1.4 Summary Flashcards
1
Q
Nucleus
A
- surrounded by nuclear envelope (double membrane) perforated by nuclear pores
- nuclear envelope continuous with ER
- > houses chromosomes - made of chromatin (DNA and proteins)
- > contains nucleoli - ribosomal units made
- > pores regulate entry + exit of materials
2
Q
Ribosome
A
- two subunits made of ribosomal DNA + ribosomes
- can be free in cytoso; or bound to ER
-> protein synthesis
3
Q
Endoplasmatic reticulum (ER)
-> nuclear envelope
A
- extensive network of mebrane-bounded tubules and sacs
- membrane separates lumen from cytosol
- continous with nuclear envelope
- > smooth ER
- > synthesis of lipids
- > metabolism of carbohydrtes
- > Ca2+ storage
- > detoxification of drugs and poisons
- > Rough ER
- > aids in synthesis of secretory + other proteins from bound ribosomes
- > aids carbohydrates to proteins to make glycoproteins
- > produces new membrane
4
Q
Golgi apparatus
A
- stacks of flattened mebranous sacs
- has polarity (cis and trans faces)
- > Modification of proteins
- > carbohydrates on proteins + phospholipids
- > synthesis of many polysaccharides
- > sorting of golgi products - released in vesicles
5
Q
Lysosomes
A
- membranous sac of hydrolytic enzymes (in animal cells)
- > breakdown of ingested substances, cell macromolecules + damaged organelles for recycling
6
Q
Vacuole
A
- large membrane-bounded vesicle
- > digestion, storage, waste disposal, water balance, cell growth + protection
7
Q
Mitochondrion
A
- bounded by double membrane
- inner membrane has infoldings (cristae)
-> cellular respiration
8
Q
Chloroplast
A
- typically 2 membranes around fluid stroma - contains thylakoids stacked into grana (in cells of photosynthetic eukaryotes, including plants)
- > photosynthesis
9
Q
Peroxisome
A
- specialized metabolic compartment bounded by single mebrane
- > contains enzymes - transfer hydrogen atoms from substrates to oxygen - production of hydrogen peroxide (H2O2) as by-product
- > H2O2 converted to water by another enzyme
