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OUTLINE OF BIOLOGY-Introduction
Artificial life
Replicas based on digital programs May be silicon computer chip New - DNA chips
Scientific methods
There is no such thing as "The Scientific Method" Scientists use many variations of two basic approaches Two fundamental approaches Question, observation, comparison, description, hypothesis Question, observation, experiment, hypothesis Experiments useful in molecular sciences, like physiology Experiments not always appropriate in other sciences Astronomy, geology, anatomy Retest, verify, confirm -----> theory Not a guess, but a tested, verified and confirmed hypothesis Supported by consistent data, and accurate results of predictions EXAMPLE: the theory of evolution Evolution is as good a fact as any we have in science Insistence on evidence Insistence on testable hypotheses Insistence on repeatability, verification, peer review Data analysis Graphing Database analysis Statistics Validity testing - are observed differences real or chance? Chi square test of confidence
There is no such thing as "The Scientific Method" Scientists use many variations of two basic approaches Two fundamental approaches
Question, observation, comparison, description, hypothesis Question, observation, experiment, hypothesis
Experiments useful in molecular sciences, like physiology Experiments not always appropriate in other sciences Astronomy, geology, anatomy Retest, verify, confirm -----> theory Not a guess, but a tested, verified and confirmed hypothesis Supported by consistent data, and accurate results of predictions EXAMPLE: the theory of evolution Evolution is as good a fact as any we have in science Insistence on evidence Insistence on testable hypotheses Insistence on repeatability, verification, peer review Data analysis
Graphing Database analysis Statistics Validity testing - are observed differences real or chance? Chi square test of confidence
Graphing Database analysis Statistics
Validity testing - are observed differences real or chance? Chi square test of confidence
CELL BIOLOGY
Cells
Organelles - structure and function Membrane bound Nucleus, mitochondria, chloroplasts, lysosomes (Apoptosis) Cell suicide, programmed cell death Endoplasmic reticulum, Golgi apparatus (dictyosome) Non-membrane bound Ribosomes, nucleolus, microtubules (tubulin) Microfilaments (actin), centrioles,
Organelles - structure and function Membrane bound
Nucleus, mitochondria, chloroplasts, lysosomes (Apoptosis) Cell suicide, programmed cell death Endoplasmic reticulum, Golgi apparatus (dictyosome)
Non-membrane bound
Ribosomes, nucleolus, microtubules (tubulin) Microfilaments (actin), centrioles,
Microscopes
Resolution proportional to 1/wavelength of illumination UV and x-rays have short wavelengths, higher resolution Light microscope (LM) 2,000X max magnification Co focal LM - 3D views of living or fixed tissues TEM - transmission electron microscope Killed tissue, ultra thin sections (about 20 nm) Electron beam passed through specimen Internal views up to 1 X 106 magnifications SEM - scanning electron microscope Mostly killed tissue, thick or whole specimens Electron beam scanned over surface of specimen 3D views of surface structure, all in focus Typically magnifications not more than 1 X 104 Insects often seen at about 100x to 500x Black and white only - no colors possible Colors must be added by user - artificial only
Resolution proportional to 1/wavelength of illumination UV and x-rays have short wavelengths, higher resolution Light microscope (LM)
2,000X max magnification Co focal LM - 3D views of living or fixed tissues
TEM - transmission electron microscope
Killed tissue, ultra thin sections (about 20 nm) Electron beam passed through specimen Internal views up to 1 X 106 magnifications
SEM - scanning electron microscope
Mostly killed tissue, thick or whole specimens Electron beam scanned over surface of specimen 3D views of surface structure, all in focus Typically magnifications not more than 1 X 104 Insects often seen at about 100x to 500x Black and white only - no colors possible Colors must be added by user - artificial only
