cell bio final Flashcards
only _______ actin is expressed in muscle cells
alpha
what are the three mechanisms of active transport?
- coupled transport
- ATP pumps
- light/redox reactions
where does the final shape of collagen happen
outside the cell
what kind of membranes do autophagosomes have?
double membranes
a two headed phospholipid exclusively present in the mitochondrial membranes. It is found in many bacterial membranes.
cardiolipin
kinesin walks towards which end of microtubules
plus end
two functions of integrins
adhesion (cell to ECM linkage) and signalling
what are the three phases of actin polymerization (ACTIN GROWTH/formation)
- nucleation/lag phase
- elongation/growth phase
- steady state/equilibrium phase
enzymes activated by extracellular signals to cleave specific phospholipids to release short- lived intracellular messages (aka second messengers)
phospholipases
how is mitochondrial DNA inherited
from mother to child
what do cilia and flagella contain (2)
dynein (motor protein) and microtubules
highly polar and negatively charged, has a strong tendency in attracting water molecules that give the matrix a gel-like composition
GAGs
what are cell junctions
cell - cell interations!
what are the three protein extraction methods?
- detergent based lysis
- osmotic shock
- changes in pH
connects actin filament bundle in one cell with that in the next one
adherens junction
what is the largest GAG
hyaluronic acid
movement of substances across the membrane using energy
active transport
cell eating
phagocytosis
nucleates microtubule branching
augmin
chemical bond forming reactions that generate ATP and membrane transport processes
chemiosmotic coupling
describes the structure of the plasma membrane as a mosaic of components including phospholipids, cholesterol, proteins, and carbohydrates
fluid mosaic model
what are the soluble subunits of intermediate filaments
dimers and tetramers
major sterol found in animal cells
Cholesterol
what links cells with the ECM
inegrins (proteins)
during apoptosis PS is externalized to the outer leaflet by
scramblases
where are microtubules nucleated
microtubule organizing center (MTOC)
how does collagen formation start
with a triple helix molecule (3 molecules of collagen form homo or heterotrimers)
what are cytoskeletal filaments made of
big picture: large helical insoluble filaments
zoom in: each filament is made of soluble monomers
The inner mitochondria membrane forms numerous folds which extend into the interior of the organelle, what are the folds called
cristae
are actin-based motor proteins that generates force by coupling ATP hydrolysis to conformational changes
Myosin proteins
what pump uses ATP hydrolysis to drive H + transport
V-type pump
the y tubulin ring complex in microtubules is similar to what in actin filaments
Arp2/3 complex (both nucleation complexes)
how can we visualize actin cytoskeleton in vivo?
incorporating fluorescently labeled actin
ex. staining F-actin in vivo with SiR- Actin, a cell-permeable noncytotoxic compound
yellow or orange pigments
carotenoids
anchors actin filaments in cell to extracellular matrix
focal adhesions/actin-linked cell matrix junction
Anchors intermediate filaments in cell to extracellular matrix
hemidesmosome
cell crawling relies on the
actin cytoskeleton
cell migration in response to soluble factors (concentration gradients of extracellular signals)
chemotaxis
why does the matrix have a slightly higher pH than the cytosol
cristae traps the proton because of its shape, this lets the protons stay close to the ATP synthase and makes synthesis of ATP more effective
encloses the matrix and contains all the protein complexes involved in the electron transport chain and the ATP synthase
inner mitochondrial membrane
cell drinking
pinocytosis
where photosynthesis and the synthesis of ATP takes place
Thylakoid membrane
WHO use the energy stored in concentration gradients to couple the uphill transport of one solute across the membrane to the downhill transport of another
couple transporters
channels only use what kind of transport
passive transport
Four ways of immobilizing specific membrane proteins through protein-protein interactions
- By forming large self-assembled protein aggregates
- By tethering(restricting) them to macromolecular assemblies outside the cell
- By tethering(restricting) them to macromolecular assemblies inside the cell
- By interacting with proteins on the surface of another cell
actin-based structures that act as platforms for the localized release of lytic enzymes that degrade the extracellular matrix (matrix degrading structures)
podosomes and invadopodia
which mitochondrial membrane contains B barrel proteins
outer mitochondrial
virus that uses dynein (and dynactin) and microtubules only
influenza
what are the three functions of accessory proteins in the cell cytoskeleton?
- assembly and disassembly of filaments
- link filaments to cells structures and between each other
- act as a bridge between the cytoskeleton and intra/extracellular signals
dynein walks towards which end of microtubules
minus end
movement of substances across the membrane without the expenditure of cellular energy
passive transport