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Fractionation
Take whole cell and divide it
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Microscopy has two conponets
- 1. Resolution
- 2. Magnification
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Resolution
Minimum distance two points can be apart and still be distinguished as two separate pts. The smaller the better.
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Magnification
Ratio between what we see and what were looking at. Image vs. What were looking at/ higher magnification the more we see.
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Light microscope
Compund microscopes (multiple lenses), utilizes light for illumination.
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What is the resolution of light
200nm - limited by wavelengths
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Wet mount
Drop containing microorganism placed on slides.
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Smear
Sample containing microbes/ media onto the slides. Heat fixed (kills bacteria)
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Staining
Stains bind to certain cellular structures and give it color.
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There a two type of Electron Microscopes
- 1. transmission electron microscopy (TEM)
- - heavy metal
- - electon (some) scattered, w/o pass through to form an image.
- 2. scanning
- - heavy metal coated
- -scan to make 3D
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Why are cells small
- The more surface area the better. When size increase volume increases rapidly.
- s=4(pie)r^2
- ration s/v= 4(p)^2/(4/3)(p)r^3=3/r
- V=4/3(p)r^2
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What do cells have in common.
- Genetic material
- - single circular molecules in prokaryotes
- -double helix (nucleus in eukaryotes)
- Cytoplasm- fills cell interior
- plasma membrane- encloses the cell
- ribosomes- carry out protein synthesis
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-Simple cell structures- No nucleus
- lack a membrane enclosed nucleus
- 2 groups (bacteria and Archea)
-Archea (related to eukaryotes) and bacteria are grouped together
Prokaryotic Cell
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Shapes of Bacteria
- Bacillus (rod)
- Coccus (sphere)
- Spirillum (spiral)
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Phylogenetic Tree of life 3 domains
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Simples organism of the bacteria cell
- Cytoplasm contains DNA, ribosomes have granules, vesticles & os surronded by plasma membrane.
- - DNA is circular
- - no compartments
- - Cell Walls
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What do Prokaryotic DNA look like?
- -Circular
- - double helix
- -plasmid of DNA (small circular stretches of DNA)
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What strucutures are located on the outside of the Prokaryotic DNA?
- -Cell wall- support and protections
- - Glycocalyx (capsule)- trap h20, protection
- - appedndages- pili (attatchment), flagella (locomotion)
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Prokaryotic Cell move how?
Flagella- thread like structure protruding from the cell
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What is Flagella?
Complex is a nano-scale motor which allow bacteria to move.
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Chemotaxis
- - Movement towards attraction or away from repellants
- - some bacteria exhibit phototaxis
- (movement towards and away lights)
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Cell wall (prokaryote)
- 1. maintain cell shape
- 2. prevents cell from bursting
- - Bacteria have walls made of peptidoglycon (murein)- polymermade of repeating sugar units linked to short peptides.
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Gram Positive bacteria
Thick Layer of peptodglycon
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Gram Negative
- Thinner layer of peptidoglycon but more complex cell wall
- _ also have lipopoly saccharid layer
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Gram Staining
- - Insoluble crystal violent complex is formed inside cells.
- Alchol dehdrates pores in thick gram positive wall
- alchols penetrates lipid rich layers of gram negative cells extract dye.
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PG of Grahm positive cell can be digestive by?
- Enzymes lysozome can degrade cell wall in gram positive cell.
- After cell wall is degraded, h20 enters the cell- cell burst (lysis).
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Peptidoglycon
- - only in bacteria
- - not in Archea and Eukaryotes
- - diffrent versions
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Eukaryotic cell
- Dna inside nuclues
- compartmentalized
- organelles
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Organelles
Sub cellular structure or membrane bonded compartment w/ its own function/ structure.
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Proteome
- Determines characteris and function and structure of a cell
- - diffrent from cancerous cells
-
Genome
All genes (DNA sequence) of an organism
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Proteome is made of what?
Set of all proteins
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Cytosol
Region of Eurkayotic cell outside the cell oraganelles inside plasma membrane and has many metabolic activities.
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cytoplasm
- everything in plasma membrane
- - cytosol-endomembrane system and the semiautonomous organelle
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Catabolism
Breakdown of molecules
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Anabolism
small - big of synthesis of cellular molecules and marcomolecules
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Nucleus
Repository for genetic material
-
Nucleolus
- Region of ribosome RNA synthesis
- - nuclear membrane is made of 2 phospholipids bilayers
- - nuclear pores play a role of importing and exporting protein/RNA.
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Chromosome
- -Linear stretch of DNA (divided)
- - exist of strands of chromatin except cell division
- - associated w/ histones
- - complex organiztion DNA packed
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Endomembrane system
- - network of membranes: nuclear, ER, GA, lysosomes and vacuoles, plasma membrane.
- - Connected to eachother or pass material by vesicles
- -compartmentalized cells, channeling pasage of molecules through cells interior.
