Cells and organelles Flashcards
What is the plasma membrane made up of?
Phosphilipid bilayer
What do integral membrane proteins allow?
The transport of small molecules across the membrane
What do membrane receptors do?
They interact with ligands to initiate a cascade of chemical signals
What is DNA packed as in the nucleus?
Chromatin
What structure is bound by a double membrane
Nucleus
What supports the nucleus’ membrane?
Lamins
What are the 2 functions of mitochondria
Site of ATP synthesis and release cytochrome C to induce apoptosis
What organ does mitochondrial dysfunction effect most?
Brain
What process occurs at the rough ER
protein synthesis
What process occurs at smooth ER
Calcium storage and lipid synthesis
What is the function of the golgi
To sort proteins
Why do lysosomes have an impermeable membrane?
Because they contain hydrolytic enzymes
What disease does lysosome dysfunction cause?
Tay-Sachs disease
What is the function of the cytoskeleton
Supports the plasma membrane
What are the 3 filaments of the cytoskeleton
Microtubules, intermediate filaments and microfilaments
Give an example of microtubule
Cillia and flagellum
What disease is caused by a defect in cillia
Kategeners disease
What is the function of anchoring junctions
Provide mechanical stabiulity to groups of epithelial cells
What does an adherens junction join
Cell to actin
What does a desmosome junction join
intermediate filament to cell
What does a hemidesmosome junction join
intermediate filament to ECM
What can a defective anchoring junction cause?
Cancer
What does a tight junction allow
cell to cell contact
What does a tight junction prevent
Prevents the mixing of membrane proteins and the diffusion if molecules between adjacent cells by creating a barrier
What do GAP junctions allow
The passage of small molecules
Where are GAP junctions found
In most cells
What do GAP junctions connect?
The cytoplasm with adjacent cells
