Physiology Concepts Quiz

Physiology Concepts Quiz

Created by
@ARenee

Questions and Answers

Which component of the cell membrane is responsible for linking with another molecule, such as choline or ethanolamine?

Phosphate head

What is the usual length of the fatty acid tail in the glycerophospholipids of the cell membrane?

16-18 carbons

Which type of membrane protein is involved in identifying foreign substances and initiating an immune response?

Receptor protein

Which cellular structure is primarily responsible for maintaining cell shape and providing mechanical support?

<p>Intermediate filaments</p> Signup and view all the answers

Which lipid component of the cell membrane is important for stabilizing membrane fluidity and integrity?

<p>Cholesterol</p> Signup and view all the answers

Which cytoskeletal component is involved in intracellular transport, aiding in vesicle movement within the cell?

<p>Microtubules</p> Signup and view all the answers

Which function of the cell membrane involves regulating the passage of molecules into and out of the cell?

<p>Transport</p> Signup and view all the answers

Why are cell membranes considered semi-permeable?

<p>Because they allow the passage of water but prevent the passage of many solutes.</p> Signup and view all the answers

What is the role of aquaporins in the plasma membrane?

<p>Enhancing high water conductance.</p> Signup and view all the answers

How does the Na+/K+ ATPase prevent cell swelling?

<p>By establishing a gradient of sodium and potassium across the membrane.</p> Signup and view all the answers

What happens when ATP levels fall to 10% of normal levels in cells?

<p>Cells start to swell.</p> Signup and view all the answers

What do cell membranes rely on for important signaling and metabolic functions?

<p>Concentration gradients.</p> Signup and view all the answers

What is the primary function of the Na+/K+ ATPase transporter?

<p>To regulate solute concentration and cell volume.</p> Signup and view all the answers

Why is the plasma membrane impermeable to many solutes, especially larger ones?

<p>Because large solutes cannot pass through the aquaporins due to their size.</p> Signup and view all the answers

What type of process involves a protein moving a substance(s) across a membrane against a concentration gradient using ATP?

<p>Active transport</p> Signup and view all the answers

Which protein allows a substance to move across the membrane along its concentration gradient?

<p>Aquaporins</p> Signup and view all the answers

What is the primary driving force that moves Na+ into the cell according to the text?

<p>High [Na+] in the extracellular fluid</p> Signup and view all the answers

Which type of transport involves a protein carrier binding to a substance and transporting it across a membrane along its concentration gradient?

<p>Facilitated transport</p> Signup and view all the answers

What is the process called that transports two substances (X and Y) using the same protein?

<p>Cotransport</p> Signup and view all the answers

Which of the following proteins moves substances across the membrane against their concentration gradients?

<p>Na+/K+ ATPase</p> Signup and view all the answers

What type of transport involves a protein forming a channel that allows substances to move across the membrane along their concentration gradients?

<p>Passive transport</p> Signup and view all the answers

What is the main function of most receptors on the cell membrane, according to the text?

<p>Binding to extracellular signals</p> Signup and view all the answers

Which part of the receptor plays a role in amplifying the signal, as mentioned in the text?

<p>Intracellular domain</p> Signup and view all the answers

How does the cell decide whether to respond to a signal such as a hormone, according to the text?

<p>By expressing the specific receptor</p> Signup and view all the answers

Which type of proteins are mentioned in the text to have diverse functions like signaling and transport?

<p>Membrane proteins</p> Signup and view all the answers

In extracellular signaling, what is typically required for a cell to respond to a signal?

<p>Expressing the specific receptor for the signal</p> Signup and view all the answers

Which domain of the receptor extends through the lipid bilayer, as mentioned in the text?

<p>Hydrophobic domain</p> Signup and view all the answers

What is the primary role of hydrophobic domains in most cell membrane receptors?

<p>Extending through the lipid bilayer</p> Signup and view all the answers

What determines whether a cell responds to a growth factor or anti-growth signal?

<p>Expression of specific receptor</p> Signup and view all the answers

Which part of a typical extracellular signal plays a critical role in determining if a cell will respond?

<p>Specific receptor expression</p> Signup and view all the answers

What is the role of flippase in the translocation of phospholipids across the ER membrane?

