Title: Cell Structure
URL Source: blob://pdf/889e7749-c2f4-470c-9ea1-f8f73ce04a0d
Markdown Content:
Cell Structure
AS Level
Chapter 1 Chapter Outline
Part 1: Microscopy
Magnification vs Resolution
Light Microscope vs Electron Microscope
Part 2: Micrometry: How do we measure cells?
Calibrating EPG using the Stage Micrometer (Practical 1)
Magnification
Part 3: Cell Structure and Function
Organelles
Animal vs Plant cells
Eukaryotes vs Prokaryotes
Viruses Updated on 12/7/21 by Beh SJ @behlogy MICROSCOPY LIGHT
MICROSCOPES
AND ELECTRON
MICROSCOPES
Updated on 12/7/21 by Beh SJ @behlogy Types of Microscopes
Electromagnetic radiation
(light / electrons)
Image of specimen
1. Light microscope
2. Electron microscope
a) Transmission Electron Microscopes (TEM)
b) Scanning Electron Microscopes (SEM)
> Updated on 12/7/21 by Beh SJ @behlogy
## Magnification and Resolution
1) Magnification
Number of times an image is enlarged,
compared with the actual size of the object
x sign placed in front of number
2) Resolution
Ability to distinguish between two points clearly as
separate
Units in nm
Increase in magnification increase in resolution
> Updated on 12/7/21 by Beh SJ @behlogy
## Magnification
Updated on 12/7/21 by Beh SJ @behlogy Resolution
High resolving power Low resolving power
Updated on 12/7/21 by Beh SJ @behlogy What determines resolution?
Range of electromagnetic radiations
of different wavelengths
Electromagnetic spectrum
Shorter wavelength used
Higher resolving power
Wavelength of visible light is longer than of an electron
Ability to distinguish between two points is lower
Max resolution is the
Shortest distance between 2 separate points
The max resolution = wavelength used
Shorter wavelength = higher max resolution = lower resolution
> Updated on 12/7/21 by Beh SJ @behlogy
## Resolution
For example:
Max resolution is the
Shortest distance between 2 separate points
The max resolution = wavelength used
Wavelength of visible light = 400 -700nm
Max resolution of a light microscope = 200nm
If closer/smaller than 200nm , points cannot be distinguished
as separate
Can a ribosome (smallest organelle) of 25nm be seen?
> Updated on 12/7/21 by Beh SJ @behlogy
## Light Microscope
Source of electromagnetic radiation: Visible light
- Wavelength = approx. 400 -700nm
- Lower energy and longer wavelength than electrons
- Focused using mirrors and glass lenses
Highest magnification: x1,500
Max resolution : 200nm (low)
Advantage: Live specimens can be
viewed, image can be coloured
Used for viewing structures that can be
measured in m Updated on 12/7/21 by Beh SJ @behlogy Electron Microscope
Source of electromagnetic radiation: Free electrons
- Wavelength = approx. 1 nm
- High energy, very short wavelength
- Must be in a vacuum environment so electron can
travel in straight lines
- Use electromagnetic lenses
Highest magnification: x250,000
Max resolution: 0.5 nm (high)
Disadvantage: Only dead material can
be examined in vacuum, images are black
and white
Used for viewing structures that can be
measured in nm Updated on 12/7/21 by Beh SJ @behlogy Updated on 12/7/21 by Beh SJ @behlogy Types of Electron Microscopes
a) Transmission Electron Microscopes (TEM)
b) Scanning Electron Microscopes (SEM)
> Updated on 12/7/21 by Beh SJ @behlogy
## Transmission Electron Microscopes
Beam of electrons
Pass through (transmit) specimen
before being viewed
2D appearance
Details inside cells
Internal structures
Membranes within internal
structures
> Updated on 12/7/21 by Beh SJ @behlogy
## Scanning Electron Microscopes
Lower resolution compared to TEM
Scan surfaces of specimens
3D appearance
> Updated on 12/7/21 by Beh SJ @behlogy
Q: List the differences between a light microscope and an electron
microscope. [4]
This is how you should ALWAYS present your answer to compare/contrast
between 2 things.
