The document summarizes key aspects of cells. It describes cells as the basic unit of structure and function that can be unicellular or multicellular. It discusses how cells were first discovered and studied using microscopes. Several essential scientists who contributed to cell theory are outlined, including Schwann, Schleiden and Virchow who formulated the cell theory stating that all living things are composed of cells, cells are the basic unit of structure and function, and all cells come from pre-existing cells. The main organelles of cells like the nucleus, mitochondria, chloroplasts and lysosomes are briefly described along with their functions.

1. CELL:ORGANIC
UNIT OF LIFE
jrmguce2011

2. CELL
 basic unit of structure and function
 Can be:
 Unicellular
 Multicellular
 Bodies are cooperative of specialized cells
 Cannot survive for long on their own

3. How do we study cells?
 Invention of lenses (merchants of Europe)
 Combination of lenses led to:
 Telescope
 Microscope*
 17th century: discovery and early study of cells
thru*

4. Invention and Development of
Microscopes
 Anton von Leeuwenhoek
 Dutch biologist
 first to explore things: microscopic view
 Pond water (detailed illustration)

5. ESSENTIAL SCIENTISTS
 Robert Hooke
 English scientist
 Pieces of cork
 Composed of thousands of
chambers
 After 200 years: cells were
also found in other
organisms

6. ESSENTIAL SCIENTISTS
 Robert Brown (1833)
 Matthias Schleiden
 Scottish
 German
 Nucleus
 STATED: all plants are
 Dark structure
made up of cells

7. ESSENTIAL SCIENTISTS
 Theodor Schwann
 STATED: all animals are
made up of cells
 Rudolf Virchow
 German 1855
 Cells arise from the
division of pre-existing
cells

8. The CELL THEORY
 most fundamental discovery: nature
of living things
 forms basic framework
 formulated by Schwann, Schleiden
and Virchow

9.  STATES that:
 ALL LIVING THINGS ARE COMPOSED OF CELLS
 CELLS ARE THE BASIC UNIT OF STRUCTURE
AND FUNCTION
 ALL CELLS COME FROM PRE-EXISTING CELLS

10. Prokaryotic VS Eukaryotic
Cells
 Pro- before
 Eu- true
 Karyon- kernel
 Karyon- kernel
 NO NUCLEUS
 Has NUCLEUS
 DNA: concentrated in a
NUCLEOID
 With cytoplasm
 With cytoplasm
 w/ PM
 w/ PM
 Cytosol

15. ORGANELLES
 NUCLEUS
 contains most of the genes
 averaging about 5µm in dm
 *Nuclear envelope
 Encloses nucleus
 Double membrane (lipid bilayer with proteins)
 20 – 40 nm
 Perforated by pores 100 nm in dm
 pore complex*

16. PARTS OF THE NUCLEUS
 *Nuclear lamina
 netlike array of protein filaments
 maintains the shape of the nucleus
 *Nucleolus
 Site: components of ribosomes are synthesized and
assembled
 Components pass through the nuclear pore to the
cytoplasm*
 Appears as a mass of densely stained granules and
fibers adjusting part of chromatin

19. FUNCTION of NUCLEUS
 information center of the cell
 contains DNA
 control protein synthesis
 By sending molecular messengers: mRNA

21. ORGANELLES
 RIBOSOMES
 Protein factory
 cells with active protein synthesis
 prominent nucleoli
 build proteins: two cytoplasmic locales
 Free ribosomes: cytosol
 Bound ribosomes: for inclusion, transport,
packaging

23. ENDO-MEMBRANE SYSTEM
 Membranes that are related either:
 direct physical continuity
 transfer of membrane segments
 Includes: VAly PLAne GOer






Nuclear Envelope
ER
Golgi Apparatus
Lysosomes
Vacuoles
Plasma Membrane

24. Endoplasmic Reticulum
 more than half the total membrane of cells
 reticulum Greek word for network
 Two types:
 Smooth ER
 Rough ER

