steps of signal transduction quizlet


What type of molecules can diffuse through the plasma membrane and bind to intracellular receptors, A(n) is an example of a signal molecule that can bind to an intracellular receptor and thereby cause a gene to be turned on or off, Steroids bind to intracellular receptors, which can then bind to, and regulate the.

which response? Explain each choice with a short sentence, (a) temperature highs and lows (b) precipitation (c) hours of sunshine (d) wind speed (e) humidity. What is the general process of the cell signalling pathway? Critical as a mechanism in biology - cellular singling helps maintain homeostasis (balance) e.g. Describe how activation of certain receptor tyrosine kinases can lead to the activation of the small G-protein Ras. Failure of this signal transduction process leads to diseases such as syndactyly. (a) light bulbs (b) a refrigerator (c) a car. Because of other elements of specificity of cell signalling and coordination of the response, Discuss different tissue types relating to commonalities, The same second messenger can occur in many tissues and cells e.g. Upon opening, it allows _____________ to go through. What are the types of structural proteins? How and what do hormones and other extracellular signals initiate? The main way insulin does this is by binding to the insulin receptor, which signals throughout the cell to produce more glucose transporters to bring glucose into the cell. Where will an endocrine hormone be released from and to? _______________ receptors that ______________ _____________ and __________ up when a _______________ binds to it. Insulin travels through your blood telling all of your cells along the way to open up for sugar. Because of this, we refer to other non-protein molecules utilized to carry a signal as ________________ _______________, Two examples of non-protein molecules that sends the signal to initiate a cellular response are __________ __________ and _________ _______. Describe the characteristics of a G-protein coupled receptor and explain what happens to the associated heterotrimeric G-protein when a G-protein coupled receptor binds its ligand. signal is passed on through multiple molecular interactions to reach its intracellular target. As a result, Ca2+ ions flow out of the ER and into the cytosol. MC4R is activated by endogenous ligand alpha-melanocyte-stimulating hormone (a-MSH) and once activated, what does MC4R couples to and activates? ventolin (salbutamol) - this mimics adrenaline at the beta2- adrenoceptor to treat asthma. Given that all species of life have evolved for the same amount of time since their common origin, how would you respond to someone who characterizes prokaryotes as primitive? In addition, name the two second messengers that are produced in the pathway and their functions in the cell. The fourth step of signal transduction is the activation of effectors that directly alter the physiological response. When cells divide, each daughter cell receives what. Describe the properties of a receptor tyrosine kinase (RTK), A transmembrane receptor protein that, when bound to the appropriate signal molecule, displays intracellular protein kinase activity, phosphorylating proteins at tyrosine residues. By binding to DNA it triggers the transcription of a specific gene. What receptor molecule would allow Na+ to flow into the cell? Why can common second messengers create different responses? Chemical signals that are not embedded in the membrane and can diffuse in the cell to pass on the message; they are intracellular molecules that change in concentration in response to environmental signals. The type of second messengers involved in the signal transduction pathway; the types of relay molecules within the cell; the enzyme that is activated by the G protein associated with the receptor; the cell type i n which the histamine receptor is located. Model 2: Steps 3, 4, and 5 are amplification steps. Different molecules are involved at each stage of cell signalling - which molecules are involved in reception? Which is a qualitative observation she may have made? What can second messenger molecules that are produced following receptor activation do? the cell-surface receptors for antigens or cytoplasmic receptors for steroid hormones, Discuss the 'lock and key' analogy of specific hormones binding to matched receptors, The "lock and key" analogy descries how each hormone has its own specific receptor; only when the hormone or ligand engages with the correct receptor, can it activate the receptor and trigger intracellular signalling leading to a response, Discuss drugs taking advantage of the "lock and key" mechanism to give highly specific medicines with few side effects, This is because they are only interacting with the target receptor and not other receptors; typical pharmaceuticals bind to the active site in place of the native substance and either block the endogenous molecule's signalling (bind but not identically, and then block, often referred to as antagonists) or mimic its effects (similar chemical structure, binds and triggers signalling in the same way) - e.g. Some important second messengers include cAMP, cGMP, calcium ion, IP3, and DAG. When the ligand (growth hormone) binds to the two receptors, they dimerize and the JAKs are brought into close proximity and can now phosphorylate each other. Is this property an advantage or a disadvantage for a soil additive? Insulin is released after an increase in blood sugar by cells in the pancreas. Protein phosphates dephosphorylate or remove phosphate groups from enzymes, including protein kinases, The process by which a signal is converted to a specific cellular response involves three stages, Reception of a signalling molecule; transduction of the signal; response to the signal. After a signaling process has been initiated and the information has been transduced to affect other cellular processes, the signaling process must be terminated. Pathway leads to a single response; pathway branches, leading to two responses; cross-talk occurs between two pathways; different receptor leads to a different response. Although there are thousands of receptors, there are relatively few, Multiple receptors can use common second messengers - second messengers are molecules (chemical signals) inside cells that act to, Transmit signals from a receptor to a target i.e. Smaller molecules called second messengers and protein phosphorylation by enzymes called protein kinases. Part of growth of an organism is controlling what cells need to die. Suggest why many globular proteins, in contrast to fibrous proteins, have a catalytic or regulatory role: If a farmers field has 75 earthworms per square meter, how many earthworms are in 4.5 square meters? IP3 diffuses through the cytosol and binds to an IP3-gated calcium channel in the ER membrane, causing it to open. cAMP because other aspects are tissue specific - there are 3 different tissue type examples, In tissue type 1, a hormone may try to bind to the tissue, but there is no receptor expressed in that tissue so, The hormone can't act - so the expression of the hormone is critical in whether or not the hormone will act, regardless of whether that tissue contains that particular second messenger, In tissue type 2, a hormone finds the receptor causing activation of receptor leading to production of second messenger (more second messenger as change in concentration - producing, Second target protein for second messenger leading to a response, In tissue type 3, a hormone binds to the receipt producing more second messenger, but, This particular tissue type expresses a different type of target protein. The release of a signalling molecule into the bloodstream to act upon a distant cell. Ca2+; cAMP; IP3, second messenger; adenylyl cyclase; phosphorylation cascade. What is the second of the three stages of cell signalling? In receptor tyrosine kinases, the receptor protein has a tyrosine kinase domain on the cytoplasmic portion of the protein. Genes are read in order to create proteins.

