Notes on Cells Life is Cellular

I. History of Cell Theory A. Microscopes s: merchants invented lenses to assess cloth quality 2. Early 1600s: Hans & Zaccharias Janssen invent the first crude microscope

: Robert Hooke used a light microscope to look at thin slices of cork a. saw tiny compartments b. Name them “cells” 4. Late 1600s: Anton van Leeuwenhoek a. developed high quality lenses and first light microscope b. observed tiny structures in pond water [bacteria] c. “Animalcules”

s: Matthias Schleiden & Theodor Schwann observed many organisms a. Schleiden- plants are made of cells b. Schwann- animals are made of cells 2. Rudolph Virchow: studied cell division, bone marrow, and leukemia a. Concluded all cells come from other cells B. Cell Theory

3. Cell Theory All living things are composed of cells Cells are basic units of structure and function in living things New cells come from existing cells

II. Cell Types Two categories: –Eukaryotes- have nucleus –Prokaryotes- do not have nucleus A. Prokaryotes 1. No nucleus 2. No membrane-bound organelles 3. Simple, first to evolve, smaller in size 4. Examples: all bacteria

B. Eukaryotes 1. Have nucleus 2. Membrane-bound organelles [mitochondria, chloroplasts, nucleus] 3. Complex, evolved after prokaryotes, larger in size 4. Examples: Animals, Plants, Fungi, Protists

III. Boundaries of the Cell Typical cells are 5-50 μm A. Plasma or Cell membrane –thin, flexible barrier around cell

B. Cell wall –strong layer around cell membrane (plants) –serve to give support and structure

IV. CELL ORGANELLES Nucleus Nuclear envelope = nuclear membrane Chromatin Chromosomes Nucleolus Ribosomes Cytoplasm Endoplasmic Reticulum (ER) Smooth ER Rough ER Golgi (Body or Apparatus) Vacuoles Lysosomes Mitochondria Plastids Chloroplasts Leucoplasts Chromoplasts Cytoplasm Microtubules Microfilaments Cilia Flagella Centrioles Cytoskeleton

Nucleus –large structure containing cell’s genetic material and controls cell’s activities Cytoplasm –material inside cell membrane but not including the nucleus Basic Cell Structures

Nucleolus Small, dense region inside nucleusSmall, dense region inside nucleus –Assembles ribosomes that make proteins Nuclear MembraneNuclear Membrane –Double-membrane layer –Many pores

Cytoskeleton MicrotubulesMicrotubules –hollow tubes; “tracks” that organelles use to move –Important in cell division; separate chromosomes –Cilia –Flagella MicrofilamentsMicrofilaments –Give movement & support –Tough, flexible framework –Motor proteins move organelles

Ribosomes Made of RNA in nucleolusMade of RNA in nucleolus Assemble proteinsAssemble proteins “Workers”“Workers”

Endoplasmic Reticulum, “conveyor belt”Endoplasmic Reticulum, “conveyor belt” –Makes cell membrane components –Modifies proteins –rough and smooth Rough ERRough ER –involved in synthesis of proteins –Gets appearance by ribsomes Smooth ERSmooth ER –does not have ribosomes on surface –Makes lipids for cell membranes

Golgi Apparatus “Quality control”“Quality control” Stack of membranesStack of membranes Proteins made by RER move hereProteins made by RER move here Enzymes modify carbohydrates and lipids to proteinsEnzymes modify carbohydrates and lipids to proteins Brings to the cell surface to be secretedBrings to the cell surface to be secreted

Lysosomes “Janitors”“Janitors” Small, filled with enzymesSmall, filled with enzymes Break down lipids, carbohydrates, and proteins into particles the cell usesBreak down lipids, carbohydrates, and proteins into particles the cell uses Break down old organellesBreak down old organelles

Vacuoles “Storage”“Storage” Store H 2 O, salts, proteins, carbsStore H 2 O, salts, proteins, carbs Support structures, like leaves and flowersSupport structures, like leaves and flowers Plants often have a central, large vacuolePlants often have a central, large vacuole Smaller vacuoles called “vesicles”Smaller vacuoles called “vesicles”

Chloroplasts “Solar panels”“Solar panels” Found in plantsFound in plants photosynthesisphotosynthesis Two envelopeTwo envelope membranes membranes

Mitochondria “Power house”“Power house” Release energy from stored foodRelease energy from stored food Use energy to make high-energy compoundsUse energy to make high-energy compounds 2 envelope membranes2 envelope membranes DNADNA Inherited from mom!Inherited from mom! Found in all eukaryotic cellsFound in all eukaryotic cells

Cell as a factory Plasma membrane- “shipping/receiving department” Cytoskeleton- “walls, roof, and beams” Nucleus- “the control center, CEO” Ribosome- “workers” Golgi Apparatus- “Quality control” Mitochondria and chloroplasts- “power sources” Lysosomes- “janitors”

V. Differences between Plant & Animal Cells Plants have/animals don’t: B. Animals have/plants don’t:

VI. Cellular Organization Unicellular- “one cell” 1. more complex as one cell than a single cell of a multicellular organism 2. performs all functions that a multicellular organism does B. Multicellular- “many cells” 1. Cell specialization 2. Interdependent on other cells

C. 5 Levels of Organization » Cells » Tissues » Organs » Organ systems » Organism