25.  Smooth ER
 Smooth walls of the sacs are not
studded with ribosomes
 Functions: SYLIP me car DE DRUP
 Synthesis of lipids
 Metabolism of carbohydrates
 Detoxification of drugs and poison

27.  ROUGH ER
 studded with ribosomes
 FUNCTIONS:
 synthesis of secretory protein
 membrane production (membrane factory)
 synthesis of proteins

31. Golgi Apparatus
 Center of: MWSS




Manufacturing
Warehousing
Sorting
Shipping
 Products from the ER are: SMS
 Modified
 Stored
 Sent to other destinations

32.  flattened membranous sacs- CISTERNAE
 vicinity is concentrated with vesicles
 Golgi apparatus- other ENDOMEMBRANE
organelle CONNECTION
 Parts of GA:
 Cis face
 Receiving part (near ER)
 TV moves materials from ER to GA
 Trans face
 Shipping (vesicles)

33.  manufactures certain macromolecules
 Hyaluronic acid
 glue animal cells together
 dispatches products by Budding of vesicles
 gives molecular tags (phosphate groups)

38. Vacuoles
 membrane bound sacs in a cell
 food vacuole- formed by phagocytosis
 Contractile vacuole
 Pumps out water out
 Central Vacuole- filled with liquid
 Tonoplast
 organic compounds (proteins in seed)
 Disposal sites for metabolic products

39. FUNCTION
Repository of
inorganic ions
Storage of
pigments
Helps to protect
against predators

41. LYSOSOMES
 membrane bounded sacs of hydrolytic
enzymes
 digestion of macromolecules
 works best in acidic medium ~pH 5
 maintains internal pH
 excessive leak of a large number
 leads to AUTODIGESTION

42.  hydrolytic enzymes and lysosomal membrane
 by RER and Golgi Apparatus
 Ex. Lysosomes in an Amoeba
 Exhibits PHAGOCYTOSIS
 Phagein Greek: to eat
 Kytos: vessel
 Food vacuole + lysosome = digests food

43.  AUTOPHAGY
 use of its own HE to digest its own organelles
 Recyle its parts
 happens when it engulfs an organelle
 after digestion
 Organic monomers are returned to the cytosol
 Absence of lysosomes
 accumulation of indigestible substrates
 Pompe’s Disease- glycogen
 Tay Sachs Disease- lipid

46. Other Membrane Organelles
 not part of Endo-Membrane System
 membranes not made by ER
 Free ribosomes and Ribomes of Mitochondria and
Cytoplasm
 contain small amounts of DNA
 semi- autonomous

47. Mitochondria
 power house of the cell
 site of cellular respiration
 Catabolic process that generates ATP*
 number related to cell’s metabolic activity
 1-10µm long
 enclosed by two membranes

48.  Membranes*:
 Outer- smooth
 Inner**- convoluted with infoldings (CRISTAE)
 Inter-membrane space
 Mitochondrial matrix

50. Chloroplast
 found in plants and eukaryotic algae
 site of photosynthesis
 Solar energy – chemical energy
 member of plastids
 Amyloplasts- colorless, stores starch
 Chromoplast- stores pigments
 Chloroplast, xanthophyll, fucoxanthin

51.  contains another membranous system
 THYLAKOIDS
 flattened sacs
 forms GRANA
 bathed with stroma

52. Peroxisomes
 specialized metabolic compartment bounded
by a single membrane
 sontains enzymes that produces* H2O2 as a
by product
 FUNCTION:
 use O2 to break Fatty acids
 detoxify alcohol
 Transferring H2 from the poisons to oxygen

53.  BUT….
 H2O2 is toxic
 but peroxisomes have enzymes that convert it to
water
 grow by incorporation of proteins and lipids
made in the cytosol
 splits into two

54.  Examples:
 Glyoxysomes
 fat storing tissues of plant seeds
 has enzyme that initiates conversion of FA- sugar
 food for the seedling