Cell Biology Flashcards
What is the bilayer of a membrane composed of?
Phospholipids, sphingolipids, cholesterol
What is the structure of microfilaments?
Double strands of actin.
What is the function of microfilaments?
Provide support to the cell and allow the cell to fix its shape.
What is the structure of microtubules?
Alpha and beta tubulin polymerise into protofilament.
13 protofilaments form a tube which can be enlarged.
What is the function of microtubules?
Intracellular movement of organelles.
Which motor protein is involved in anterograde transport?
Kinesins
Which motor protein is involved in retrograde transport?
Dyneins
What allows cilia and flagella to move?
Dyneins
What are cilia and flagellum made from?
Mobile projections of the plasma membrane, made from microtubules.
What is the function of intermediate filaments?
Providing cell strength and support.
What are the functions of RER?
- Membrane synthesis.
- Modifying proteins.
- Quality control (monitors misfoldings).
- Signals stress, usually when secretion is blocked.
How did mitochondria evolve?
An endosymbiotic event where a bacteria was captured by a eukaryote.
What happens when a lysosome ruptures?
Cell self digests (autolysis).
What are degradable proteins tagged with?
Ubiquitin.
What is the structure of a proteasome?
Protein complex arranged in four rings around a central core.
What is the function of peroxisomes?
- Resemble lysosomes.
- Break down fatty acids.
- Synthesise specialised lipids.
What happens if a protein has a signal recognition receptor?
The protein will go the ER, bind to it and be used in membrane synthesis.