Cell Structure Flashcards
(16 cards)
Plasma membrane
Made mainly of lipids and proteins
Regulates movement in and out of the cell
Has receptors used in cell signalling
Cell wall
Cellulose in plants
Chitin in fungi
Peptidoglycan in prokaryotic
Supports the shape
Nucleus
Surrounded by nuclear envelope
Contains chromatic and nucleolus
Controls cells activities
Codes for proteins
Nuclear pores allow movement between nucleus and cytoplasm
Nucleolus makes ribosomes
Lysosome
Contains digestive enzymes
Digest invading cells or break down worn out components
Ribosome
Made up of proteins and RNA
Proteinsynthesis
Protein production organelles
Rer ribosomes make extracellular proteins
Free floating ribosomes make intracellular proteins
Transported to golfing apparatus to be further processed
Proteins enter vesicles to be transported
Cytoskeleton
Support cells organelles
Strengthen cell to maintain shape
Move materials within cell (chromosomes)
Form cilia and flagella for movement of whole cell
Prokaryotic cells
<2um diameter
Circular DNA
Peptidoglycan cell wall
No membrane bound organelles
Flagellin flagellation
70s ribosomes
Eukaryotic cells
10-100um Diameter
Linear dna in nucleus
Membrane bound organelles
9+2 flagella arrangement
80s ribosomes
Magnification
How much bigger the imag3 size is than the actual size
Image size= magnification × actual size
Resolution
How detailed the image is
How well it can distinguish between two points that are close together
Light microscope
Lower resolution (0.2um)
View whole cells or tissues
Max magnification ×1500
Staining using inorganic ions
Coloured image of living sample
Transmission electron microscope
Electromagnets
Denser regions appear darker
High resolution 0.0002um
Magnification ×1000000
Visualise internal structures
Black and white imaging of dead cells
Heavy metals staining
Scanning electron microscope
Scan beam over specimen surface
3D image of surface produced
Black and white image of dead cell
Lower resolution than tem 0.002um
Magnification ×500000
Importance of staining
May be transparent specimen
Creates contrast
Different stains effect different organelles so multiple can be used
Eyepiece graticule and stage micrometer
Line up epg and sm
Sm divisions are 0.1mm
Size of one division= 0.1÷ number of epg divisions
