chloroplasts, apoptosis, endomembranes Flashcards
-chloroplasts and photophosphorylation -mitochondria and programmed cell death -the endomembrane system and trafficking
what is oxidative phosphorylation
app synthesis in the mitochondria
describe light dependent reactions
- occur in thylakoid membrane
- chlorophyll in light harvesting complex
- electrons enter ETC
- H+ pumped into thylakoid lumen
where do light dependent reaction occur
light dependent reactions occur in thylakoid membranes
chloroplasts have how many membranes
chloroplasts have 3 membranes
what are the three membranes of chloroplasts
inner, thylakoid, outer
where is the lumen
in the thylakoid membrane
where is chlorophyll found
light harvesting complexes
describe light-independent reactions
(dark reactions, Calvin cycle)
- occur in stroma
- ATP (and NADPH) made in light reaction used to make CH2O
what is another term for light-independent reactions
dark reactions or Calvin reactions
what is used to make CH2O
in independent-light reactions, ATP or NADPH is used
what is apoptosis
programmed cell death
how is apoptosis characterized
- shrinkage of cells
- blebbing of plasma membrane
- fragmentation of DNA and nucleus
- loss of attachment to other cells
- engulfment by phagocytosis
describe the intrinsic pathway of apoptosis
- initiated by intracellular stimuli (such as genetic damage, hypoxia, or a virus)
- “killer” proteins stimulate mitochondrial to leak protein (cytochrome c)
- release of apoptotic mitochondrial proteins commits the cell to apoptosis
how is apoptosis initiated
apoptosis is initiated by internal stimuli
like things such as genetic damage, hypoxia, or a virus
“killer” _____ stimulate mitochondria to leak proteins
killer proteins stimulate mitochondria to leak proteins
what commits the cell to apoptosis
release of apoptotic mitochondrial proteins commit the cell to apoptosis
what does caspases lead to
disrupts cell adhesion
destroys laming
activates DNase (genome breakdown)
breaks down cytoskeleton
describe the cytoplasmic membrane system
- membrane bound organelle and vesicles
- etensive network of membranous canals and stacks of “sacks” (cisternae)
describe the polarized structure of a secretory vesicle
- secrete protein (mucin, a glycoprotein component of mucus)
- synthesized in rough er
- produced in er
- further processed in Golgi
- concentrated in vesicles
- delivered to plasma membrane
where are secretory proteins synthesized
secretory proteins are synthesized in the rough er
where are secretory proteins processed
smooth er and then further processed in the Golgi
where are secretory proteins stored
secretory proteins are tiered in vesicles, awaiting delivery to plasma membrane
describe two pathways of vesicular transport
1) organelle -> plasma membrane (and rise versa)
2) organelle->organelle
describe transport vesicles
small, spherical,membrane-enclosed organelles that bud off sonar compartment and fuse with acceptor to recipient compartment
four steps of trafficking vesicles to a compartment:
1) movement of vesicle
- uses cytoskeleton and motor proteins
2) tethering vesicle to target compartment
- via proteins called RABS and tethering proteins
3) docking of vesicle to target compartment
- using SNARE proteins
4) fusion of vesicle and target membrane
short hand of vesicular traffic
the membrane protein (fused to GFP) starts in th ER, gets concentrated in the Golgi, and then shows up at PM
how does the membrane jump from compartment to compartment
-orientation of a transmembrane protein with respect to the cytoplasm and the interior of membrane-bound compartments is maintained during it travel through the endomembrane system
what is excotysis
organelle-> PM
what is endocytosis
PM-> organelle
the smooth ER lacks ___ and is the primary site of ______
the smooth ER lacks ribosomes and is the primary site of lipid synthesis
functions of the smooth er
- lipid synthesis
- production of steroid hormones (endocrine cells)
- detoxification (eg in liver cells)
- contains enzymes that modify foreign compounds
- storage of calcium
what is the smooth er called in muscles
sarcoplasmic reticulum
what are capsizes
proteins that activate proteins that are involved in dismantling the cell
main use of apoptosis
eliminates redundant or damaged cells
not enough apoptosis is associated with ?
cancer
too much apoptosis is associated with ?
neurodegenerative diseases
what does the endomembrane system mediate
the endomembrane system membrane mediates exocytosis and endocytosis via vesicular transport
photophosphorylation
creates ATP and NADPH
