Unit 2 - Endomembrane System - Feb 24/27 Flashcards
Nucleoid
Circular supercoiled chromosome found in only prokaryotes
Motile
self moving, many bacteria are motile due to flagella
Plasmid
small, circular piece of extra-chromosomal DNA
Peptidoglycan
makes up semi-rigid but permeable cell wall that almost all bacteria have and prevents osmotic lysis (hypotonic cell)
All Cells Have
Plasma Membrane
DNA
Cytosol
Ribosomes
Cytoskeleton
Only Some Cells Have
Nucleus
Organelles
Cell Wall
Flagellum/Cilium
Cytosol
aqueous fluid contained by plasma membrane. So densely packed with proteins=jelly-like
Flagellum/Cilium
a membrane covered projection used to create movement
Vacuoles
water-filled organelles that contribute to structural rigidity of plants by maintaining turgor pressure against cells walls
Mitochondria
organelles found in virtually all eukaryotes that harness energy from chemical compounds (e.g., glucose, fats) and convert it into ATP
Chloroplasts
organelles that capture the sun’s energy to synthesize simple sugars through photosynthesis
The Endomembrane System evolved from
inner folds of plasma membrane that pinched off and enclosed DNA, creating eukaryotes.
Endosymbiotic Theory
mitochondria and chloroplasts evolved from engulfed prokaryotes that gave an advantage to the host eukaryotic cell
ZIP CODE Hypothesis
proteins are directed to the correct cellular location by signals within their amino acid sequence. (without specific zip code, default location is cytosol)
Nuclear Envelope
a double-membrane structure that is linked with the ER, supported by a cytoskeletal structure called the nuclear lamina, and gated by multiple nuclear pore complexes (study structure)
Nuclear Pore Complexes (NPCs)
allow selective passage of molecules between nucleus and cytoplasm
The Endomembrane System is and includes?
a set of intracellular organelles interconnected by vesicular traffic. (ER, Golgi, lysosome, endosomes, plasma membrane)
Exocytosis
process where an endomembrane vesicle can fuse with the plasma membrane and deliver contents into extracellular space
Endocytosis
when material from outside cell is brought into vesicle that can fuse with other organelles
Vesicular Transport
when a vesicle can pinch off one membrane and fuse with another (because of lipid bilayer fluidity)
Steps of Vesicular Transport
- lumen (inside donor compartment)
- Budding of vesicle from lumen
- Fusion of vesicle to target compartment
The Rough ER
contains translating ribosomes and is where integral membrane and luminal proteins are synthesized
The Smooth ER
where lipid-y stuff is synthesized
Secretion (exocytosis) and steps?
entire process of vesicular transport out of the cell.
Steps:
1.Proteins from ER
2.secretory vesicle from Golgi
3.vesicles fuse plasma membrane
4.Integral membrane proteins -> plasma membrane proteins
5. Luminal proteins secreted extracellular
