2.1 Cell Structure Flashcards
Resolution
The degree to which it is possible to distinguish between two objects that are very close together
Higher resolution - greater detail seen
Magnification
The degree to which the size of an image is larger than the object itself
Cytoskeleton
The network of protein fibres within a cel, that gives structure and shale to the cell and also moves organelles inside the cell
Division of labour
Division of labour describes the organelles each having their own specific roles who thin the cell, to carry out its function
TEM
Transmission electron microscope
TEM resolution and magnification
X500 000
0.1nm
SEM
Scanning electron microscope
SEM magnification and resolution
X100 000
10nm
Organelle
Structures in cells which have a specialised function eg. Nucleus.
Aka sub cellular structures
Size of animal cell
20-40um
Size of plant cells
10-100um
Size of prokaryotic cells
1-5um
Acetic orcein
Stain that dyes DNA dark red under a light microscope
Light microscope magnification and resolution
X1500
200nm
Image size =
Actual size X magnification
Lenses in electron microscopes
Electro magnets used to focus electron beam
Staining in electron microscopes
Heavy metal salts eg. From uranium - uranyl acetate
Cell ultra structure
The detail seen on an electron micrograph of a cell
Micro tubules
Hollow cylinders of tubulin that are the main part of the cytoskeleton
25nm diameter
Role of micro tubules
Maintain cell shape Keep organelles in place Move liquid past a cell Move microbes through a liquid Move vesicles from ER to Golgi apparatus
Flagella and cilia
Structurally the same in eukaryotes but flagella are longer
Cylinder with 9 microtubules in a circle + 2 central microtubules
Cilia
> 10um long
25nm wide
Move to and fro
Eg. Ciliated epithelium of airways
Flagella
Move in whip motion in eukaryotes
Eg, sperm cells
Intermediate filaments
10nm diameter
Thick keratin cables
Maintain cell shape
Anchor organelles in place
Actin microfilaments
7nm diameter 2 intertwined strands of actin Maintain cell shape Involved in cell division (cytokinesis) Cause a movement -Pseudopodia- seen by WBC and amoeba
Vesicle
Membrane bound sac used to carry substances around eg. To Golgi
