Lecture Four : Plasma Membranes and Organelles
9 important questions on Lecture Four : Plasma Membranes and Organelles
What are the Key Organelles in BOTH animal and plant Cells ? What Organelles make them different from one another ?
Animal Cells have lysosomes whereas Plant Cells have a Central Vacuole and Chloroplasts.
Explain Why organelles and subcellular compartments are important in cells ?
Describe the Structure of the Plasma Membrane
- The plasma membrane is a double layer of fat known as phospholipid bilayer which has proteins embedded in it.
- It has a hydrophobic phosphate head, which points to the outside of the cell.
- Also has a hydrophilic tail with fatty acids , which points to the inside of the cell.
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
Explain the importance of the Plasma membrane to cell function
They are selective and permeable, meaning it allows certain molecules and ions that are beneficial to survival, to enter the cell.
Explain the mechanisms of Passive Transport - Simple Diffusion ?
- Only lipid soluble and hydrophobic molecules can diffuse through the membrane but water, ions and glucose can't.
Explain the mechanisms of Passive Transport - Facilitated Diffusion ?
- Channels like aquaporins allow osmosis.
- Carriers undergo a shape change to help guide the molecule and these channels can be gated by charge or chemicals.
- Water, glucose and ions are examples of substances that move through these protein channels in the cell membrane.
What are the different concentrations in Osmosis and its affect ?
- Hypotonic : Low solution of solutes but very high water potential.
- Hypertonic : High solution of solutes but very low water potential.
- Isotonic : Both solutions of solutes and water is equally balanced.
Explain the Mechanisms of Active Transport - Direct Transport & Indirect Transport
- Has a proton pump which is controlled by ATP.
INDIRECT : When the energy source comes from other molecules that are moving down their concentration gradient to power the transport.
- Moves specific substances AGAINST the concentration gradient
Explain the different roles of membrane proteins ?
- SIGNAL TRANSDUCTION
- CELL RECOGNITION
- STRENGTH
- INTRACELLULAR JOINING
- LINKING CYTOSKELETON & EXTRACELLULAR MATRIX
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
![Trustpilot Logo](/images/design_2020/lp/clp-trustpilot-en.png)