- - rough and smooth ER
-
Rough ER
- Studded with ribosomes
- site of protein synthesis and scretion
- Glycosylation of some proteins
-
Smooth ER
- Lack ribosomes
- site of detoxication
- synthesis and modification of lipids (hormones/chromosomes)
-
Ribosomes
- Rna complexes composed of two subunits that join and attach to messenger RNA
- site of protein synthesis
- assembled in nuclioli protein and rna catalytic roles
- diffrent in prokaryotes and eukaryotes
-
Golgi Apparatus
- Site of modification, sorting and secretion of lipids and proteins
- stack of flattened membrande- bound compartments
- not continious with ER
- vesicles transport material between stacks
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Lysosomes
- Recycle worn out organelles through endocytosis
- contain acid hydrolases that perform hydrolysis
- diffrent types of acid hydrolases to break down proteins, carbs and nucleic acid and lipids
-
Hydrolases
Enzymes which hydrolize molecules
-
vacuoles
- Function varies
- diffrent with cell types and environmental condition
-
Central Vacuoles
Storage and support in plants
-
contractile vacuoles
in protist for expelling excess water
-
phagocytic vacuoles
protists and white blood cells for degradtion
-
Plasma membrane
- Boundary between cell and extracellular environment
- membrane transport in an d out fo cell
- selectively permeable
- cells signaling using receptors
- cell adhension
-
Cytoskelton
- Network of 3 ortein filaments
- 1. microtubules
- 2. intermediate filaments
- 3. actin filaments
-
Microtubules
- Dynamic instability
- Centrosome/ microtubule- organiztion center in animal
-
Intermediate Filaments
Stable than microtublues and actin fillament
-
Actin Filament
Microfilaments
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Motor Proteins
ATP energy source for movement
-
Three domains for motor protein
Head Hinge and Tail
-
Diffrent Movements for Motor Proteins
- 1. Move cargo
- 2. remain in place, filament moves
- 3. attempting to "walk" exerts a force that causes the filament to bend.
-
-
Cilia and Flagella
- same internal structure
- microtubules, dyen and axoneme
-
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Mitochondria
- Exterior and interior membrane
- inner membrane and inter membrane space
- oxidation furing metabolism
- DNA but cannot reproduce independtinly
- ATP Synthesis role
-
Chloroplast
- Photosynthesis
- found in all species of plants and algae
- two membrane around them
- thrid membran (thylakoid) forms flattened tubules that stack to form a granum.
-
Mitochondria And Chloroplast have 2 traits similar to bacteria
- 1. Have own DNA
- Circle double helix
- own ribosomes (bacteria like)
- similar to bacterial chromosomes
- 2. reproduce bia binary fission
-
Endosymbiosis
Originated by engfulfed prokaryotes provided hosts with advantages associated with specilized metabolic activites.
-
Mitochondria and chloroplasts are derived from what ancient symbiotic relationships are?
- Endosymbiosis- smaller species lies inside a larger species
- genes of mitochondria and cholorplasts similar to bacteria genes
- lost most of their genes through transfer to nucleus
-
evidence of endosymbiotic theory
- 1. ribosomes of prokaryotic origin
- 2. dna is circular
- symbiosis between protozoa and prokaryotes
-
Peroxisomes
- found in eukaryotic cells
- catalyze certain chemical reactions- break down molecules by removing hydrogen or adding oxygen
- reaction by-product is hydrogen peroxide (H2O2)
- catalase breaks down H2O2 w/o forming dangerous free radicals
- prevent harm
-
Biological membrane
- Phospholipid bilayer- amphipathic (hydrophilic head, hydrophobic tails)
- Protein embedded in membrane
- (intergral and peripheal)
-
Memabranes are selectively permeable to ensure?
- Essential molecules enter
- metabolic intermediates remain
- wast producs exit
-
Phospholipid bilayer is a barrier by what?
- Hydrophobic interior serves as a barrier to hydrophilic molecules
- solutes vary in their rates of penetration
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Transmembrane gradient
Concentration of a solute is higher on one side of a membrane than the other
-
Ion electrochemical gradient
Electral and chemical gradient
-
What are three Passive transports and does it require energy?
- No energy
- Diffusion
- passive diffusion
- Faciliated diffusion
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Diffusion
net movement of substances from regions of high concentration to regions of low concentration
-
Passive diffusion
Solute through a membrane w/o transport protein
-
faciliated diffusion
diffusion of a solute through a membrane with the aid of transport protein
-
Two types of diffusion across the membrane?
-
Isotonic
- Equal water and solute concentration
- (h2
-
Hypertonic
Solute concentration is higher (h20 content low on one side)
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Hypotonic
Solute concentration is lower (h20 con. higher on one side)
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Osmosis
- water diffuses through the membrane from an high h20 to low h20.
- Ifs solute cant move, water movement makes cell shrin/swell as water leaves/enter the cell.
- osmotic pressure
-
Animal cells must balance what solute to maintain size and shape?
- Intracellular
- extracellular
-
What prevent major changes to plants cell size?
Cell wall
-
-
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What enables biological membrane to be selectively permeable?
transport proteins
-
Channels
Form an open passesageway for direct diffusion of Ion/molecules towards membranes.
-
ion Channels
- Import transmitting nerve cell signals
- neurotoxins block ion channel (snake,Scorpion)
- Lidocanie and Nococaine are Ion channel blockers
- drug targets
-
Transporter
- Conformation change transports solute
- uptake of organic molecules (sugar amino acids)
- Key role is to export
-
Uniporter
Single Molecule or ion
-
Symporter/Contransporter
2 or more ions or molecules transported in same direction
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Antiporter
2 or more ions or molecules transported in opposite directions
-
What are the 3 transporter types?
- Uniporter
- Anitporter
- Symporter/contronsporter
-
Active transport
- against the gradient
- requires energy
-
Primary active transport
Directly use energty to transport solute
-
secondary active transport
Use energy stored in gradient of a diffrent molecules
-
pump
Couples and changes to energy source
-
Atp driven pump
- htp hydrolosis
- uniporter,symportermantiporters
- active transports
-
Exocytosis
Material inside the cell, packed into vesicles and is excreted into extracellular medium
-
Endocytosis
Plamsa membrane invaginates or folds in to form a vesicle that brings substances into the cell
-
Receptor
Mediated Endocytosis
-
Pinocytosis
Cell drinking
-
Phagocytosis
Engulfs a particle
-
sodium and potassium ATPase
- Actively transport Na and K against their gradients by using the energy from ATP hydrolysis
- 3 NA exported for 2 K imported into cell
- -anitporter
- electrogenic pump- export 1 net positive charge.
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