Cell theory
All organisms made of cells All cells come from cells Cells basic units of structure and function Types of cells 6 kingdoms of life Eubacteria = prokaryotic (no nuclei or membrane bound organelles)muramic acid in cell walls Archaea = thermophilic bacteria of hot springs and ocean vents Prokaryotic Unique ribosomal RNA sequences No muramic acid in cell walls Protista = single celled eukaryotes Fungi = heterotrophic eukaryotes with cell walls Animalia = heterotrophic eukaryotes with no cell walls Plantae = autotrophic eukaryotes with cellulose cell walls Cellular pathways - synthesis and metabolism DNA to protein synthesis to packaging to transport to excretion Plasmolysis - cytoplasm of plant cells may shrink away from the wall Cell shrinks if water moves out Water moves out if less concentrated outside of cell Addition of salt to medium can cause plasmolysis Water- a polar molecule Water is positive near the 2 hydrogen’s and negative at the oxygen
All organisms made of cells All cells come from cells Cells basic units of structure and function Types of cells 6 kingdoms of life
Eubacteria = prokaryotic (no nuclei or membrane bound organelles)muramic acid in cell walls Archaea = thermophilic bacteria of hot springs and ocean vents Prokaryotic Unique ribosomal RNA sequences No muramic acid in cell walls Protista = single celled eukaryotes Fungi = heterotrophic eukaryotes with cell walls Animalia = heterotrophic eukaryotes with no cell walls Plantae = autotrophic eukaryotes with cellulose cell walls
Cellular pathways - synthesis and metabolism DNA to protein synthesis to packaging to transport to excretion Plasmolysis - cytoplasm of plant cells may shrink away from the wall Cell shrinks if water moves out Water moves out if less concentrated outside of cell Addition of salt to medium can cause plasmolysis Water- a polar molecule Water is positive near the 2 hydrogen’s and negative at the oxygen
Cell membrane structure
A lipid bylayer with embedded proteins Fluid mosaic model Polar lipid molecules Heads outside (hydrophilic) Tails point inside (hydrophobic) Proteins Trans membrane Channels Na+ (sodium), Ca2+ (calcium) Transporters Embedded Markers, receptors
Cell membrane transport
Passive - diffusion, osmosis No energy required From high concentration to low concentration EXAMPLE: diffusion of drugs from skin patches Active - sodium potassium pump etc. Energy required From low concentration to high concentration EXAMPLE: neurons pumping sodium out of cell Endocytosis - entry of substances wrapped in membrane Receptor mediated endocytosis Protein in membrane recognizes substance to be engulfed Receptor proteins outside, clathrin coating on inside Binding of substance to receptor triggers infolding of membrane Membrane contacts self and fuses, forming a vesicle Vesicle processed inside cytoplasm, releasing contents Pinocytosis - pinching in to include a particle inside cell Phagocytosis - engulfing with cytoplasmic arms like an ameba EXAMPLES: macrophages of immune system eat bacteria Ameba feeding with pseudopodia exocytosis - reverse pinocytosis to secrete substances EXAMPLE: pancreas cells secrete digestive enzyme CELL ENERGETIC and more..
Passive - diffusion, osmosis No energy required From high concentration to low concentration EXAMPLE: diffusion of drugs from skin patches Active - sodium potassium pump etc. Energy required From low concentration to high concentration EXAMPLE: neurons pumping sodium out of cell Endocytosis - entry of substances wrapped in membrane Receptor mediated endocytosis Protein in membrane recognizes substance to be engulfed Receptor proteins outside, clathrin coating on inside Binding of substance to receptor triggers infolding of membrane Membrane contacts self and fuses, forming a vesicle Vesicle processed inside cytoplasm, releasing contents Pinocytosis - pinching in to include a particle inside cell Phagocytosis - engulfing with cytoplasmic arms like an ameba EXAMPLES: macrophages of immune system eat bacteria Ameba feeding with pseudopodia exocytosis - reverse pinocytosis to secrete substances EXAMPLE: pancreas cells secrete digestive enzyme
CELL ENERGETIC and more..
