbs., lipids, & proteins b. Small

Mitiochondria Makes energy for cell by breaking down glucose. (Cell respiration processes occur both inside and around the Mitochondria.) Bean shaped with many membranes called cristae. Very abundant in muscle cells.

Chloroplast Where Photosynthesis takes place. Makes glucose Green bean shaped Contains green pigment chlorophyll

Cytoskeleton Mesh like material throughout cytoplasm. Supports cell. Scaffolding made of microfilaments and microtubules.

Centrioles Aides in cell division (mitosis) 2 in each cell Composed of microtubules & microfilaments.

Cell Membrane Surrounds cell Regulates what comes in and out of cell. Made of lipids and protein. CELL MEMBRANE

Cell Wall Tough outer covering. Outside of cell membrane Supports and protects cell.

Cillia Used for movement Hair-like Ex: trachea

Flagella Used for movement Whiplike Ex: Sperm

Cell Membrane Endoplasmic Reticulum Nucleus Golgi Body Mitochondria Ribosomes Lysosome