<p>Translocates phospholipids from the cytosolic side to the luminal side</p> Signup and view all the answers

What component is necessary to help with the addition of head groups to phosphatidic acid?

<p>Adenine</p> Signup and view all the answers

Why can't newly made phospholipids spontaneously flip over to the luminal side of the ER membrane?

<p>Because of the presence of specific enzymes</p> Signup and view all the answers

What happens to pieces of sER membrane containing new phospholipids?

<p>They bud off as vesicles and are inserted into the plasma membrane</p> Signup and view all the answers

Which side of the ER membrane do flippases translocate phospholipids to?

<p>Cytosolic side</p> Signup and view all the answers

In the context of phospholipid translocation, what is the function of flippase?

<p>Translocates lipids between membrane leaflets</p> Signup and view all the answers

What is a key characteristic of the translocation process facilitated by flippase?

<p>Specific directionality in lipid movement</p> Signup and view all the answers

What role do vesicles play in the transportation of new phospholipids?

<p>They insert new phospholipids into the plasma membrane</p> Signup and view all the answers

What are the three main components of a phospholipid?

<p>Hydrocarbon chain, Backbone, and Glycerol</p> Signup and view all the answers

Which derivative is formed when both fatty acids are linked to the glycerol backbone with an ester link in a phospholipid?

<p>Phosphatidate</p> Signup and view all the answers

Why is phosphatidic acid referred to as a 'phosphate-alcohol head group'?

<p>It has a phosphate group and an alcohol group in its structure</p> Signup and view all the answers

Which component forms the backbone of sphingomyelin?

<p>Ceramide</p> Signup and view all the answers

What is the basic structure of a phospholipid?

<p>Phosphatidate H</p> Signup and view all the answers

Which are the three most common phosphoglycerides found in the cell membrane?

<p>Phosphatidylethanolamine, Phosphatidylserine, Phosphatidylcholine</p> Signup and view all the answers

What is formed when one fatty acid is linked to the glycerol backbone with an ester link and the other with an ether link?

<p>Plasmalogen</p> Signup and view all the answers

Which type of phospholipid is much more common in the cell membrane?

<p>Phosphatidates</p> Signup and view all the answers

What is the first step in phospholipid synthesis as described in the text?

<p>Addition of two fatty acyl CoAs to glycerol-3-phosphate</p> Signup and view all the answers

What is the common feature regarding the fatty acids attached at carbon positions 1 and 2 in phosphatidic acid?

<p>C-1 is saturated and C-2 is unsaturated</p> Signup and view all the answers

What occurs during step 3 of phospholipid synthesis?

<p>Activation of a hydroxyl group by attachment of cytosine diphosphate (CDP)</p> Signup and view all the answers

Which molecule is responsible for donating methyl groups in the conversion of phosphatidylethanolamine to phosphatidylcholine?

<p>S-adenosylmethionine (SAM)</p> Signup and view all the answers

What role does phosphatidylinositol primarily play in cell membranes according to the text?

<p>Cell signaling</p> Signup and view all the answers

Which type of phospholipid interconversion can occur in a reversible head-group exchange reaction?

<p>Phosphatidylserine to phosphatidylethanolamine</p> Signup and view all the answers

What happens when a eukaryotic cell adds CDP-headgroup to diacylglycerol during phospholipid synthesis?

<p>Addition of a head group to the diacylglycerol</p> Signup and view all the answers

'Methyl groups are donated by S-adenosylmethionine (SAM)' - Which process does this statement refer to?

<p>&quot;Addition of 3 methyl groups&quot;</p> Signup and view all the answers

Where does phospholipid synthesis primarily occur?

<p>Smooth ER</p> Signup and view all the answers

What is the first shared step between phospholipid synthesis and triacylglycerol synthesis?

<p>Synthesis of glycerol backbone</p> Signup and view all the answers

What molecule can glycerol-3-phosphate be derived from?

<p>Dihydroxyacetone phosphate (DHAP)</p> Signup and view all the answers

Which cellular structure is involved in the conversion of glycerol-3-phosphate from dihydroxyacetone phosphate (DHAP)?

<p>Mitochondria</p> Signup and view all the answers

What is the final step in phospholipid synthesis after the addition of the head group?

