Modular Monolith - a Practical Alternative to Microservices @ Devoxx UK 2024
AP BIO CH. 6.1-6.2
1. A Tour of the CellA Tour of the Cell
Ch. 6Ch. 6
Sections 6.1, 6.2Sections 6.1, 6.2
2. 3 Objectives in the Section3 Objectives in the Section
1.1. Microscope types – what kindMicroscope types – what kind
is best for different jobsis best for different jobs
2.2. Differences betweenDifferences between
prokaryotes and eukaryotesprokaryotes and eukaryotes
3.3. Why cells need to be smallWhy cells need to be small
4. Early MicroscopesEarly Microscopes
First microscopeFirst microscope
Jansen (Dutch) -Jansen (Dutch) -
15951595
Christopher Cock’sChristopher Cock’s
compound scopescompound scopes
(1665) used by(1665) used by RobertRobert
HookHook, Father of cell, Father of cell
biologybiology
7. Light MicroscopesLight Microscopes
Early scopes and modern scopes are lightEarly scopes and modern scopes are light
microscopes (LMs)microscopes (LMs)
Visible light passes through the specimenVisible light passes through the specimen
Image magnified by a series of lensesImage magnified by a series of lenses
8. MagnificationMagnification
The ratio of the projected image to the realThe ratio of the projected image to the real
size of the objectsize of the object
LMs can effectively magnify to ~ 1000xLMs can effectively magnify to ~ 1000x
9. Sizes of cellsSizes of cells
OneOne MICROMETERMICROMETER = 1/ 1,000,000 m= 1/ 1,000,000 m
OneOne NANOMETERNANOMETER = 1/1,000,000,000 m= 1/1,000,000,000 m
10. ResolutionResolution
A measure of how clear an image isA measure of how clear an image is
Determined by the minimum distance atDetermined by the minimum distance at
which 2 points can still be distinguished aswhich 2 points can still be distinguished as
2 separate points2 separate points
LMs have resolution of ~0.2 micrometersLMs have resolution of ~0.2 micrometers
at bestat best
Poor resolution
At what point can
you no longer
distinguish these
as separate lines?
11. ResolutionResolution
Human eye's resolving powerHuman eye's resolving power
Ability to distinguish betweenAbility to distinguish between
lines =lines = 1/10 mm1/10 mm
If closer, lines merge into 1 lineIf closer, lines merge into 1 line
12. Reverses image under field of viewReverses image under field of view
Light MicroscopeLight Microscope
13. Dark-Field MicroscopesDark-Field Microscopes
Light comes from the sideLight comes from the side,, makesmakes hugehuge
shadowsshadows and contrastsand contrasts
Good for LIVING CELLS
14. Phase-contrast MicroscopePhase-contrast Microscope
Waves of lightWaves of light
are set up,are set up,
bounced offbounced off
the specimenthe specimen
InterferenceInterference
causedcaused
byby
shape of cells isshape of cells is
plotted byplotted by
15. Electron MicroscopesElectron Microscopes
Developed in theDeveloped in the
1950s1950s
Instead of light, aInstead of light, a
beam of electrons isbeam of electrons is
focused on specimenfocused on specimen
16. Transmission Electron MicroscopeTransmission Electron Microscope
(T.E.M.)(T.E.M.)
Aims aAims a beam of electronsbeam of electrons instead ofinstead of
light waveslight waves THROUGHTHROUGH a section ofa section of
thethe specimenspecimen
200,000200,000 times bettertimes better
than the eyethan the eye
18. Preparation of specimenPreparation of specimen
Since cells are mostly water,Since cells are mostly water, need dye toneed dye to
show up,show up, block light raysblock light rays
Hydrophobic andHydrophobic and
hydrophillichydrophillic stainsstains
will dye organelleswill dye organelles
different densitiesdifferent densities
19. Scanning Electron MicroscopeScanning Electron Microscope
(S.E.M.)(S.E.M.)
Works like sonar, usingWorks like sonar, using electronselectrons toto
bounce off specimen's surfacebounce off specimen's surface
Limited resolutionLimited resolution butbut greatgreat 3-D3-D effecteffect!!