Features Light Microscope Electron Microscope
E.g. Highest
magnification of
microscope
Low er High er
4 marks = 4 points (1 mark is for table plus 1 just in case)
DO NOT tick or cross in the box.
Use comparative language.
Make your Feature as specific as possible.
(e.g. instead of magnification, write highest magnification of microscope)
> Updated on 12/7/21 by Beh SJ @behlogy
Features Light Microscope Electron Microscope
Type of radiation Light Electrons
Radiation travels through Air Vacuum
Wavelength of radiation Longer
400 -700 nm
Shorter
1 nm
Highest magnification of
microscope
Lower
x1500
Higher
x250,000
Max. resolution of
microscope
Lower
200 nm
Higher
0.5 nm
State of specimen Live Dead
Q: List the differences between a light microscope and an electron
microscope. [4]
A:
> Updated on 12/7/21 by Beh SJ @behlogy
# MICROMETRY HOW DO WE
MEASURE CELLS?
Updated on 12/7/21 by Beh SJ @behlogy Units
SI unit for length metre (m)
Suitable units for
Light microscope = micrometre (m)
Electron microscope = nanometre (nm)
Note:
Always measure image length in mm !!!
Present the actual diameter of structure in m
> Updated on 12/7/21 by Beh SJ @behlogy
Eyepiece graticule (EPG) is
on the eyepiece lens
Stage micrometer is
placed on the stage
## How do we measure cells?
> Updated on 12/7/21 by Beh SJ @behlogy
## How do we measure cells?
Two components needed:
The stage micrometer
Shows the true value of length
(Usually 10mm in length with 100 small divisions)
Appears bigger when magnification increases
The eyepiece graticule (EPG)
Shows 100 graticule units (100 EPG) which are in arbitrary units
Appears constant no matter the magnification
> Updated on 12/7/21 by Beh SJ @behlogy
(appears larger)
(appears constant)
Updated on 12/7/21 by Beh SJ @behlogy Two Steps:
1. Calibrate the EPG with the stage micrometer
1 EPG = __?___div = __?__ m
2. Use the EPG to measure cell/structure
1 cell = ___?__ EPG =__?__ m
## How do we measure cells?
> Updated on 12/7/21 by Beh SJ @behlogy
1. Calibrate the EPG with the stage micrometer
1 EPG = __?___div = __?__ m
15 EPG = 10 div = 0.1 mm
1 EPG = 0.1 mm/15
= 100 m/15
= 6.67 m
Eyepiece Graticule
Stage Micrometer
mm
> Updated on 12/7/21 by Beh SJ @behlogy
2. Use the EPG to measure cell/structure
1 cell = ___?__ EPG =__?__ m
Diameter of cell = 11 EPG
1 EPG = 6.67 m
Diameter of cell = 11 EPG * 6.67 m
= 73.37 m Updated on 12/7/21 by Beh SJ @behlogy Now you try!
Hint 1: the stage micrometer could be magnified under the microscope
Hint 2: 10 EPG is marked 1 here!
1. Calibrate the EPG with the stage micrometer
1 EPG = __?___div = __?__ m
Q: Given that 100 divisions of the stage micrometer measures 1mm,
calibrate the EPG.
> Updated on 12/7/21 by Beh SJ @behlogy
A:
100div = 1mm
1div = 0.01mm
= 10m
50 EPG = 10div
50 EPG = 10 * 10m
= 100 m
1 EPG = 100 m / 50
= 2m
Q: Given that 100 divisions of the stage micrometer measures 1mm,
calibrate the EPG.
> Updated on 12/7/21 by Beh SJ @behlogy
Number of times an image is enlarged ,
compared with the actual size of the object
Formula:
=
Remember to convert all measurements to the same units!