<p>Exchange/modification of head group</p> Signup and view all the answers

Which type of phospholipid is synthesized with ceramide backbone instead of glycerol?

<p>Sphingomyelin</p> Signup and view all the answers

What is the primary function of attachment of fatty acids to the glycerol backbone in phospholipid synthesis?

<p>Facilitate transport across membranes</p> Signup and view all the answers

Which cellular compartment is responsible for the initial steps of phospholipid synthesis?

<p>Endoplasmic reticulum</p> Signup and view all the answers

What is the step in phospholipid synthesis that differentiates it from triacylglycerol synthesis?

<p>Exchange/modification of head group</p> Signup and view all the answers

What happens to glycerophospholipids after the addition of head groups?

<p>They undergo exchange or modification.</p> Signup and view all the answers

What is the cellular location where cholesterol synthesis primarily occurs?

<p>Endoplasmic reticulum</p> Signup and view all the answers

Which organs significantly contribute to cholesterol synthesis within the body?

<p>Liver and kidney</p> Signup and view all the answers

What is the key regulatory enzyme involved in cholesterol synthesis?

<p>HMG CoA reductase</p> Signup and view all the answers

What is the main influence on HMG CoA reductase by insulin and glucagon?

<p>Inhibition</p> Signup and view all the answers

Which lipid component is found in large amounts in the cell membrane along with phospholipids?

<p>Steroids</p> Signup and view all the answers

How many fused rings does cholesterol contain in its structure?

<p>Four</p> Signup and view all the answers

What molecular group characterizes sterols like cholesterol?

<p>Hydroxy group at C3</p> Signup and view all the answers

Which molecule is involved in the inhibition of HMG CoA reductase by high intracellular levels of cholesterol?

<p>Cholesterol esters</p> Signup and view all the answers

How many acetyl CoA molecules are required to form squalene in cholesterol synthesis?

<p>3</p> Signup and view all the answers

Which enzyme catalyzes the rate-limiting step in the formation of Mevalonate?

<p>HMG CoA reductase</p> Signup and view all the answers

What is the intermediate compound formed by the condensation of 6 activated isoprene units?

<p>Squalene</p> Signup and view all the answers

Which step in cholesterol synthesis involves the conversion of mevalonate into activated isoprenes?

<p>Step 2</p> Signup and view all the answers

The cyclization of squalene into cholesterol occurs in which step of cholesterol synthesis?

<p>Step 4</p> Signup and view all the answers

What is the highly-regulated enzyme catalyzing the rate-limiting step of cholesterol synthesis?

<p>HMG CoA reductase</p> Signup and view all the answers

Which cellular organelle hosts HMG-CoA reductase, the main regulatory enzyme in cholesterol synthesis?

<p>Smooth endoplasmic reticulum</p> Signup and view all the answers

What inhibits HMG-CoA reductase by promoting its phosphorylation, thus inhibiting cholesterol synthesis?

<p>Glucagon</p> Signup and view all the answers

Which condition leads to the blockage of transcription of the HMG-CoA reductase gene?

<p>High intracellular cholesterol levels</p> Signup and view all the answers

How does insulin affect HMG-CoA reductase activity?

<p>Promotes de-phosphorylation, activating the enzyme</p> Signup and view all the answers

What happens to HMG-CoA reductase when it is in its inactive phosphorylated state?

<p>It tends to remain inactive</p> Signup and view all the answers

How does high intracellular cholesterol levels affect esterification of cholesterol?

<p>Promotes esterification for storage in the cell</p> Signup and view all the answers

What is the driving force for the flow of a substance from point A to point B in a system?

<p>Energy gradient between point A and point B</p> Signup and view all the answers

How is flow related to the size of the energy gradient between two points in a system?

<p>Flow is directly related to the gradient size</p> Signup and view all the answers

What type of law describes fluid flow in a system?

<p>Poiseuille's law</p> Signup and view all the answers

Which factor directly influences the amount of flow from point A to point B in a system?

<p>Energy gradient between A and B</p> Signup and view all the answers

What does every system have that resists the flow of a substance from one point to another?

<p>Factors</p> Signup and view all the answers

In the model of flow down gradients, what does point A represent?

