biology 1 Flashcards
Where is DNA held?
nucleus
A small amount of nuclear DNA is found in the __
mitochondria
What is the nucleolus?
the site of rRNA transcription and ribosome assembly
Where are proteins that are bound to the ER, golgi, lysosomes, endosomes, plasma membrane or secreted outside the cell made?
the RER
Where are proteins that remain in the cytosol made?
free floating ribosomes
Where in the cell are lipids synthesized?
smooth ER
Where are lipids metabolized?
in the mitochondria
What is the function of the golgi apparatus?
organize and distribute proteins, continue post translational modification
How are mitochondrial genes passed down?
maternal side
What is the endosymbiotic theory?
suggests mitochondria evolved from aerobic prokaryotes that were engulfed by a larger host.
Where is the pH higher, the matrix or the inter membrane space of the mitochondria?
matrix has higher pH (protons are pumped into intermembrane space)
What would happen if hydrogen ion channels were placed in the mito mem?
less ATP production because there would be an alternate route from ATP synthase
What is thermogenin?
protein channel in the inner membrane of mito that allows the passage of protons (brown fat)
What are the main functions of centrioles/centrosomes?
centrosome - organizes microtubules, flagella, and cilia (plays key role in cell division)
What is the pH of a lysosome? What is its function?
5, digest cell parts, fuse with phagocytic vesicles, participate in apoptosis
What is the function of peroxisomes?
self-replicate, detoxify chemicals, participate in lipid metabolism
What is tubulin?
a globular protein that polymerizes to form microtubules
What are microtubules?
make up the cytoskeleton, 2 types of tubulin: alpha -tubulin, beta-tubulin
protofilmament- heterodimer
How many protofilaments in a microtubule?
13
What is the cytoskeleton?
scaffolding-like network of microfilaments, microtubules, and intermediate filaments that provides structure to the cell
What is the spindle apparatus?
array of microtubules that grows outwards from the centrioles during mitosis to bind with the centromere of the chromosomes at the metaphase plate
What is actin?
protein monomer that polymerizes to form microfilaments
What is an intermediate filament?
general class of several proteins that polymerize to form filaments that are intermediate in diameter.
What is myosin?
motor protein (9+2) arrangement found in eukaryotic cilia and flagella