Pro tip:
## Magnification
1. Convert
2. Substitute
3. Calculate
> Updated on 12/7/21 by Beh SJ @behlogy
## Exercise
Q: On an electromicrograph , a mitochondrion measures 36mm in
length.
If the magnification of the micrograph is x30,000,
what are the actual length of this organelle in m?
M = x30,000
I = 36mm = 36*1000 m = 36000 m
A = I / M
= 36000 m / 30 000
= 1.20 m
1. Convert
2. Substitute
3. Calculate
> Updated on 12/7/21 by Beh SJ @behlogy
Q: Given that the magnification of this electron micrograph is
x20,000, calculate the actual length of this mitochondria.
## Exercise
60mm
> Updated on 12/7/21 by Beh SJ @behlogy
Q: Given that the magnification of this electron micrograph is
x200,000, calculate the actual length of this mitochondria.
M = x20,000
I = 60mm = 60 * 1000 m
= 60,000 m
A = I / M
= 60,000 m / 20000
= 3 m
## Exercise
1. Convert
2. Substitute
3. Calculate
> Updated on 12/7/21 by Beh SJ @behlogy
Q: This is a micrograph taken by an electron microscope of the
egg of an Aedes mosquito.
What is the magnification of this image?
## Exercise
You need to physically measure the scale bar!
A = 200nm
I (measured) = 13mm = (13*1000*1000)nm
= 13000000nm
M = I / A
= 13000000 / 200
= x65,000
Magnification should always have a x
in front and expressed in whole numbers
> Updated on 12/7/21 by Beh SJ @behlogy
# CELL STRUCTURE
# AND FUNCTION
Updated on 12/7/21 by Beh SJ @behlogy Cell Structure and Function
Organelles
Functionally and structurally distinct part of a cell
Surrounded by membranes
For compartmentalization
So that reactions do not interfere with each other
Each has separate, specific function
Ultrastructure of cells
Not necessarily surrounded by membranes
Detailed structures of a cell
Only can be seen under an electron microscope
> Updated on 12/7/21 by Beh SJ @behlogy
Two types of cells: Prokaryotes vs Eukaryotes
on the Tree of Life
Lets talk about this
type of cells first!
> Updated on 12/7/21 by Beh SJ @behlogy
## List of Eukaryotic Cell Structures
Plant + Animal Cells included!
1. Cell surface membrane
2. Nucleus, nuclear envelope and
nucleolus
3. Ribosomes
4. RER
5. SER
6. Golgi body
7. Lysosomes
8. Mitochondria
9. Chloroplast
10. Cell wall
11. Plasmodesmata
12. Vacuole and tonoplast
13. Centrioles
14. Microtubules
15. Cilia
16. Microvilli
1) Name it 2) Recognise it 3) Know its function
You need to:
> Updated on 12/7/21 by Beh SJ @behlogy
Electromicrograph of a cell
You should learn to identify the main organelles visible here!
> Updated on 12/7/21 by Beh SJ @behlogy
## 1. Cell Surface Membrane
Plasma membrane
~7 nm thick
Seen as three layers at x100,000
Trilaminar appearance
Partially permeable
Made of phospholipid bilayer
Function :
Controls movement of substances into
and out of the cell
> Updated on 12/7/21 by Beh SJ @behlogy
Largest organelle!
Has double membranes
General Function :
Contains genetic information
for the synthesis of proteins
Site of transcription of genes and
production of mRNA
DNA is protected from
degradation by enzymes
## 2. Nucleus
> Updated on 12/7/21 by Beh SJ @behlogy
Components:
1. Nuclear envelope
Attached to ER
2 membranes
Have nuclear pores
Function : Controls movement of
substances between nucleus and
cytoplasm
2. Nucleolus
Densest region
Function : Site of ribosomal RNA (rRNA) synthesis
Site of ribosome assembly
3. Chromatin = DNA and its associated proteins
## 2. Nucleus
> Updated on 12/7/21 by Beh SJ @behlogy
## 3. Ribosomes
Smallest organelle!