Cell signaling: This __________________ bonds to a specific protein ________________ which then results in a cellular ______________. What are the 2 mechanisms of transduction? The first step of signal transduction is the release of the primary messenger. The hormones passing through the membrane. What happens during the Transduction phase? If you don't produce insulin, your cells cannot take in the glucose and the cells start to die off. What are the steps of the mechanism of the histamine signal transduction pathway?

enzyme that catalyzes transfer of phosphate group from atp to another molecule, ligand binding to receptor protein is reversible, ligand differences in cytoplasmic and membrane receptors, cytoplasmic, membrane, ion channel, protein kinase, g protein-linked, acetylcholine allows Na to enter causing muscle contraction, alpha subunits of receptor bind the signal, Hormone signal binds to receptor, activating g protein, direct: receptor directly activates effector protein, intiating cell response, constant amplification, nucleus communication, specificity, variation in response, small, nonenzymatic molecules that mediate steps to amplify signal, signal transduction balance is achieved by, opening of ion channels, enzyme activity change (protein kinase), DNA transcription, allows small cells like 2nd messengers and hormones to pass between cells. What has the increased burden of obesity on the health sector prompted researchers to do? Proteins are not always the molecules to carry the signal in the transduction process. What is a widespread cellular mechanism for regulating protein activity? Cardiovascular drugs; diabetes drugs; migraine drugs; asthma drugs; anti-ulcer drugs; allergy drugs; etc. There are several categories of plasma membrane receptors including receptors that activate G proteins and receptors with protein kinase activity. What does the binding of signal molecules to tyrosine kinase receptors activate? phosphorylation of MAP kinase kinase kinase, etc.. mutant Ras (hyperactive form, cannot hydrolyze GTP) associated w/ 30% of human tumors. The activation of adenylate cyclase results in what? Receptors that a plasma membrane proteins. What does signal transduction often involve? Classify the following as either a weather observation for a specific location and day or an aspect of a locations climate. Steroids - they are non polar and can diffuse through the plasma membrane.

The Muesli-Mix is a popular breakfast hangout near a campus. The cholera bacterium Vibrio cholera produces an enzyme toxin that chemically modifies a G protein involved in regulating salt and water secretion in intestinal cells.

