B: Apoptosis, Endomembranes (18) Flashcards
What is apoptosis
Programmed cell death
Is apoptosis “normal”
Yes, it is a Normal process that involves death of cells in a coordinated sequence of events
Part of an organism’s growth or development
Give an example of apoptosis
Ex. interdigital cell death leads to regression of soft tissue between embryonic digits in many variable
Give an example of a mutation affecting apoptosis
Ex. Bone morphogenetic protein (bmp)
Bmp is a secreted protein that binds to Bmp receptors (BmpRs)
Expression of non-active BmpRs in chicken embryonic hind limbs greatly reduced integral apoptosis and result in webbed feet
Mutant disrupts apoptosis
Is apoptosis used in plants, if yes, how so?
Yes, it plays a role in the growth of plants
Plant uses programmed cell death to generate holes in leaves
What 6 things is apoptosis categorized by
- Shrinkage of cell
- Blebbing (bulge or protrusion) of plasma membrane
- Fragmentation of DNA and nucleus
- Loss of attachment to other cells
- Engulfment of phagocytosis
- Different enzymes become activated and start chewing things down
What initiates apoptosis
Initiated by intracellular stimuli like genetic damage, hypoxia, virus
What causes apoptosis after the initiation factors
Release of apoptotic mitochondrial proteins commits the cell to apoptosis
What are capsizes
Family of endoproteases that provide critical links in cell regulatory networks, controlling inflammation and cell death
What are the role of capsizes (5)
- Release of cytochrome c and nuclear fragmentation during apoptosis
- Disrupts cell adhesion
- Destroys lamins (nuclear filaments)
- Breaks down cytoskeleton
- Activated DNase (genome breakdown)
How is cancer related to apoptosis
Cancer: too little apoptosis occurs, riesling in malignant cells that won’t die
How is Alzheimers related to apoptosis
Alzheimers and parkinsons disease: too much apoptosis, causing degenerative diseases
What is EM bio
Endomembrane biology
What did early EM focus on
Early EM (endomembrane) biology, focused on:
- cytoplasm
- membrane bound organelles
- vesicles
+ extensive network of membranous canals and stacks of sacs (cisternae)
What are the components of the endomembrane (5)
Endoplasmic reticulum (ER)
Endosomal transport vesicles
Golgi complex
Lysosomes
Vacuoles
Explain the process of secreated protiens in the EM
Synthesized in rough ER
Processed in ER
Further processed in golgi
Concentrated in vesicles
Delivered to plasma membrane for secretion
What is GFP
green fluorescent protein (GFP)
How can GFP be used to track well components
- The green fluorescent protein (GFP) from Jellyfish can be fused with other cellular proteins
- The cellular:GFP fusion protein can be visualized under a microscope
- Observation of the fusion protein provides info about endogenous protein (eg. where it is localized in the cell or organism)
How are materials transported between compartments in: Vesicular Transport/Trafficking
Transport of material between compartments
Organelle - plasma membrane (and vise versa)
Organelle to organelle
How are transport vesicles utilzed in: Vesicular Transport/Trafficking
Small, spherical, membrane enclosed organelles that bud off donor compartments and fuse with acceptor or recipient compartment
How is targeted movement directed in: Vesicular Transport/Trafficking
Targeted movement (directed)
Uses cytoskeleton and motor proteins
Sorting signals recognized by receptors
What are the 4 components of vesicle trafficking to a compartment
- Approach
- Vesicle tethering
- Snare assembly
- Fusion
Explain the first component of vesicle trafficking: approach
Movement of vesicle - uses cytoskeleton and motor proteins, can be anterograde or retrograde
Antero = forward, retro= backward
Explain the second component of vesicle trafficking: vesicle tethering
Tethering vesicles to target compartment - via proteins from Rab family of protein and others more specialized