Not bound by a membrane
Made of rRNA , that is synthesized in
nucleolus + some protein
Has 2 subunits
Function :
Site of protein synthesis
> Updated on 12/7/21 by Beh SJ @behlogy
## 3. Ribosomes
Two types:
1. 80S ribosomes are
25nm (rmb this!)
Larger
Found in cytoplasm and RER
of all eukaryotes
2. 70S ribosomes are
18nm
Smaller
Found in mitochondria and
chloroplasts of eukaryotes
Found in all prokaryotes Updated on 12/7/21 by Beh SJ @behlogy 4. Rough Endoplasmic Reticulum
Extensive, connected system of membranes
Made of cisternae (flattened membrane sacs)
Continuous with the nuclear envelope
Running through the cytoplasm
80S ribosomes are attached
Functions :
Site of protein synthesis ,
protein modification
e.g. protein folding
e.g. glycosylation = addition of carbohydrate chains to protein
protein transport to Golgi
> Updated on 12/7/21 by Beh SJ @behlogy
## 5. Smooth Endoplasmic Reticulum
ER without ribosomes
Function:
Site of lipid and steroid synthesis
e.g. cholesterol, steroid hormones
> Updated on 12/7/21 by Beh SJ @behlogy
## 6. Golgi body
Golgi apparatus / complex
Made of cisternae
Have layered appearance
No connection between members
Not continuous with nuclear envelope
Swellings at end of sacs for vesicle formation
Constantly being formed and broken down
Being formed by : Transport vesicles from RER on cis face
Broken down to form : Secretory vesicles and lysosomes on trans face
> Updated on 12/7/21 by Beh SJ @behlogy
Functions :
Modification of proteins and lipid
E.g. glycosylation
phosphorylation = addition of phosphate gp to proteins
cutting / folding proteins
Packaging molecules into vesicles for transport
Formation of secretory vesicles for release of protein out of
the cell
Formation of lysosomes
## 6. Golgi body
> Updated on 12/7/21 by Beh SJ @behlogy
## Production and Secretion of Proteins
Updated on 12/7/21 by Beh SJ @behlogy Production and Secretion of Proteins
Updated on 12/7/21 by Beh SJ @behlogy Production and Secretion of Proteins
List the cell structures involved in sequence:
Steps:
1. Synthesis of protein at ribosome / RER
2. Transport vesicle buds off RER and fuses with Golgi body
3. Modification of protein at Golgi body
4. Separation of a secretory vesicle from the Golgi body
5. Fusion of the vesicle with the cell surface membrane
6. Contents released / secretion of protein by exocytosis
Process also works to embed a protein at the cell membrane.
OUT
> Updated on 12/7/21 by Beh SJ @behlogy
## Exercise
[CIE, June 2013, P13, Q5]
When mucus is secreted from a goblet cell in the trachea, these
events take place.
1. addition of carbohydrate to protein
2. fusion of the vesicle with the plasma membrane
3. secretion of a glycoprotein
4. separation of a vesicle from the Golgi apparatus
What is the sequence in which these events take place?
A: 1 4 2 3
> Updated on 12/7/21 by Beh SJ @behlogy
Very, very small
Spherical, small sacs
Function:
Contains hydrolytic enzymes / lysozymes
Breakdown unwanted structures via hydrolysis in an acidic enviro
Worn out organelles or dead cells
In WBC, lysozymes digest bacteria
## 7. Lysosomes
> Updated on 12/7/21 by Beh SJ @behlogy
## 8. Mitochondria
Relatively large organelle
Has double membranes
Cristae = folded inner membrane
Matrix = interior solution
Contain 70S ribosomes and
small circular DNA
Divide by binary fission
Have prokaryotic origin
> Updated on 12/7/21 by Beh SJ @behlogy
## 8. Mitochondria
Functions :
Site of aerobic respiration
synthesize ATP/produce energy
in the form of ATP
release energy
Please DO NOT write
Mitochondria produces energy
Mitochondria is the powerhouse of the cell
-.-
> Updated on 12/7/21 by Beh SJ @behlogy
Label the following electron micrograph of an animal cell.
