Wk1 L2 - Cell Ultrastructure Flashcards
1
Q
LO
A
- To understand and be able to recognise in light and electron micrographs, cellular organelles including - ribosomes, smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria and nucleus
- To describe the major functions of the cellular organelles and to relate these to structure
- To understand, describe and be able to recognise the plasma membrane and cytoskeleton in light and electron micrographs
2
Q
Plasma membrane
A
- Cell membrane
- Trilaminar
- 8-10nm
3
Q
Plasma membrane under EM
A
- Can see the microvilli on the apical plasma membrane
- Can see trilaminar appearance
4
Q
Plasma membrane under LM
A
- Stained
- Can see apical and total plasma membrane sections
5
Q
A
6
Q
Fluid mosaic model
A
- Bilayer of phospholipids
- Cholesterol
- Protein molecules (in lipid rafts)
- Dynamic structure
7
Q
Membrane and vessicular transport
- Movement of molecules
A
- Diffusion
- Channels
- Carrier proteins
- Endocytosis
- Exocytosis
8
Q
Cytoplasm
A
- Mainly aqueous solution where physiological processes occur
9
Q
Nucleus
A
Chromatin-DNA
Nucleolus-rRNA
Nuclear membrane
10
Q
Nucleolus
A
- Non-membranous region of nucleus
- Nucleus nan have more than 1
- Full of Ribosomal RNA
- Ribosome production
11
Q
Nucleus - Chromatin
A
- Nucleo-protein complex (histones)
- Basophillic staining
- DNA & structural proteins
- Densely packed DNA into chromatin with Histones
12
Q
Heterochromatin
A
- Densely packed chromatin showing up as darker areas under EM
- Tightly packed chromatin, less active
13
Q
Euchromatin
A
- Light areas of chromatin in nucleus
- Unwound, active and being transcribed
14
Q
Membranous organelles
A
Rough ER
Smooth ER
Ribosomes
Golgi Aparatus
Mitochondria
15
Q
Non-Membranous Organelles
A
Cytockeleton
Microtubules
Microfilaments
Intermediate filaments
16
Q
Rough ER
A
- Free or associated with Rough ER
- Basophilic staining (blue)
- Cisternae structure
- Interconnected flattened sacs
- Ribosomes on membrane for protein synthesis
17
Q
Ribosomes
A
- Dark dots on EM
- Free or associated with Rough ER
- Protein synthesis
- 15-20nm diameter
18
Q
Smooth ER
A
- Eosinophilic staining (blue)
- Tubular
- Lipid and steroid synthesis
- Membrane formation and recycling
- Detoxification (Lots in liver)
19
Q
Golgi Aparatus
A
- Usually pale even though high membrane
- Post-translational modification (tells cells where to go)
- Lots of vesicles associated
- Polarised
20
Q
Mitochondria
A
Mobile power generator
- ATP production
- Move around the cell
- Outer membrane
- Intermembrane space
- Inner membrane
- Matrix
- Cristae
21
Q
Microtubules
A
- Largest of intercellular fibres
- 20-25nm diameter
- Quick assemble and dissassemble
- Transport of vesicles
- Cell migration
- Make up cillia and flagella
- Used in cell division
22
Q
Centrioles
A
- ‘cell centre’
- Made up of 9 microtubule triplets
- Occur in pairs 90º to eachother
23
Q
Microfilaments
A
- Smallest of the intercellular fibres
- Myosin (15nm diameter)
- Actin (6-8nm)
- Thinner, shorter and more flexible than microtubules
- Quick assemble and disassemble
24
Q
Intermediate filaments
A
- 8-10nm diameter
- Intermediate size between microfilaments and microtubules
- Structural role in the cell
- Associated with cell to cell junctions
- Cytokeratins, vimentin
