Lecture 18 Flashcards
What is apoptosis?
an important, regulated process that eliminates redundant or damaged cells.
- plays a big role in plant growth
- plants use programmed cell death to generate holes in leaves
Cytoplasmic endomembrane system
- early EM focusing on cytoplasm revealed membrane-bound organelles and vesicles as well as extensive network canals and stacks of sacs
What are SNARES?
- assembly provides NRG fro fusion
What are killer proteins?
- proteins like BAX cause change in mitochondria membrane potential and to leak cytochrome
What are light-dependent reactions?
- occurs in thylakoid membrane: e- enters ETC
- chlorophyll in light harvesting complex
- H+ pumped into thylakoid lumen
- ATP and NADPH made used to make CH2O in light-independent reactions
Key features of vesicular trafficking
- movement of vesicle- uses cytoskeleton and motor proteins
- tethering- vesicle to target compartment through proteins from Rab family of protein and other more specialized
- Docking- vesicles to target compartments and use proteins called SNARES
- fusion- vesicle and target membrane
Events to have a polarized structure of a secretory cell
- synthesized in rough ER
- processed in ER
- further processed in Golgi
- contracted in vesicles
- delivered to plasma membrane for secretion
What is vesicular transport/ trafficking?
- transport of material between compartments
- organelle ⇌ PM
- organelle ⇌ organelle
- utilizes transport vesicles
Apoptosis and diseases
- various diseases are associated with apoptosis
- sometimes too little apoptosis: cancer malignant cells won’t die
- sometimes too much apoptosis: Alzheimers and Parkinsons disease
What is exocytosis?
- secretion of neurotransmitter
- Ex. organelle → plasma membrane
What is endocytosis?
- activity-dependent internalization of AMPA receptors
- Ex. plasma membrane → organelle
What is programmed cell death/ apoptosis?
- normal process involving cell deaths in coordinated event sequence
- part of organisms growth/development
What are light-independent reactions?
- dark reactions/Calvin cycle
- occur in stroma of chloroplasts
ATP and NADPH used to make CH2O
Intrinsic Pathway of Apoptosis
- initiated by intracellular stimuli like genetic damage, hypoxia, viruses
- release of apoptotic mitochondria proteins commits cell to apoptosis
- release of chromosome c and nuclear fragmentation during apoptosis
What are utilized transport vesicles?
- small, spherical, membrane-enclosed organelles that bud off donor compartment and fuse w/ acceptor or recipient compartment
What are the targeted movement of vesicular transport/ trafficking?
- uses cytoskeleton and motor proteins
- sorting signals recognized by receptors
Apoptotic cell characteristics
- shrinkage of cell
- bleeding of PM
- fragmentation of DNA and nucleus
- attachment loss to other cells
- engulfment by phagocytosis
GFP to track cell components
- Green Fluorescent Protein from jellyfish can be fused w/ other cellular proteins
- fusion protein can be expressed in cells
- cellular GFP fusion protein= visualized under microscope
- observing fusion provides info on endogenous protein
How can GFP be used to track the movement of membrane proteins?
Add GFP to N or C terminus of protein of interest; ie; make a fusion protein