Be sure to describe the role of a guanosine exchange factor (GEF) and a GTPase activating protein (GAP) in Ras function. how does fructose enter glycolysis from the liver? As a result, Ca2+ ions flow out of the ER and into the cytosol, Provide an overview of transduction of the histamine signal, After the reception of the histamine signalling molecule, the active G protein activates the enzyme phospholipase C. Phospholipase C cleaves PIP2 into DAG and IP3. Enzymes help speed up chemical reactions in the body. At each step of amplification, the number of activated products is, At each step of amplification, the number of activated products is much greater than in the preceding step, this means, That only a very small amount of the initial hormone is needed and few receptors need to be activated to produced a response, Provide an example of the consequence of amplification, A single receptor has generated many second messenger molecule that can each go on and affect another molecule in the signalling cascade, Identify different physiological functions of cell surface receptors (response), The changes in chemicals results in activation or inhibition of proteins e.g. The half-life of carbon-14 is 5,730 years. Alternatively, even if the protein structure. In the absence of hormone, the JAKs are still associated with the monomeric receptor proteins. The process is called autophosphorylation; The phosphorylated tyrosine groups provide docking sites where relay proteins bind. Inactive receptor --> hormone binds to receptor --> receptor changes shape. which response? Seven-Transmembrane-Helix Receptors are critical to many physiological functions. Since the shape of the ligand and the receptor protein are compatible, the ligand will fit into the active site on the receptor protein.

Signal molecule --> receptor --> activated relate molecule --> phosphorylation cascade --> cellular response, What three amino acids are phosphorylated regarding the phosphorylaion cascade in signal transduction, Protein phosphates rapidly remove the phosphates from protein, this is. ribosomes that do not anchor to the RER surface during translation most probably. Different molecules are involved at each stage of cell signalling - which molecules are involved in transduction? A molecular switch, turning protein activity on and off or up and down as required. Give the general types of changes that can occur inside a cell as a result of the activation of a signal transduction pathway. Discuss transmitting messages across the cell membrane involving a conformational change in the receptor, Once that receptor of drug has bound to the receptor via lock and key mechanism, the crucial next step is how that drug or hormone can produce a response inside the cell without entering the cell - this happens via the sp-called conformational change - so transmitting messages across the cell membrane involves conformation/shape change sin the receptor. Signal molecules are usually not able to pass through the cell membrane or through transporters. Once a signal has been transmitted, what is the next step? What is the catalyst for alkene hydration?

Cascades of molecular interactions relaying signals from receptors to target molecules in the cell. MC4R plays an important role in the control of what? The basic effect of the cholera toxin is signal amplification, The effect of the toxin (regarding cholera) is to prevent the inactivation of the G protein, because, The modified G protein is unable to hydrolyse GTP to GDP , it remains stuck in its active form, continuously stimulating adenylyl cyclase to make cAMP. When activated, this enzyme converts _______ into ____________. The growth hormone receptor is somewhat similar to receptor tyrosine kinases, but differs in one way - the growth hormone receptors do not have tyrosine kinase domains. The store sells clothes. What does the chance of conformation convey regarding second messengers? What type of hormones bind to receptors located on the cell membranes? When histamine bonds to a histamine receptor, the specific cellular response that results is determined by the following factors: The type of histamine receptor; the type of cell in which the receptor is located; the enzyme that is activated by the G protein associated with the receptor; the types of second messengers involved in the final transduction pathway; the protein activated by the second messengers - signalling molecules can trigger a multitude of cellular responses, which may ultimately affect the transcript not genes, the activity of proteins, or cell growth and division, Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because, They amplify the original signal manyfold. Testosterone is an example of a chemical signal that affects the very cells that synthesise it, the neighbouring cells in the testis, along with distant cells outside the gonads. Amplification of cell and signal coordination and regulation. What is the conformational change process? Describe the fifth and final step of signal transduction. A sample is found to have 1/8 the original amount of carbon-14 in it. What is the "backbone" of macromolecules. Extracellular fluid - Reception (signalling molecule --> receptor) --> transduction ) --> relay molecules in a signal transduction pathway) response --> (activation of cellular response) - cytoplasm, Converting extracellular signals to specific responses inside the target cell. They usually are used to __________________ protein molecules in the transduction process. The IP3 signal transduction pathway is a good example of secondary messengers working on protein kinase C. These are, Give the definition of a kinase and explain the specific function of tyrosine kinases. A change in the amino acid sequence can alter what? Where does glycolysis occur in prokaryotes and eukaryotes? Transduction is that the signal simply moves through the cell unit, it reaches the location in which the response will occur, How the signal in model one was amplified, The signal in model 1 was amplified because one protein activated several relay proteins, which causes response, Responses that could occur due to a signal being received by a cell, Growth, Protein Manufacture, Enzyme Activation, What would need to occur to stop a response in the cell, The relay proteins would need to be deactivated (the ligand would need to decouple from the receptor), The ligand causes a receptor protein to activate a relay protein, Which steps in the phosphorylation cascade include phosphorylation, Where do the phosphate groups come from that are added to the proteins during phosphorylation, What class of enzymes perform phosphorylation, Steps in model 2 that represent reception, transduction, and response for the phosphorylation pathway, Reception: 1 - Ligand connects to the receptor protein, How does the cell respond to the signal received in model 2, A transcription factor activates (DNA transcription of a gene begins). Responses that the cell can have varies greatly. Adenylyl cyclase cAMP are not involved in the histamine signal transduction pathway. As a response, enzymes can become more or less active depending on how its new obtained shape from ligand bonding. (a) Why does calcium hydroxide raise soil pH? Regarding MC4R, the receptor is a seven-transmembrane G protein coupled receptor that is primarily expressed in what? DAG remains in the membrane where it activates protein kinase C; The activated protein kinase C phosphorylates other proteins causing responses of the cell; IP3 prompts the endoplasmic reticulum to cause release of Ca2+. A change in, insertion of or delete of a single nucleotide or a number of nucleotides in the DNA sequence will result in what? Obesity is a complex disorder that involves what factors? Monogenic obesity and can contribute to polygenic obesity. __________ _________ is a molecule made from _____. Protein kinases activate enzymes by phosphorylating or adding phosphate groups to them.

