B.2.2 SL Flashcards
Explain how organelles are subunits of the cell.
The plasma membrane itself is considered an organelle. Organelles are discrete structures in the cell. They are enclosed within the cell membrane and work together to maintain cellular processes. Their form facilitates their function and they each have separate functions. Some structures within the cell are not organelles such as:
- Cell wall: outside of the cell so its not inside
- Cytoplasm: not specialized to perform a specific function
- Cytoskeleton: quite large (hahaha) not discrete
Explain ultracentrifuges.
This progress in science allowed for development of new techniques and for the study of the function of individual organelles only possible after ultracentrifuges were invented.
The process through which samples undergo in ultracentrifuges is:
1. Cells are disrupted in a blender
2. It is centrifuges step by step increasing centrifuge force
3. The denser material will form a solid pellet at the base of the centrifuge
4. The supernatant can undergo repeated centrifugation at progressively higher speeds
State the advantages of the separation the nucleus and the cytoplasm.
Eukaryotic cells evolved through infolding and endosymbiosis to become efficient spaces where multiple activities happen.
They contain many membrane bound organelles which create a compartment with controlled conditions. These compartments are different from the environment and tailored to the specific functions of the organelle. They have the resources energy and space needed.
State the advantages of compartmentalization.
compartmentalization is the organisation of a cell into many different compartments (organelles). Some of the advantages are:
- Enzymes and metabolites can be concentrated in a small space increasing the chance for collision between active site and substrate
- Substances that can damage cells can be isolated within a membrane to protect others
- Conditions such as pH can be maintained at an optimal value for a particular reaction
- Large areas of membrane can become dense with proteins for specific processes (specialized)