<p>Starting point</p> Signup and view all the answers

What does Poiseuille's law describe in the context of a system?

<p>Fluid flow</p> Signup and view all the answers

What parameter causes gas or liquid to flow from point A to B in a tube?

<p>Hydrostatic pressure</p> Signup and view all the answers

Which law determines the rate of flow of a gas or liquid through a tube?

<p>Pouiseuille's law</p> Signup and view all the answers

What characteristics of the substance impacts its flow in a tube according to the text?

<p>Viscosity of the fluid</p> Signup and view all the answers

What does Poiseuille's law define in the context of fluid flow through a tube?

<p>Volume of liquid passing through a tube per unit time</p> Signup and view all the answers

Which process can drive the molecular flow of gases, water, and solutes as described in the text?

<p>All of the above</p> Signup and view all the answers

What major variable is determined by Fick's law and Ohm's law in relation to the movement of substances in the body?

<p>Rate of diffusion</p> Signup and view all the answers

What characteristics determine the movement of gases and fluids through vessels?

<p>Physical and chemical properties of the gases and fluids</p> Signup and view all the answers

What critical impact does physical structure have on the flow of substances in a tube?

<p>Resistance to flow</p> Signup and view all the answers

What does the Nernst equation primarily indicate?

<p>Energy gradient for particle movement</p> Signup and view all the answers

Why is the Nernst potential important in understanding ion movement across a membrane?

<p>It influences the energy gradient for ion movement</p> Signup and view all the answers

What aspect does the Nernst potential NOT account for when describing ion movement?

<p>Current flow or resistance of the membrane</p> Signup and view all the answers

In the context of Nernst potential, what does the negative voltage value signify?

<p>Anions moving out of the cell</p> Signup and view all the answers

Which factor determines whether sodium or potassium has an unequal distribution across the cell membrane?

<p>Ratio of intracellular to extracellular concentrations</p> Signup and view all the answers

What is the significance of understanding the Nernst potential in relation to ion movement?

<p>Predicting ion movement direction based on voltage</p> Signup and view all the answers

Why is knowing the Nernst potential crucial for understanding cellular physiology?

<p>Balancing electrochemical gradients for ion transport</p> Signup and view all the answers

What aspect of Robert’s medical history explains his foot swelling?

<p>Decreased cardiac output and worsening blood supply</p> Signup and view all the answers

What is the main cause of Robert's shortness of breath?

<p>Decreased cardiac output</p> Signup and view all the answers

How does Robert's foot swelling illustrate the physicochemical laws discussed in the pre-learning and lecture?

<p>Starling's Law of Capillary Forces</p> Signup and view all the answers

Why does blood 'back up' in the venous system in heart failure?

<p>Worsened cardiac output from the ventricles</p> Signup and view all the answers

Which condition primarily leads to impaired 'forward-flow' in heart failure patients?

<p>Decreased cardiac output</p> Signup and view all the answers

What happens to tissues with poor blood supply in heart failure?

<p>They experience enhanced function</p> Signup and view all the answers

How does the physiopathology of heart failure manifest physicochemical principles?

<p>'Starling's Law of Capillary Forces' impacts fluid distribution</p> Signup and view all the answers

Why does a neuron maintain a membrane potential close to the Nernst potential for potassium?

<p>To ensure efficient signaling through action potentials</p> Signup and view all the answers

What purpose does the unequal distribution of charge serve in living cells?

<p>To regulate the transport of substances</p> Signup and view all the answers

What role do selective transporters and channels play in establishing the membrane potential of living cells?

<p>They facilitate the movement of specific ions to create an imbalance</p> Signup and view all the answers

How do medications and pathologies impact the membrane potential of cells?

<p>They can alter the membrane potential of different cell types</p> Signup and view all the answers

Why doesn't a neuron's membrane potential match exactly with the equilibrium Nernst potential for potassium?

<p>The potential difference is necessary for resting state function</p> Signup and view all the answers

What is the significance of living cells always having a membrane potential?

<p>It maintains a stable environment for cellular processes</p> Signup and view all the answers

In what way does an unequal distribution of charge aid cellular signaling?

<p>By facilitating specific ion movements for signaling</p> Signup and view all the answers

Which equation predicts the membrane potential when it is permeable to more than one substance?