22. Preparation of specimensPreparation of specimens
First embedded in waxFirst embedded in wax
Sliced with aSliced with a
MICROTOMEMICROTOME
Specimens "shadowed"Specimens "shadowed"
with metalwith metal,,
for reflection, contrastfor reflection, contrast
ALL THESEALL THESE
PROCESSESPROCESSES
KILLKILL
CELLSCELLS
23. Pros & Cons of Microscope TypesPros & Cons of Microscope Types
LightLight ScanningScanning
ElectronElectron
TransmissionTransmission
ElectronElectron
ProsPros Can studyCan study
living cellsliving cells
Gives details onGives details on
surface of specimen;surface of specimen;
resolution 0.002resolution 0.002
micrometersmicrometers
Good for studyingGood for studying
internal cellinternal cell
structures; resolutionstructures; resolution
0.002 micrometers0.002 micrometers
ConsCons MagnificationMagnification
to only 1000x,to only 1000x,
resolutionresolution
only 0.2only 0.2
micrometermicrometer
Preparation of cellsPreparation of cells
kills them; limitedkills them; limited
resolutionresolution
Preparation of cellsPreparation of cells
kills them; need verykills them; need very
thin sections of cellthin sections of cell
parts (no depth)parts (no depth)
24. Quick ThinkQuick Think
With your neighbor, DISCUSS:With your neighbor, DISCUSS:
What type of microscope wouldWhat type of microscope would
you use to studyyou use to study
1.1. A living white blood cell?A living white blood cell?
2.2. The details of surface texture ofThe details of surface texture of
hair?hair?
3.3. The detailed structure of anThe detailed structure of an
organelle?organelle?
25. Separation of Organelles bySeparation of Organelles by CellCell
FractionationFractionation
Using a centrifuge to separate out successivelyUsing a centrifuge to separate out successively
smaller cell components for studysmaller cell components for study
Cell parts separated by size and densityCell parts separated by size and density
34. Answer:Answer:
Surface to volume ratioSurface to volume ratio needs to be largeneeds to be large
LOTS of materialsLOTS of materials need to pass through plasmaneed to pass through plasma
membranemembrane
DiffusionDiffusion only works well across very shortonly works well across very short
distancesdistances
NucleusNucleus can only handle so much info at oncecan only handle so much info at once
would “short out” if cells were much larger‑would “short out” if cells were much larger‑
35. Diffusion of substances across theDiffusion of substances across the
plasma membraneplasma membrane
Only so much stuff can pass across theOnly so much stuff can pass across the
membrane at any particular locationmembrane at any particular location
Larger cells cannot move enoughLarger cells cannot move enough
materials in and out to support the cellmaterials in and out to support the cell
37. Cell ShapeCell Shape
Tend to beTend to be sphericalspherical
because of cohesion &because of cohesion &
surface tensionsurface tension
Strongest structuralStrongest structural
shape, stableshape, stable (like bubbles(like bubbles
& balloons)& balloons)
If NOT spherical,If NOT spherical,
cell needscell needs internalinternal
and/orand/or
externalexternal
38. OrganellesOrganelles
Eukaryotic cells haveEukaryotic cells have
elaborateelaborate internalinternal
membranesmembranes that divide thethat divide the
interior of the cell intointerior of the cell into
compartmentscompartments
TheseThese membrane boundmembrane bound
compartments are calledcompartments are called
organellesorganelles
Each has a specific functionEach has a specific function
Each has a specific structureEach has a specific structure
41. The Cell Parts ProjectThe Cell Parts Project
NucleusNucleus
NucleolusNucleolus
RibosomesRibosomes
Smooth ERSmooth ER
Rough ERRough ER
GolgiGolgi
Vacuoles (food,Vacuoles (food,
contractile, central)contractile, central)
CentriolesCentrioles
MitochondriaMitochondria
ChloroplastChloroplast
CytoskeletonCytoskeleton
Cilia and flagellaCilia and flagella
Cell wallCell wall
LysosomesLysosomes
Plasma membranePlasma membrane
Do not
need
details of
p/s or c/r
42. Groups and TopicsGroups and Topics
You can choose your partner,You can choose your partner,
but topics will be assigned onbut topics will be assigned on
a first come, first serveda first come, first served
RANDOM basisRANDOM basis
Editor's Notes
http://www.olympusmicro.com/primer/anatomy/introduction.html Great site with lots of pics and scope info
Point out that prokaryotes ARE organized and complex; especially biochemically; accounts for their incredible diversity
Use box of tissues example here: Box itself has certain SA to volume ratio – tissues inside take up same volume, but much greater SA