Week 11 Flashcards
____________ are hydrophobic molecules and are usually found in membranes.
Lipids
____________ means can have polar and non polar components.
Amphipathic.
____________ contains two leaflets of phospholipids.
Plasma membrane
_____________ are lipids that contain glycerol backbone.
Glycerphospholipids.
___________ are lipids that contain phosphate groups.
Phospholipids.
____________ are lipids that contain a sphingosine backbone.
Sphingolipids.
_____________ are steroid containing lipids and is added to a membrane to increase fluidity.
Cholesterol.
___________ is the movement of particles down a concentration gradient.
Diffusion.
Diffusion of molecules depends on several factors:
Size
Shape
Temperature
Solvent Viscosity
__________ are proteins embedded in the plasma membrane.
Integral Membrane Proteins
____________ are examples of membrane-spanning proteins.
Seven-Transmembrane Receptors
Seven-Transmembrane Receptors contain seven transmembrane ______________ that span the membrane.
Alpha helices.
_____________ are associated with the surface of the membrane, can be linked through a hydrophobic anchor, and not embedded in the plasma membrane.
Peripheral Membrane proteins
___________ methods for molecules to pass in and out of the cell or organelle.
Transporters.
___________ takes one molecule through the membrane.
Uniporter
____________ takes two different molecules through the membrane.
Symporter
____________ swaps one molecule with the other from the other side of the membrane.
Antiporter.
In ______________ energy is required , molecules move up a concentration gradient, can be primary or secondary.
Active transport
_____________ active transports uses ATP directly to drive ion movement.
Primary
____________ active transports, gradient pumps a second molecule across membrane.
Secondary
In ______________ molecules move down a concentration gradient, can occur through channels.
Passive Transport
A lot of ___________ gated channels are considered uriporters.
Voltage
______________ is the movement of solvent through a semipermeable barrier from a region of low to high solute concentration.
Osmosis
__________ are structures that aggregate in the plasma membrane. They are involved in cell signaling and tethering cell membranes.
Lipid Rafts.
Lipids Rafts are composed of ____________ and ____________.
Cholesterol and sphingolipids.
_______________ is generally accomplished through chemical signals; although some specialized cells can detect and respond to light.
Signal Transduction
Signal binds specifically to the ___________ on the extracellular sides.
Receptor
____________ is a chemical compound released by other cells somewhere in the organism or by other organisms in the environment.
Signal.
___________ is a chemical message made in response to a signal that amplifies and propagates it inside the cell.
Second messenger.
_________ occurs when a common signaling molecule that is active in both pathways.
Cross talk
_____________ is a molecule that generates the second messenger.
Effector.
______________ is a tetramer with 2 regulatory and 2 catalytic subunits.
Protein Kinase A (PKA)
PKA is activated by a signal from a ______________.
Catecholamine
Catecholamine binds to a _____________ receptor and activates heterotrimeric __________ protein.
Beta-adrenergic receptor, G.
____________ subunit exchanges GDP for GTP.
G alpha
G alpha subunit disassociates from the complex and activates _____________.
Adenylate cyclase.
Activated adenylate cyclase produces ___________ from ATP.
cAMP.
cAMP binds to the regulatory subunits of ____________, activating it .
PKA.
______________ will make the G-protein constantly on.
Cholera Toxin
____________ is a peptide hormone, it is a growth factor and regulates glucose levels.
Insulin.
Insulin functions through a receptor called ____________.
Tyrosine Kinase.
Insulin binds to its receptor causing dimerization of the receptor and recruitment of ____________.
IRS-1.
Phosphorylated IRS-1 initiates a phosphorylation cascade, resulting in the activation of __________.
Erk.
Erk alters gene expression via ______________ pathway and Erk.
MAP kinase
IRS-1 activates _____________, which converts ______________ to ______________.
PI3K, PIP2 to PIP3.
PIP3 then activates _____________.
PDK1.
Activated PDK1 phosphorylates _______________.
Akt.
Akt phosphorylates trafficking proteins on _____________ vesicles.
Glut 4.
Glut 4 vesicles translocate to the plasma membrane, increasing _____________ transport.
Glucose.
Akt can phosphorylate ____________, which breaks down cAMP, decreasing PKA signaling.
PDE-3B
Akt can phosphorylate ____________, which increases protein synthesis.
mTOR.
_______________ is a cytosolic kinase that responds to AMP levels and acts as acute regulator of cellular metabolism.
AMP- activated protein kinase (AMPK)
Increased AMP activates ____________ which activates catabolic pathways that break down ____________ which activates ____________ and promotes the storage of carbohydrates.
AMPK, Triglycerides, Beta-oxidation.
What nucleotide is an allosteric regulator of protein kinase A and many other enzymes?
cAMP.
_____________ are typically small, soluble signals that are generated or released within the cell in response to an extracellular signal.
Second messengers
In ______________ , kinase becomes active and phosphorylates a second kinase downstream of the first.
Kinase Cascades.
______________ are enzymes that cleave phosphates from proteins, play a key role in reversing the action of kinases and shutting down kinase signaling cascades.
Phosphatases.
________________ dephosphorylates glycogen phosphorylase, inactivating it and stopping the release of glucose from glycogen breakdown.
Protein phosphatase 1 (PP1).
_______________ are common structural motifs in signaling proteins.
SH2 domains.
SH2 domains bind specifically but reversibly to phosphorylated _____________ residues.
Tyrosine.
________________ and _______________ are involved in inflammation response and are activated by cytokines.
JAK, STAT.
_________________ are family of kinases that respond to mitogens, growth factors and pro-inflammatory signals that lead to cell proliferation. Contribute to the unmitigated growth of cells in cancer.
Mitogen-activated protein kinases (MAP).
___________________ receptors bind to lipoplysacharrides, endotoxins, fibrillar and profilin (bacterial proteins), and several heat shock proteins.
Toll-like
__________________ small, serine-threonine protein kinases that regulate progression throughout the cell cycle. Regulate cell growth and replication.
Cyclin-dependant kinases (CDK)
_______________ is a gaseous signaling molecule that is involved in the nervous system.
Nitric Oxide
______________ is the process by which proteins are packaged, are sorted, and find their place in the cell.
Protein Trafficking
_______________ is a short peptide sequence that belong to proteins that move to a location outside the cytosol. Directs the nascent protein to an organelle.
Signal Sequence
_________________ is a protease that resides in the ER lumen. It cleaves the signal peptide of some proteins, resulting in the loss of the transmembrane domain and formation of a soluble protein within the ER lumen.
Signal Peptidase
Most proteins are packaged into membrane-bound transport ____________ for trafficking around the cell.
Vesicles
_______________ involves in vesicle formation, examples include clathrin, COPI, and COPII.
Coat Proteins
_______________ transport, trafficking of proteins out of the cell.
Anterograde
________________ transport, movement from the Golgi apparatus back to the ER.
Retrograde transport.
_________________ one of the main coat proteins found trafficking among the trans Golgi apparatus, the plasma membrane, and endosomal compartments. Involved in receptor-mediated endocytosis of lipoproteins.
Clathrin
_______________ coat proteins undergo retrograde transport.
COPI
_______________ coat proteins undergo anterograde transport.
COPII
_______________ can occur via the fusion of a vesicle of neurotransmitter or integral membrane proteins with the plasma membrane.
Vesicular fusion
Vesicular fusion triggers the ____________ of the vesicle contents, either into the target membrane or outside the cell in the form of secretion.
Exocytosis.
_______________ -snare bind to vesicles.
V
_____________ -snare bind to the target membrane.
T
_______________ are integral membrane proteins, anchored in their C termini.
SNARE structure
