Chapter 2 (Pt. 2) Flashcards
the _______ is a dense region in the nucleus, associated with ribosomal subunit assembly
nucleolus
is the nucleolus an organelle?
no. not membrane bound
ribosomal subunit is made up of what? (2)
- rRNA (ribosomal RNA)
- proteins
eukaryotic ribosomal subunits are made in the _____ and assembled in the ______
nucleus
cytosol
what do ribosomes do?
synthesis of proteins (translation)
structure of a eukaryotic vs. prokaryotic ribosome?
EU: 80S
PR: 70S
where are ribosomes found? (2)
freely in the cytosol or attached to the rough ER
which type of ribosomes tend to make proteins that function within the cytosol of the cell
free
ribosomes that bind to the rough ER will synthesize proteins that go where?
into the rough ER lumen
rough ER is continuous with the ?
ER lumen is continuous with the ?
outer nuclear membrane
perinuclear space
what happens to proteins inside the rough ER?
they are manipulated
what is a common manipulation for proteins in the rough ER?
glycosylation to make glycoproteins
what are the two fates of proteins that enter the lumen of the rough ER?
- become part of the cell membrane
- exocytosis
smooth/rough ER: synthesizes lipids and steroid hormones for export
smooth
smooth/rough ER: functions in the breakdown of toxins and drugs
smooth
smooth/rough ER: not covered by ribosomes
smooth
smooth ER is usually not attached to the
outer nuclear membrane
ERs send vesicles to the
cis-face of the Golgi
vesicles travel from the _____ to __________ of the Golgi (faces)
cis-face to trans-face
what is the main function of the Golgi apparatus?
directing molecules to their correct locations
which organelles break down nutrients/bacteria/cell debris?
lysosomes
lysosomes receive vesicles containing digestive enzymes from the ?
Golgia apparatus
intracellular breakdown of unneeded/defective cellular components is called
autophagy
lysosomes function in ______ when they release their contents into the cell
apoptosis
which cells have vacuoles?
all __2___
some ___3___
all plants and fungus; some animal, protis, and bacteria
what are the types of vacuoles? (5)
transport
food
central
storage
contractile
____ vacuoles move materials from organelle to organelle or from organelles to the plasma membrane
transport
_____ vacuoles are temporary food holders that eventually merge with lysosomes for digestion
food
central vecuoles have a _ and exert _ when filled to maintain plant cell rigidity
tonoplast; turgor
what is turgor? what causes it?
the pressure exerted by the water inside a plant cell against the cell wall
____ vacuoles (in plants) act similarly to lysosomes and storage vacuoles
central
which vacuoles store starches, pigments, and toxic substances
storage
which vacuoles collect and pump excess water out of single-celled organisms
contractile
contractile vacuoles use ____ transport
active
what is the endomembrane system?
group of organelles/membranes that work together to modify, package, and transport proteins and lipids that are entering/exiting a cell
what are the components of the endomembrane system?
- nucleus/nuclear envelope
- rough/smooth ER
- Golgi apparatus
- lysosomes
- vacuoles
- cell membrane
what breaks down fatty acids and some AAs; also involved with detoxification
perioxisomes
alcohol detoxification occurs in the ____ of liver cells
peroxisomes and smooth ER
are peroxisomes part of the endomembrane system
no
do peroxisomes receive vesicles from the golgi apparatus? why?
no, they are not part of the endomembrane system
peroxisomes generate __, which can produce reactive oxygen species
hydrogen peroxide
reactive oxygen species can create __
free radicals
peroxisomes contain an enzyme called __, which converts dangerous hydrogen peroxide radicals into harmless water
catalase
what makes ATP in all eukaryotes?
mitochondria
what carries out photosynthesis in select euaryotes?
chloroplasts
centrosome is an organelle found near the what of animal cells?
nucleus
centrosome contains a pair of __, which work together to serve as __ during cell division in animal cells
centrioles; microtubule organizing centers
what aids in cell structure, function, and movement in prokaryotes and eukaryotes
cytoskeleton
the cytoskeleton is found within the __ of prokaryotes/eukaryotes
cytoplasm
what are the three components of eukaryotic cytoskeletons?
microfilaments
intermediate filaments
microtubules
which has the smallest diameter out of the three cytoskeletal components
microfilaments
microfilaments are made of a double helix of two __ filaments
actin
the actin monomers of a microfilament have __, so the microfilaments do too
directionality
actin can undergo rapid _, which makes microfilaments useful for cell movement
assembly/disassembly
what are some examples of cellular processes that rely upon microfilaments?
amoeboid movement; cyclosis; cleavage furrow formation; muscle contraction
intermediate filaments have a diameter ____ the other two cytoskeletal components
between (intermediate to)
which filaments provide cytoskeletal support for maintaining cell shape, and are also found in the nuclear lamina
intermediate
which is the most common type of protein found in intermediate filaments?
keratin
keratin is found in
skin, hair, nails
intermediate filaments do not undergo _, so they are longer lasting
rapid assembly/disassembly
