Summary Topic 1: Cell Structure Notes

1. Cell structure
1. 1 The
:

Microscope in Ceu studies
calculate
magnifications of images and annual sizes
of specimens from drawings photomicrographs and
,

neuron
micrograph
.




Magnification = measured
length
actual size = measured
length
scale bar label
Magnification




| If / |
Unit Abbr .
Metric
Equivalent

Kilometer km 1,000m 103m


In
cent ,miner

.
can
I:m In
o.am , ozm


6m
-




micrometer µm 0.000001m 10
"
nanometer nm 0.000000001m 15 m




Define resolution and magnification and explain the differences between these terms , with
reference to hjwr
microscopy and electron microscopy

Magnification
Magnification is how
many
times
bigger
the
image of specimen
a observed is in
comparison to the actual size
of the
specimen
.




A
light microscope has two types of hens :




lens
→
eyepiece
↳ fixed at ✗ to
magnification
→ Objective lenses
↳ ✗ 4 ✗ 10 ✗ 40
, ,
] ✗these numbers to workout
total
magnification


Resolution
→ the to
distinguish two separate points
ability
The resolution
of light muioswpe is limited by the wavelength of light
a



↳ as light passes through the specimen it is diffracted
↳ the longer the wavelength the more diffraction

higher resolution and magnification
Electron have much
microscopes a


↳ much smaller wavelength than visible light
↳ can be much closer before diffracted beams
overlap

, 1.2 cells : as the basic units
of living organisms

Recognise organelles and other cell sometimes
found in eukaryotic cells and outline their structures and functions limited to :




cell Membrane
surface

exchange of
→ controls the materials between the internal an environment and the external environment


' '

→ partially permeable

→ formed from a
phospholipid bilayer of phospholipids
Cen Wan


structural
provide
→ to the an
support

→ made of cellulose in plants
bacterium
peptidoglycan in

→ narrow threads
of plasmodesmata convert the cytoplasm of neighbouring plant aus

Nucleus


→ cell
containing chromatin C complex of DNA and histone
provins)
a



↳
generic
mavenin
if the an




in an
→ present eukaryotic
cars




→ double membrane lnuueur envelope) separates it
from the agwpnasm .




→
Nalleur
pores allow mRNA and ribosomes out
of the nucleus

(Dna into the nucleus
enzymes polymerase)

Mitochondria

→ site
of aerobic respiration in
eukaryotic cues

→ matrix contains
enzymes
needed
for aerobic respiration
→ small curium
pieces of DNA found in matrix