Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
List the 3 general mechanisms by which molecules enter the cell |
Diffusion, protein-mediated transport, endocytosis/exocytosis |
|
|
What is Henderson-Hasselbach's Equation? |
log [HA/A-] = pKa-pH |
|
|
What are two types of ATP-driven pumps? |
ATP-driven ion pumps, ABC transporters |
|
|
What is the role of an ABC transporter? |
These ATP-driven pumps specialize in moving small compounds (drugs/toxins) out of cells |
|
|
What are the two types of active transporters? |
ATP-driven ion pumps, ABC transporters |
|
|
Name three ways in which ion channels can be gated |
Mechanically-gated, ligand-gated, and voltage-gated |
|
|
What are the five types of signaling? |
Endocrine, paracrine, autocrine, juxtacrine, and neuronal signaling |
|
|
Name four classes of signal receptors |
Nuclear receptor (intracellular receptor) Enzyme-coupled receptor (cell-surface receptor) Ligand-gated ion channels (cell-surface receptor) G-protein-coupled receptor (cell-surface receptor) |
|
|
Name two points in G-protein-mediated signaling pathway at which signal is amplified |
Activated receptors can activate multiple g-proteins Activated G-proteins can activate many second messengers until they are turned off |
|
|
What is the mechanism of the Gs-mediated signaling pathway? |
Gs activates adenylyl cyclase, which converts ATP to cAMP. [cAMP] increases and activates PKA |
|
|
What is the mechanism of the Gi-mediated signaling pathway? |
Gi inhibits adenylyl cylcase, decreasing [cAMP] |
|
|
What is the mechanism of the Gq-mediated signaling pathway? |
Alpha(q) activates phospholipase C (PLC), which cleaves PIP2 in the plasma membrane. This forms DAG and IP3. IP3 diffuses and binds to ER to release calcium ions into the cytosol. DAG remains embedded in the plasma membrane and activates PKC. |
|
|
How do calmodulin and myosin light chain kinase (MLCK) regulate smooth muscle contraction? |
When calcium ion concentration increases, calcium ions bind to calmodulin and activate it. Calmodulin de-phosphorylates MLCK, activating it. Active MLCK can then phosphorylate and activate myosin light chains (MLC), which triggers contractions |
|
|
How does the Gs-mediated pathway mediate smooth muscle relaxation? |
Gs-mediated pathway activates protein kinase A (PKA), which phosphorylates and deactivates MLCK. MLCK can no longer activate MLC, prompting muscle relaxation |
|
|
What materials do smooth muscle cells secrete? |
Collagen, elastin, and proteoglycan |