<p>Goldman Field equation</p> Signup and view all the answers

In the Goldman Field equation for membrane potential, what does 'V𝑚' represent?

<p>Membrane potential</p> Signup and view all the answers

What does the term '𝑝𝐾' represent in the Goldman Field equation?

<p>Permeability to potassium</p> Signup and view all the answers

Mary, a patient presenting with numbness in her feet, has a history of which type of diabetes?

<p>Type 2 diabetes mellitus</p> Signup and view all the answers

In the context of Mary's condition, what physiological concept relates to the slow progressive numbness in her feet?

<p>Membrane potential changes</p> Signup and view all the answers

Which substance's permeability is NOT considered in the Goldman Field equation for membrane potential?

<p>Sodium (Na+)</p> Signup and view all the answers

What is the primary role of membrane permeability in determining membrane potential according to the Goldman Field equation?

<p>Regulating ion flow across the membrane</p> Signup and view all the answers

What symptoms might be associated with changes in membrane potential due to alterations in ion permeabilities as per the Goldman Field equation?

<p>Muscle weakness or paralysis</p> Signup and view all the answers

Which is NOT a factor influencing Mary's slowly progressive numbness according to the text?

<p>Adequate sleep patterns</p> Signup and view all the answers

What physiological process serves as a foundation for understanding gradual numbness and coldness in Mary's feet?

<p>Membrane potential changes</p> Signup and view all the answers

What is the concentration of Ca+2 in the cytosol of a 'resting' cell?

<p>0.1 micromolar</p> Signup and view all the answers

How many Ca+2 ions does each calmodulin bind to before becoming activated?

<p>Four</p> Signup and view all the answers

What activates the release of Ca+2 from the endoplasmic reticulum?

<p>IP3</p> Signup and view all the answers

What lipid-soluble molecule stays within the cell membrane and diffuses throughout it?

<p>DAG</p> Signup and view all the answers

What do both Ca+2 and DAG work together to activate?

<p>PK C</p> Signup and view all the answers

Why is there a high concentration gradient for Ca+2 from the ER into the cytosol?

<p>To allow Ca+2 to enter the cytosol</p> Signup and view all the answers

What happens when the concentration of Ca+2 increases in the cytosol?

<p>Calmodulin binds to effectors</p> Signup and view all the answers

What is the purpose of calmodulin once it is activated?

<p>To activate PK C</p> Signup and view all the answers

What is the role of Gi GPCR in cell signaling?

<p>Downregulates the activity of Gs</p> Signup and view all the answers

What is the impact of opening a channel that allows sodium to enter the cell on its membrane potential?

<p>Depolarization</p> Signup and view all the answers

What is the significance of -90 mV being the Nernst potential for K+?

<p>It tends to cause most cells to be 'less' activated</p> Signup and view all the answers

What would happen to the cytosolic calcium concentration if a channel allowing calcium entry was opened?

<p>Increase</p> Signup and view all the answers

How does the activity of Na+/K+-ATPase contribute to the cell's membrane potential?

<p>Creates an inside-negative membrane potential</p> Signup and view all the answers

Why does sodium want to diffuse into the cell when a channel for sodium opens?

<p>Due to a low cytosolic concentration of sodium inside the cell</p> Signup and view all the answers

How does opening a channel for sodium impact the membrane potential?

<p>Causes depolarization</p> Signup and view all the answers

What is the purpose of PK C modulating the activity of many other effectors?

<p>Modulates cellular responses by affecting other effectors</p> Signup and view all the answers

What is the key function of receptors in the cell membrane as mentioned in the text?

<p>Transducing extracellular signals into intracellular signals</p> Signup and view all the answers

In the context of intracellular signaling models, what is the role of the first messenger?

<p>Binds to and activates cell membrane receptors</p> Signup and view all the answers

Which event characterizes an active intracellular signaling system according to the model presented in the text?

<p>Extracellular signal triggers the activation of second messengers</p> Signup and view all the answers

What is the main function of G-proteins in intracellular signaling as described in the text?

<p>Amplify the signal by activating effector proteins</p> Signup and view all the answers

What term best describes the process where cells reduce their response to repeated or continuous stimulation?