## 8. Mitochondria
> Updated on 12/7/21 by Beh SJ @behlogy
## 8. Mitochondria Q: Why are these mitochondria
shaped so differently?
A:
One is a longitudinal cross section and
the other is a transverse cross section!
Also shape may sometimes vary.
> Updated on 12/7/21 by Beh SJ @behlogy
## 9. Chloroplasts
Relatively large organelle
Oval shaped
Two membranes
Contain chlorophyll
Thylakoid = flattened
membrane sacs
Grana = thylakoid stacks
Stroma = interior solution
Contains 70S ribosomes, small circular DNA and starch grains
Divide by binary fission
Have prokaryotic origin
> Updated on 12/7/21 by Beh SJ @behlogy
## 9. Chloroplasts
Updated on 12/7/21 by Beh SJ @behlogy 9. Chloroplasts
Updated on 12/7/21 by Beh SJ @behlogy 9. Chloroplast
Function:
Site of photosynthesis
Two main processes in photosynthesis:
1. Light -dependent reaction (aka light reaction)
Light energy absorbed and water is used to synthesise ATP
2. Light -independent reaction (aka dark reaction)
ATP used to convert CO 2 into glucose
> Updated on 12/7/21 by Beh SJ @behlogy
## 10. Cell Wall
Thick, rigid layer
Made of cellulose
Permeable
Bcs there are spaces / gaps
between fibres
Functions :
Provide structural support
Prevent bursting
Limit cell size
> Updated on 12/7/21 by Beh SJ @behlogy
## 11. Plasmodesmata
Strands of cytoplasm passing
through channels
Functions :
Allows substances to pass
From cell to cell
Without passing through cell walls
E.g. water, sucrose, amino acids, minerals ions, ATP
Allows more rapid transport of substances
> Updated on 12/7/21 by Beh SJ @behlogy
## 12. Vacuoles and
## Tonoplast
Commonly found in plant cells
Large, permanent, central
Surrounded by a partially permeable
membrane called tonoplast
Functions :
Store of cell sap (contains water, ions,
minerals, salts, pigments, sugars)
Stores waste products
Pushes chloroplasts to edge of cell
Gives turgidity to the cell
> Updated on 12/7/21 by Beh SJ @behlogy
## 12. Vacuoles and
## Tonoplast
Updated on 12/7/21 by Beh SJ @behlogy 13. Centrioles and Centrosomes
Centrioles are cylindrical
Made of 9 groups of 3 microtubules
Not found in plant cells
Functions of Centrioles :
Involved in cell division
Replicates before each cell division and moves to opposite poles
Centrioles are found in pairs at right angles (90 o) from each other
Forms centrosome
Modified centrioles are also found elsewhere e.g. in flagella / cilia
Acts as a Microtubule Organising Centre (MTOC)
Organises / assembles microtubules
> Updated on 12/7/21 by Beh SJ @behlogy
## 13. Centrioles and Centrosomes
Function of Centrosomes :
It is a MTOC
Organises / assembles microtubules
For the formation of spindle fibres
At opposite poles
During cell division /mitosis
Aid contraction of spindle
fibres to separate sister
chromatids
> Updated on 12/7/21 by Beh SJ @behlogy
## 14. Microtubules
Very small (~25nm)
Made from tubulin
Form dimers
Dimers polymerise to form long
protofilaments
13 protofilaments = 1 microtubule
Long, rigid, hollow tubes
Formed and broken down at
Microtubule Organising Centres
(MTOCs)
E.g. centrosomes, centrioles near
flagella/cilia Updated on 12/7/21 by Beh SJ @behlogy 14. Microtubules
Updated on 12/7/21 by Beh SJ @behlogy 14. Microtubules
Functions :
Make up the cytoskeleton
(together with actin filaments)
Provides mechanical support
Acts as an intracellular transport system
for movement of vesicles or other components
> https://www.youtube.com/watch?v=y -uuk4Pr2i8
Beating of flagella
Makes up spindle fibres and centrioles
used in cell division
> Updated on 12/7/21 by Beh SJ @behlogy
## 15. Cilia
Only found in eukaryotes
Smaller in diameter than microvilli
Also not to be confused with flagella (mostly
found in prokaryotes)
Motile / moves rhythmically
Complicated structure made of
microtubules
Function :
For movement / locomotion
E.g. ciliated epithelial cells in lungs,
Paramecium (eukaryotic microbe)
> Updated on 12/7/21 by Beh SJ @behlogy
## 16. Microvilli
Only found in animal cells
Found on epithelial cells in the
intestines and kidneys
Finger -like extensions of the cell
surface membrane
Functions :
Increase surface area
of the cell membrane for:
Absorption
Secretion of enzymes
Digestion at the cell surface
Excretion of waste substances
> Updated on 12/7/21 by Beh SJ @behlogy
## Centrifugation
Q: What happens if we rupture
cells and spin them at high
speed?
