Cell structure Flashcards
Light microscope
wavelength= 400nm, resolution= 200nm
cheap and easy to use
natural colour
magnification= x1500
fluorescent dye stain, coloured chemicals
living and dead specimens
Electron microscope
Electron beam= 0.4nm, resolution= 0.2nm
magnification= x10000
metal particles as stain
dead specimens as they are put through vacuum and stain kills
black and white, difficult, very expensive
SEM (scanning EM)
resolution= 3-10nm
magnification= x100000
3D images, bounces off surface
TEM (transmission)
resolution= 0.2nm
magnification= x500000
2D image, transmitted through
What happens in staining in light microscopy
Fixing- formaldehyde, used to preserve specimens
Sectioning- dehydrated with alcohols and placed in wax or resin, then sliced thinly with a knife (allow light through)
Staining- using coloured chemicals or dyes to be able to see specimens, methylne blue, acetin ocein
Mounting- secured to microscope slide and cover slip placed on top
Differential staining- distinguish between two types of organisms/ different organelles
Organelle
Structure in a cell that has a specialised function
Organelles working together is called division of labour
Different organelles have different functions
Ultrastructure
Detailed structure of the internal components of cells as revealed by electron microscope
Ultrastructure of an animal cell
Golgi apparatus
Cell surface membrane
lysosomes
smooth ER
rough ER
mitochondria
nucleolus
nucleus
microvilli
ribosome
nuclear pores
nuclear envelope
centrioles
Ultrastructure of plant cells
Smooth ER
vesicle
permanent vacuole
nucleus
nucleolus
golgi apparatus
mitochondrion
chloroplast
cell surface membrane
cellulose cell wall
Rough ER
ribosomes
Function of smooth ER
Makes lipids
Cells that make steroid hormones have lots of ER
Function of ribosome
Makes proteins
Function of rough ER
Transports proteins made by attached ribosomes
Function of Golgi apparatus
Modifies and packages proteins, makes secretory vesicles and lysosomes
Function of lysosomes
Contains enzymes for destroying worn out organelles and food particles
Function of nucleus
Controls activities of the cell, stores and protects DNA