Cell Orgnells Flashcards
What is the plasma membrane and what are its functions?
Outer body of the cells, bilayer.
-Protective barrier, has transporters, signaling
What is the nucleus and what are its functions.
The nucleus contains the genome.
It is the principle site for DNA and RNA synthesis.
What is the cytoplasm and what is its function.
The cytoplasm consists of cytosol and cytoplasmic organelles.
-Intermediary metabolism
What is the Endoplasmic Reticulum (ER) and what are its functions?
-Ribosomes attached-(Rough ER)
-No Ribosomes - (Smooth ER)
It is involved in protein synthesis, lipid synthesis, protein folding, and storage of calcium.
What is the GOLGI APPARATUS and what are its functions.
The golgi apparatus is composed of stacks of disc-like compartments.
-It is involved in post-translational changes on proteins and lipids, trafficking
Mitocondria and what are their functions?
Outer and inner membrane and matrix.
Mitochondria are involved in making ATP, signaling, cell differentiation, and cell death.
What are lysosomes and what is their function?
Lysosomes contain digestive enzymes that degrade organelles and biomolecules
What are peroxisomes and what is their function?
Peroxisomes are small vesicular compartments that contain enzymes used in oxidation reactions
What are the three topological compartmentalization categories?
#1 Nucleus and cytosol -(communicate through nuclear pore complex) #2 Organelles in secretory and endocrine pathways (ER, Golgi apparatus, endosomes, and lysosomes) - (Communicate through vesicles) #3 Mitochondria
What does membrane budding and fusion allow topological equivalent organelles to do?
communicate with each other and with the cell exterior
Rough Endoplasmic Reticulum
-Parallel sacks of flat, elongated cisternae, studded with ribosomes.
-Functions include:
Protein modification and assembly
Segregation of proteins for intracellular use
Export from cell (ciollagen, cell membrane proteins)
What do cells that make secreted proteins have a lot of?
Rough ER
The mechanism by which secretory proteins are directed to the ER is explained by the what?
Signal sequence
In what do most proteins exit the RER and where are they usually transported to?
Most proteins leave in vesicles and are transported to the cis portion of the Golgi apparatus
How does the SER differ from the RER
The SER lacks ribosomes and has tubular cisternae
What are important functions of the SER
glycogen metabolism, lipid synthesis, phospholipid synthesis, detoxification, steroidogenesis, calcium regulation
Where do the cis and trans section of the golgi apparatus face?
Cis is adjacent to the endoplasmic reticulum
Trans points to the plasma membrane or the nucleus
What are the functions of the golgi apparatus?
- modification of carbs
- polysaccharide and oligosacchride synthesis
- synthesis of sphingomycin and glycosphingolipids
- Sorting of secretory products (marking w/ M6P)
- packing ans storing secretory products
When does the golgi apparatus disassemble? and reassemble?
- disassembles during mitosis/meiosis
- reassembles in interphase
Clathrin-coated vesicles
transport products from GOLGI to lysosomes
*seen in exocytosis/secretory and endocytosis pathway
COP-coated vesicles
transport products between stacks of golgi apparatus and from ER to golgi apparatus
What couses vesicles to pinch off from the plasma membrane
Dynamin
Primary lysosomes
the storage site of lysosomal hydrolases.
- no digestive events
- homogeneous
- inactive enzymes
Secondary lysosomes
Engaged in catalytic process
- digestive enzymes
- heterogeneous
- active enzymes
