chapter 7 - cell systems

what does the nuclear envelope do?

it seperates the nucleus from the rest of the cell

what does the nuclear pore complex do?

it connects the nucleus to the cytoplasm and allows selective transport

what is nuclear transport?

it is the information center of the eukaryotic cells

what goes in and out of the nuclear pore complex?

nuceloside triphsophates and proteins goes in and mrna and ribosomes go out

how is transport regulated?

through observation which is when certain proteins are concentrated in the nucleus

what contains a zip code?

nuclear proteins

what does the zip code do?

the molecular address tags that tell the proteins where to go in the cell

what happens in the endomembrane system?

proteins are synthesized in the rough er, then they travel through the golgi for processing, and then they travel to the cell surface

where does recycling occur?

in the lysosome

what happens during cellular recycling?

so much energy is put into making the macromolecules

what are the three recycling methods and their functions?

endocytosis - uses receptors to bind to macromolecules outside the cell, phagocytosis - it brings smaller cell particles inside the cell to form a phagosome, and autophagy - it encloses a damaged organelle within a membrane to form an autophagosome

what is the cytoskeleton and what does it do?

it is a dense and complex network of fibers that helps maintain cell shape by providing structural support

whatt three distinct filaments does the cytoskeleton contain?

actin, intermediate filaments, and microtubules

what is actin?

they are individual strands that polymerize, wrap around each other, and are found in bundle just inside the plasma membrane

what are examples of movement caused by actin - myosin interactions?

cytokinesis in animals and cytoplasmic streaming in plants

what are intermediate filaments include?

keratins, nuclear lamins, and a flexible cargo net inside the cell

what are nuclear lamins do?

they form a mesh inside the nuclear envelope to anchor chromosomes

what is the largest cytoskeletal component?

microtubules

what is the microtubules function?

they are the framework for organelles, they provide structural support, and they track for vesicle transport

what does bacteria move their entire cells with

flagella and cilia

what is the process for protein sorting and vesicle transport?

1. proteins bound at different destinations and carry distinct tags

2. proteins are sorted

3. transport vesicles bind

4. transport vesicles attach and fuse at the destination

5. vesicles deliver contents

what is the process for the secretory pathway?

1. the protein enters er

2. the protein exits er

3. the protein enters the golgi apparatus

4. the protein exists the golgi apparatus

5. the protein is secreted from the cell