A: The larger structures will
sediment first.
> Updated on 12/7/21 by Beh SJ @behlogy
Compare and contrast the structure of
an animal cell and a plant cell. [4]
Feature Animal cell Plant cell
Similarities:
Differences:
> Updated on 12/7/21 by Beh SJ @behlogy
## Similarities between
## Animal and Plant Cells
Plasma membrane
Nucleus
Nucleolus
Cytoplasm
Other organelles
(eg : mitochondria, Golgi apparatus, ribosomes, lysosomes)
> Updated on 12/7/21 by Beh SJ @behlogy
Differences between
Animal and Plant Cells
Feature Animal Cells Plant Cells
Shape of cell No fixed shape Fixed shape
Presence of Cell
Walls Absent Present
Presence of
plasmodesmata Absent Present
Presence of vacuoles Absent, if present,
small, temporary
Present, large and
permanent
Presence of
chloroplasts Absent Present
Presence of
centrosomes Present Absent
> Updated on 12/7/21 by Beh SJ @behlogy
Two types of cells: Prokaryotes vs Eukaryotes
on the Tree of Life
Now lets talk about
this type of cells!
> Updated on 12/7/21 by Beh SJ @behlogy
## Prokaryotes vs Eukaryotes
Pro karyotes
pro = before
karyon = nucleus
Includes all bacteria
and archaea
Eu karyotes
eu = true
karyon = nucleus
Includes plants,
animals, fungi and
other microbes
> Updated on 12/7/21 by Beh SJ @behlogy
## Prokaryotic Cells: A typical bacterium
Unicellular
Relatively smaller ( 1-5m )
Simpler in structure
Divides by binary fission
What all bacteria do not have:
No membrane -bound organelles
No nucleus
DNA lies free in cytoplasm
in the nucleoid region
> Updated on 12/7/21 by Beh SJ @behlogy
## Prokaryotic Cells: A typical bacterium
What all bacteria have:
Plasma membrane
Cytoplasm
Peptidoglycan cell wall
m ade of chains crossed
linked by amino acids
70S ribosomes
Circular DNA
DNA is naked
not associated with
proteins
> Updated on 12/7/21 by Beh SJ @behlogy
What is only present in some bacteria:
1) Plasmids
Small, circular DNA
Codes for non -essential proteins
Several may be present
2) Pili
Sexual reproduction
For attachment to other
cells/surfaces
## Prokaryotic Cells: A typical bacterium
> Updated on 12/7/21 by Beh SJ @behlogy
## Prokaryotic Cells: A typical bacterium
3) Flagellum
Locomotion
4) Capsule
Outer coat, additional protection
Attach to surfaces
5) Infoldings of plasma membrane
(mesosomes)
For photosynthesis / nitrogen fixation
> Updated on 12/7/21 by Beh SJ @behlogy
## Prokaryotes,
## Mitochondria and Chloroplast
They have a lot in common!
