Chapter 1- Cells , Microscopy Flashcards
what is the function of Centrioles
- centrioles are involved in the movement of chromosomes in the cell division
what is the function of microtubules
*hint 2
They support the cells shape and help it move.
They help organise and move organelles in the cell.
8Os Ribosomes are found where in a cell
cytoplasm
ER
70s Ribosomes are found where
Chloroplasts
Mitochondria
what is the function of Ribosomes
They provide site for Protein synthesis
Function of ER
-They help transporting of protein
-synthesis of polypeptides
-creates transport vesicles
Function of smooth ER
Involved in synthesis of hormones and lipids
Function of Golgi body
They modify the proteins for functionality
Steps taken through the Golgi for modification of proteins
*hint 5 steps
1- Vesicles are released containing protein from the rough ER
2-These vesicles attach onto the Golgi body and proteins here are modified
3-After modification the vesicles now carry the new modified protein off from the Golgi
4-Some escape to the cell membrane where they are taken out of the cell (exostosis)
5-Some vesicles are Lysosome containing Hydrolase enzyme
Function of Granum in the chloroplasts
They contain the chlorophyll molecules that help with absorption of light energy then transfer it to other molecules to generate ATP.
state the Mitochondrion’s funtion
they act as the site of aerobic respiration whereby glucose is broken down which results into release of energy to create ATP
what is the function of Cristae in the mitochondria
they increase the surface area for enzymes
Function of Lysosomes
They breakdown of unnecessary/ old organelles
which cells use Lysosomes
White blood cells, phagocytes to digest engulfed pathogens
what substances are present in the cell wall
Primary layer- Cellulose
Secondary layer-Lignin
Middle lamella- Pectin
What is the envelope of a virus made up from.
Phospholipids
Mention 3 differences between Prokaryotes and eukaryotes
-PRO only has 70s ribosomes present while EUK has 80s
-PRO has no membrane bound organelles EUK does
- PRO do not have centrioles EUK does
- PRO are smaller (1-10um) while EUK is larger (5-100um)
-PRO do not have a nucleus while EUK have a nucleus
Centrioles are present in Plant cells, True or False?
FALSE
1 centimeter to micrometers
1cm= 10000
1 mm to nanometer
1mm = 1,000,000 nanometers
equation of magnification
Image divided by Actual size
I / A M
How does a light microscope view the specimen
Through illumination of light
The Max. magnification of light microscopes are
x1500
what is magnification
The number of times larger an image is compared to its actual size.
what type of stains are seen in light and electron microscopes
light- coloured dyes
electron-heavy metals
what is resolution
the ability to distinguish between 2 objects that are close together
max resolution in light and electron
light-200nm cannot see ribosomes
electron-0.5nm
suggest 3 organelles that are bounded by a single membrane
-lysosome
-vacuole
-ER
-Golgi body
Suggest 3 organelles that are bound by no membrane
-ribosomes
-centrioles
-microvilli
-flagella
-cillia
-cytoskeleton
suggest 3 organelles that are bounded by double membrane
-mitochondria
-nucleus
-chloroplast
what does the structure of viruses contain
-RNA/DNA that is self replicating
-protein coat/capsid
-some have a slime capsule
2 categories of electron microscopes
1) transmission electron microscopes- electrons are PASSED through the specimen
2)Scanning electron microscopes- This DETECTS electrons that have been reflected from the surface of the specimen.
why is the TEM good?
This is because it can allow thin surfaces to be observed and thus can see inside cells
why is the SEM good?
The surface structures can be seen
A 3-D image can be gotten which can interpret the structures better
differences between the SEM and TEM
- The SEM cannot achieve the same resolution like the TEM (higher)
- 3D surface sample for SEM while 2D internal structure
- SEM have a lower magnification than TEM
- SEM can use larger and thicker samples while TEM is limited to thin and transparent ones
why can only dead molecules be used for an electron microscope
this is due to water boiling at room temperatures when in a vacuum so all specimens must be dehydrated.
evaluate the use of a light microscope
+ Can view living cells
+ coloured image
+ does not require heavy staining
-Specimens must be thin enough
-Low resolution (200nm)
Evaluate the use of an electron microscope
+ Short wavelength so has a very high resolution (0.2-10nm)
+ high magnification
-Cannot see living organisms
-black and white images
-prepping is difficult
Organelles that can be seen by an electron microscope
- Endoplasmic reticulum
- Ribosomes
- Vacuoles
