Cell Organelles Flashcards
What occurs in the Endoplasmic reticulum
Protein synthesis,
Lipid synthesis, protein folding, and storage of calcium
What occurs in the Golgi apparatus
Post-translational changes of proteins and lipids, and trafficking
What is the mitochondria responsible for
Making ATP
Signaling
Cell differentiation
Cell death
What is the peroxisomes responsible for
Small vesicular compartments that contain enzymes used in redox reactions
Two kinds of eukaryotic cells
Liver hepatocytes and pancreatic exocrine cells
In pancreatic exocrine cells, what type of membrane makes up the greatest percent of the cell
Rough ER membrane (about 60%)
*lots of protein synthesis
In liver heptaocytes cells, what membrane makes up the largest percent
Inner membrane mitochondria (32%)
*lots of energy being made
What are the three topoligical categories of cells
- Nucleus and cytosol
- communicate through nuclear pores
- ER, golgi, endoscopes, and lysosomes
- communicate through vesicles
- Mitochondria
Membrane _____ and ______ allows the lumen of the cell compartments to communicate with each other and with the cell exterior
Budding and fusion
What are the structural components of the ER
Cisternae (flat sacs)
Tubules
Vesicles
The ER divides the cytoplasm into what two compartments
- Luminal or cistern all compartment
2. Cytoplasmic or cytosolic compartment
Important functions of the Rough ER
- Proteins are modified and assembled
- Segregation of proteins for intracellular use
- Export from the cell (collagen, cell membrane proteins)
*cells that make a lot of secreted proteins have a lot of RER
The mechanism by which secretory proteins are directed to the endoplasmic reticulum is explained by the _________ ________
Signal sequence
T/F
Most proteins exit the Golgi Apparatus in vesicles transported to the cis portion of the RER
False
Exit the RER and sent to the Golgi apparatus
Important functions for the Smooth ER
- Glycogen metabolism
- Lipid synthesis
- Phospholipid synthesis
- Detoxification
- Steriodogensis
- Calcium regulation
**abundant in cells that make STEROIDS or LIPIDS
2 ways the RER and SER are different
- SER lacks ribosomes
2. SER has tubular cisternae and the RER has flat elongated cisternae
Each Golgi stack (in the Golgi apparatus) has two distinct faces: an _____ face and an ____ face
Entry (cis) face
Exit (trans) face
*the CIS Golgi is adjacent to the ER and the TRANS Golgi points toward the plasma membrane or nucleus
Main functions of the Golgi apparatus
- Modifications of carbs
- Polysaccharide and oligosaccharide synthesis
- Shingomyelin and glycosphingolipid synthesis
- Sorting of secretory products (*MARKING LYOSOSMAL ENZYMES WITH MANNOSE 6 PHOSPHATE)
- Packing and storing secretory products into granules or vesicles
The Golgi disassembles in _______ and reassembles in ________
- Mitosis/ meiosis
2. Interphase
The vesicular transport mechanism (by continual budding and fusion) involves what two types of. Coated vesicles
- Clathrin-coated vesicles
3. COP-coated vesicles (COat Protein)
Which vesicle type transports products from the golgi to lysosomes or products from the exterior of the cell to lysosomes (like cholesterol)
Clathrin-coated vesicles
**transport vesicles coated by the protein clathrin which are seen in the exocytosis/secretory and endocytosis pathway
What vesicle type transports products between stacks of the golgi COPI-coated vesicles and ER to the golgi COPII-coated vesicles
COP-coated vesicles
What mediates clathrin binding to the vesicle membrane
Adaptins
Membrane-enclosed organelles that contain 50-60 hydrolytic enzymes are most active at _______ pH that is capable of breaking down proteins, carbs, fats, and nucleic acids
Acidic pH
What is the recycling system of the cell
Lysosomes
Lysosomes contain an ____________ to maintain an acidic environment
ATP-dependent H+ pump
Describe primary lysosomes
The storage site of lysosomal hydro leases
- no digestive events - homogenous - inactive enzymes
Describe Secondary lysosomes
Engaged in catalytic process
- digestive enzymes - heterogeneous - active enzymes
What are the 3 pathways for intracellular degradation
- Phagocytosis
- Autophagy
- Receptor-mediated endocytosis
How are lysosomes formed
From fusion of transport vesicles with Endosomes
Clathrin components recycled and early endosomes mature into late endosomes which are precursors of secondary lysosomes
What is familial hypercholesterolemia
- mechanism of cholesterol uptake is disrupted
- elevation of LDL (main cholesterol transport protein)
- primary defect is mutation in the LDL receptor encoding gene
**high LDL levels leads to atherosclerotic plaques
What cells form H2O2, which is immediately broken down by catalase
Peroxisomes (micro bodies)
What are the main function of peroxisomes
Synthesis and degradation of H2O2
B-oxidation. Of LCFA’s
Synthesis of bile acids and cholesterol
Detoxify alcohol
Zellweger spectrum disorder (ZSD)
Peroxisomes biogenesis disorders caused by defects in the assembly of peroxisomes by at least one defect of the 12 genes that synthesize peroxisomes
Zellweger Syndrome
*Most serious ZSD
Absence or reduced number of peroxisomes in the cells
Resent at birth
No cure or treatment and causes death by one year
T/F
Mitochondria are associated with the microtubular cytoskeleton
True
*make up 20% of cytoplasmic volume
T/F
Mitochondria retain there own DNA
True