Both have:
Similar size
Small, circular DNA
70S ribosomes
Division by binary fission
But why???
> Updated on 12/7/21 by Beh SJ @behlogy
A: The Endosymbiotic Theory
https://www.youtube.com/watch?v=FGnS -Xk0ZqU
P/S: This is not in syllabus!
## Prokaryotes,
## Mitochondria and Chloroplast
Updated on 12/7/21 by Beh SJ @behlogy Compare and contrast the structure of a
eukaryotic cell and prokaryotic cell. [4]
Feature Prokaryotic cell Eukaryotic cell
Similarities:
Differences:
> Updated on 12/7/21 by Beh SJ @behlogy
## Eukaryotic Cells
Larger (~10 -100m in diameter)
Has membrane -bound organelles
Has nucleus
DNA is linear
DNA associated with proteins
Larger 80S ribosomes
Cellulose cell walls (plants)
Chitin cell walls (fungi)
> Updated on 12/7/21 by Beh SJ @behlogy
## Viruses
Non -cellular structure
~50 times smaller than bacteria (20 -300nm)
Much simpler
No plasma membrane, cytoplasm, ribosomes
Only:
1. Nucleic acid core = DNA or RNA
2. Capsid = protein coat
- Protective coat
- May have one or two coats
3. Some viruses also have an
outer envelope made of phospholipids
4. Some proteins may be present
- e.g. haemagglutinin, neuraminidase
> Updated on 12/7/21 by Beh SJ @behlogy
## Viruses
All parasitic
Can only reproduce by infecting living cells
Uses protein synthesising machinery of
host cell to replicate
Are they considered living?
> Updated on 12/7/21 by Beh SJ @behlogy
## List of Eukaryotic Cell Structures
Plant + Animal Cells included!
1. Cell surface membrane
2. Nucleus, nuclear envelope and
nucleolus
3. Ribosomes
4. RER
5. SER
6. Golgi body
7. Lysosomes
8. Mitochondria
9. Chloroplast
10. Cell wall
11. Plasmodesmata
12. Vacuole and tonoplast
13. Centrioles
14. Microtubules
15. Cilia
16. Microvilli
1) Name it 2) Recognise it 3) Know its function
You need to:
> Updated on 12/7/21 by Beh SJ @behlogy
## Important Terms to Remember
Pay attention to those bold, highlighted red text and whats
emphasised in class!
In addition to the list of 16 eukaryotic cell structures to remember:
Bacteria (Prokaryote)
(No membrane -bound organelles)
1. Nucleoid region
2. Peptidoglycan cell wall
3. Circular DNA
4. 70S ribosome
5. Plasmids
Virus
1. DNA / RNA
2. Capsid (protein coat)
3. Envelope
> Updated on 12/7/21 by Beh SJ @behlogy
## Chapter Outline
Part 1: Microscopy
Magnification vs Resolution
Light Microscope vs Electron Microscope
Part 2: Micrometry: How do we measure cells?
Calibrating EPG using the Stage Micrometer (Practical 1)
Magnification
Part 3: Cell Structure and Function
Organelles
Animal vs Plant cells
Eukaryotes vs Prokaryotes
Viruses Updated on 12/7/21 by Beh SJ @behlogy Videos
Seeing the Invisible: van Leeuwenhoek's first glimpses of the microbial world:
https://www.youtube.com/watch?v=ePnbkNVdPio
Principles of electron microscopes
https://www.youtube.com/watch?v=ljTEG -B-kGc
Organelles involved in protein synthesis
https://www.youtube.com/watch?v=26y1PCkWiIc
Inner Life of the Cell (3:00 onwards its hard to understand what he is saying, but the 3D animations
gives you a clue on how the cytoskeleton works and how protein production relies on it too!)
https://www.youtube.com/watch?v=FzcTgrxMzZk
Inside the living cell
https://www.youtube.com/watch?v=d4TJ4NY1IA0
OK warning! All videos are for reference and
entertainment only and ALWAYS contain too
much/ too little/irrelevant info.