<p>Desensitization</p> Signup and view all the answers

Which statement accurately represents the role of lipid molecules in intracellular signaling?

<p>Lipids contribute to signaling by regulating membrane properties and localizing proteins</p> Signup and view all the answers

What is a key function of second messengers in intracellular signaling pathways?

<p>Amplify and relay signals from cell surface receptors to effector proteins</p> Signup and view all the answers

Why are receptors on the cell membrane considered essential components of cellular signaling pathways?

<p>To transduce extracellular signals into intracellular signals for cellular responses</p> Signup and view all the answers

What is a key limitation of the model described in the text?

<p>It oversimplifies the signaling events</p> Signup and view all the answers

What is the main purpose of the model for categorizing steps in signaling events?

<p>To offer a quick overview of similarities and differences</p> Signup and view all the answers

What role does negative feedback play in the model?

<p>Degradation of 2nd messengers</p> Signup and view all the answers

What does the G-Protein-Coupled Receptors (GPCR) refer to in the text?

<p>A type of membrane receptor</p> Signup and view all the answers

What aspect of the model helps in understanding complex signaling events?

<p>Categorization of steps</p> Signup and view all the answers

What is a caveat mentioned regarding the accuracy of the model?

<p>&quot;It is not perfectly accurate&quot;</p> Signup and view all the answers

How does the model help in understanding different biological strategies according to the text?

<p>&quot;By providing quick comparisons&quot;</p> Signup and view all the answers

What is the main characteristic of receptor tyrosine kinases?

<p>Intrinsic kinase activity</p> Signup and view all the answers

How does the binding of a ligand affect receptor tyrosine kinases?

<p>Dimerizes the receptor</p> Signup and view all the answers

Which type of molecules can act as ligands for receptor tyrosine kinases?

<p>Growth factors</p> Signup and view all the answers

What is the role of phosphorylation in activating receptor tyrosine kinases?

<p>Activates the receptor's kinase activity</p> Signup and view all the answers

Which signaling cascade is commonly associated with receptor tyrosine kinases?

<p>Ras cascade</p> Signup and view all the answers

What is the role of Ras in the RTK → Ras → MAP K cascade pathway?

<p>It activates Raf, another small plasma membrane-associated G-protein</p> Signup and view all the answers

Which molecule is Ras known to directly interact with to initiate its activation in the cell?

<p>RTK</p> Signup and view all the answers

What is the key signaling mechanism mentioned in the text that is unique to insulin signaling and involves PI3K?

<p>Akt system</p> Signup and view all the answers

Which pathway is most commonly associated with Receptor Tyrosine Kinase (RTK) activation according to the text?

<p>Ras-Raf-MAP kinase pathway</p> Signup and view all the answers

What is the mechanism by which Ras inactivates itself within the cell?

<p>Cleaving GTP into GDP</p> Signup and view all the answers

What is the final outcome of the RTK → Ras → MAP K cascade pathway?

<p>Phosphorylation of transcription factors</p> Signup and view all the answers

Which signaling pathway does Ras primarily contribute to within the cell?

<p>Ras-Raf-MAP kinase pathway</p> Signup and view all the answers

What is the main role of PIP3 in the cellular signaling pathway described in the text?

<p>Bringing PDK1 and Akt together at the membrane</p> Signup and view all the answers

How is nitric oxide (NO) unique compared to other second messengers mentioned in the text?

<p>It is rapidly degraded</p> Signup and view all the answers

What activates PDK1 in the cellular signaling pathway described in the text?

<p>PIP3</p> Signup and view all the answers

In the PI3K-Akt signaling pathway, what is the main function of Akt?

<p>Influencing a range of intracellular targets</p> Signup and view all the answers

What is the primary source of nitric oxide (NO) production in cells?

<p>NOs acting on L-arginine</p> Signup and view all the answers

Which kinase is activated by phosphorylation from PDK1 in the cellular signaling pathway discussed in the text?

<p>Akt</p> Signup and view all the answers

What is the major effect of nitric oxide (NO) on smooth muscle?

<p>Relaxation</p> Signup and view all the answers

Which enzyme converts PIP2 into IP3 and DAG in the cell membrane?

<p>PLC</p> Signup and view all the answers

What brings PDK1 and Akt together at the membrane in the cellular signaling pathway?

