Chapter 5 : Eukaryotic cell structure Flashcards
in Eukaryotic cell structures this serves as a transport system to move material though out the cell
Intracytoplasmic membrane complex
What does the cell envelope consist of in a eukaryotic cell envelope ?
plasma membrane with lipid bilayer
- sphingolipids, sterols, and phospholipids
Liquid components where organelles are located
cytosol
In a EU cell what helps keep it organized ?
cytoskeleton
What are the three interconnected filaments ?
Microfilaments ( actin protein)
Intermediate filaments
Microtubules
Functions of actin filaments
move cell structure
change shape
endocytosis
cytokinesis
profile of Intermediate filaments
10 nm
flexible and strong
keratin and vimentin proteins
Profile of microtubules
shaped like a thin cylinder
25 nm in diameter
helical cylinder 13 subunits
protiens a and B- tubulin
Function of microtubules
form spindle fiber
cell movement
maintain cell shape and support
The function of intermediate filaments
Structural role
form nuclear lamina and support nuclear envelope
link cells to form tissues
What is the endocytic pathway ?
movement into the cell from the outside
What is the secretory pathway?
movement out of the cell and within the cell
Functions of the ER ?
hub for molecule sysnthesis and transport
cell membrane synthesis
Ribosomes attach to the outer surface and is important to cells that synthesize lots of proteins, this is the ?
Rough ER
Devoid of ribosomes and important for cells that synthesize lipids?
smooth ER
It is made of flattened, saclike cisternae stacked on each other and packages material to secrete them ?
Golgi apparatus
The forming face closest to the ER Is the trans face and the maturing face farthest from the ER is the cis face t o F
false- Cis closest
Trans- farthest
What are lysosomes?
rough sphere-like organelle enclosed in a single membrane
500 nm diameter
digestion
What kind of digestion enzymes do lysosomes contain ?
Hydrolase- hydrolyzes molecule
Lysosome maintian an acidic environment by pumping protons into their interior T o F?
True
List out the general pathway of how proteins are secreted from cell?
- protiens made go into rough er
- pass through to smooth er
- release by vesicle budded off from ER
- vesicle moves to cis face of Golgi the trans
- proteins are modified to go to the target location
- transport vesicle released from trans face to final destination
If the final destination for the protein is the plasma membrane, one of two secretory pathways can be used:
Constitutive - deleviry but unregulated
Regulated secretory pathway- needs signal before fusing to plasma membrane
How are proteins degraded?
- misfolded/unfolded proteins are targeted by ubiquitin polypeptides
proteasomes recognize the ubi. and destroys proteins
Used by all eukaryotic cells to bring materials into the cell
Endocytosis
What are the two types of vesicles that are pinched off from the plasma membrane?
Pinocytosis- solutes
Phagocytosis- particles
What is receptor mediated endocytosis?
when a ligand binds to a receptor to trigger endocytosis
Uses cell surface protrusions to surround and engulf particles
Phagocytosis
What is Clathrin-dependent endocytosis?
clathrin protein-coated pits that are used to internalize
hormones
growth factors
iron
cholesterol
What is Caveolin-dependent endocytosis?
Caveolin coated vesicles
used for signal transduction
small molecule transport
Phagosomes fuse directly with lysosomes T or F
true
Clathrin coated and caveolin coated veiscles deliver content to late endosomes T or F
False - deliver into early endosomes
Delivery of materials to be digested by a route that does not involve endocytosis describes what process?
Autophagy
what occurs in Macroautophagy ?
non selectively digests and recycles cytoplasmic components
What are autophagosomes?
double membrane materials ready to be digested
Extracellular vesicles can contain …
proteins, lipids, NA
How are extracellular vesicles formed?
by pinching off the membrane to surround their cargo
membrane-bound spherical structure that houses chromosomes, that contains genetic information wrapped around…
histones
what is the purpose of the nuclear pore complex
allow passage of materials to be transported in/out of nucleus
A lipid bilayer membrane that surrounds the nuclues and its outer membrane being surrounded by ribosomes, is what structure?
Nuclear envelope
what is the Nucleolus
site of ribosomal RNA synthesis
Where would you find the direct assembly of rRNA that combines with proteins to form partial ribosomal subunits?
Nucleolus
Eukaryotic Ribosomes are smaller than 70s bacterial and archaeal ribosomes T o F?
False- they are much larger being
80s
Which type of ribosomes synthesize integral membranes or secrete proteins?
RER ribosomes
Which type ribosomes synthesize non secretory / non-membrane protiens
free ribosomes
what is the endosymbiotic hypothesis?
Mitochondria, hydrogenosomes, and chloroplast thought to have been evolved from bacterial cell
Porins are proteins are found where in the mitochondria structure?
Outer membrane
What contains cristae infolding to increase surface area?
Inner membrane of mitochondria
Mitochondrial matrix enclosed by inner membrane contains …
ribosomes
mitochondrial DNA
large phosphate granules
What are hydrogenosomes ?
sm. energy captures in anaerobic
Double membrane
lack DNA
ATP generation usually through fermentation
Where does the site of photosynthetic reaction take place?
chloroplast
Site of dark reactions of photosynthesis and contains organelles like thylakoids?
Stroma
The site of light reaction of photosynthesis?
Thylakoids
Eukaryotic cell have flagella and pili as external structures T o F
False- they have flagella and cilia
