Cells
- Created by: emma
- Created on: 17-04-14 15:23
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- Cells
- Organelles in eukaryotic cells
- Nucleus- contains genetic information (DNA), controls cell
- Mitochondria- site of ATP production from aerobic respiration, double membrane cristae and matrix
- Rough endoplasmic reticulum- Transports proteins through cell, has ribosomes
- Smooth endoplasmic reticulum- synthesis of lipids, doesn't have ribosomes
- Golgi apparatus- sorts, processes and packages proteins, can form lysosomes
- Ribosomes- protein synthesis
- Lysosomes- Contain digestive enzymes and break down unwanted structures
- Microvili- increase surface area of cell
- Cell membrane- controls passage of molecules in and out of cell
- Prokaryotic cell
- DNA circular, not associated with proteins
- Contain no membrane bound organelles
- Has no nucleus
- Contains 70s ribosomes
- Has a capsule, flagella
- Contains 70s ribosomes
- Has no nucleus
- Contain no membrane bound organelles
- DNA circular, not associated with proteins
- Eukaryotic cell
- DNA linear, associated with proteins
- contain membrane bound organelles, mitochondria, golgi
- Has a nucleus
- Contains 80s ribosomes
- Don't have capsule, flagella
- Contains 80s ribosomes
- Has a nucleus
- contain membrane bound organelles, mitochondria, golgi
- DNA linear, associated with proteins
- Microscopes
- Resolution- the ability to distinguish between objects that are close together
- Electron microscopes have better resolution than light microscopes as they have shorter wavelenghts
- Light microscope
- Low resolution but produces colour image, specimens can be alive, low cost
- Electron microscope
- High resolution but specimens must be dead, black and white image only, high cost
- SEM
- Produce 3D image but lower resolution
- TEM
- Produc 2D image but higher resolution
- Image size= Magnification * object size
- Resolution- the ability to distinguish between objects that are close together
- Cell fractionation
- 1)Homogenised to release cell oragnelles
- In an ice cold, isotonic buffered solution
- ice cold- reduce enzyme activity
- Isotonic- stop the net movement of water in and out of organelles to prevent them bursting or shrinking
- Buffered- stop PH changes that could denature proteins
- In an ice cold, isotonic buffered solution
- 2) Mixture is filtered to remove cell debris
- 3)Centrifuged at a low speed so large organelles are forced into pellet at bottom and can be remmoved
- 4) Centrifuged at a high speed so small organelles are forced into pellet at the bottom and can be removed
- 1)Homogenised to release cell oragnelles
- Organelles in eukaryotic cells
- In an ice cold, isotonic buffered solution
- ice cold- reduce enzyme activity
- Isotonic- stop the net movement of water in and out of organelles to prevent them bursting or shrinking
- Buffered- stop PH changes that could denature proteins
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