<p>PIP3</p> Signup and view all the answers

What is a key feature of nitric oxide (NO) that allows it to diffuse across cell membranes quickly?

<p>Being hydrophobic</p> Signup and view all the answers

Which model involves pathways related to regulated proteolysis?

<p>Model 3</p> Signup and view all the answers

Which model directly involves non-coding RNA affecting transcription?

<p>Model 5</p> Signup and view all the answers

Which model includes intracellular receptors like Steroid and Thyroid hormones?

<p>Model 4</p> Signup and view all the answers

Which model represents pathways involving activation of transcription factors?

<p>Model 2</p> Signup and view all the answers

In the discussed models, which one specifically involves cAMP activating PKA?

<p>Model 1</p> Signup and view all the answers

Which model does NOT involve altered protein synthesis?

<p>Model 3</p> Signup and view all the answers

Which model is associated with a slower signaling process due to gene transcription?

<p>Model 5</p> Signup and view all the answers

Which model involves the AKT pathway activated by PI 3 Kinase?

<p>Model 1</p> Signup and view all the answers

How can intracellular signaling cascades affect transcription?

<p>By affecting transcription factors</p> Signup and view all the answers

What is the role of co-activators and co-repressors in transcription regulation?

<p>They bind to transcription factors to influence transcription</p> Signup and view all the answers

In the context of signaling cascades, which component binds to a transcription factor to modify gene transcription?

<p>Protein kinase</p> Signup and view all the answers

What is the effect of an inhibitory enzyme in a signaling cascade model?

<p>Shuts off the signaling cascade</p> Signup and view all the answers

Which molecule is responsible for dissociating the catalytic and regulatory subunits of PKA?

<p>cAMP</p> Signup and view all the answers

What is the primary function of cAMP in a signaling cascade?

<p>Activates cAMP-dependent protein kinase</p> Signup and view all the answers

How does cAMP affect the structure of PKA?

<p>Causes binding of catalytic and regulatory subunits</p> Signup and view all the answers

In a signaling cascade, what is the direct consequence of an increase in cytosolic cAMP concentration?

<p>Activation of cAMP-dependent protein kinase</p> Signup and view all the answers

How does CaM-Kinase affect gene transcription?

<p>Activates transcription of genes with a CRE</p> Signup and view all the answers

What is the function of Protein Kinase C (PKC) when activated?

<p>Phosphorylates target proteins to activate/inhibit transcription factors</p> Signup and view all the answers

How is PKC activated?

<p>By phosphorylating target proteins</p> Signup and view all the answers

Which protein is activated by receptor tyrosine kinases in the pathway mentioned?

<p>Ras</p> Signup and view all the answers

What does Active Ras trigger in the pathway?

<p>Activation of MAP Kinase (Erk)</p> Signup and view all the answers

Where can MAP Kinase (Erk) function after being activated?

<p>Nucleus</p> Signup and view all the answers

What immediate effect does the activation of MAP Kinase (Erk) have on gene expression?

<p>Activates transcription factors for immediate early genes</p> Signup and view all the answers

What is the primary role of PKC in the pathway described?

<p>Phosphorylate target proteins to regulate gene transcription</p> Signup and view all the answers

How does cAMP activate PKA in the context of transcription regulation?

<p>By phosphorylating specific target proteins in the cytoplasm</p> Signup and view all the answers

What is the role of CREB in transcription regulation?

<p>Stimulates the transcription of genes with a CRE</p> Signup and view all the answers

How does CaM Kinase (CaMKinase) affect transcription regulators?

<p>Phosphorylates transcription regulators to increase or decrease transcription</p> Signup and view all the answers

What is the function of a co-activator like CREB-binding protein (CBP) in gene transcription?

<p>Promotes transcription by interacting with activated CREB</p> Signup and view all the answers

Which enzyme inactivates cAMP to shut off the signal transduction pathway?

<p>Phosphodiesterase</p> Signup and view all the answers

How does PKA affect transcription factors as mentioned in the text?

<p>Enters the nucleus and activates CREB</p> Signup and view all the answers

What is the function of activated CREB in transcription regulation?

<p>Promotes gene transcription by phosphorylating target proteins</p> Signup and view all the answers

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