What protein molecule assists in the proper folding of other proteins, Triacylglycerols containing mainly saturated fatty acids. To act as a messenger, the cell receives a ________________ on an ion-gated channel receptor which _________ it up. Key decisions are made at the top and filter down through the organization. Cyclic adenosine monophosphate (cAMP), another common second messenger, is formed when adenylyl cyclase converts ATP to cAMP. Similarly, multiple pathways can facilitate the coordination of cellular responses to multiple signals. The message is then relayed through signal transduction, which may involve a phosphorylation cascade or second messengers such as cAMP, Ca2+ or IP3. Why is it not valid? The increase in the calcium ion concentration in the cytosol helps activate the cellular response; Signal transduction pathways that involve phosphorylation cascades or multiple second messengers, such as histamine's signal transduction pathway, enables a signal to be amplified and regulated at different points. The most common way of turning a protein "on" or "off" is through ___________________. What do phosphorylation and dephospho rylation events act like? A stimulus such as a wound or a digested meal triggers the release of the signal molecule, also called the primary messenger. Second messengers are small non-protein molecules that act as what? Secretory cell acts upon the adjacent target cell, Not a soluble singling molecule, rather is is attached to a cell and interacts with a receptor on a target cell leading to an effect, Provide an example of direct cell to cell signalling, T cell activation by proteins on the surface of antigen-presenting cells (common in the immune system). the histamine H1 receptor is a G protein-coupled receptor that activates phospholipase C in response to the binding of histamine - provide the process of histamine signal transduction from the H1 receptor, Enzyme cleaves PIP2, forming DAG and IP3 --> IP3 binds to a ligand-gated ion channel in the ER membrane --> calcium ions flow through the ligand-gated ion channel --> calcium ion concentration increases in the cytosol --> calcium ions activate a protein, leading to a cellular response, Both G protein-coupled receptors and receptor tyrosine kinases can initiate a pathway that uses the second messengers DAG and IP3 - in this pathway, reception of the signalling molecule leads to the activation of the enzyme phospholipase C. Phospholipase C cleaves a membrane phospholipid called PIP2 into DAG and IP3, Is a phospholipid in the plasma membrane that is cleaved to form two different second messengers, Is a second messenger formed, along with DAG, when a phospholipid in the membrane is cleaved, Is the second messenger formed, along with IP3, when a phospholipid in the membrane e is cleaved, Provide an overview of molecules involved in signal transduction pathways, Phospholipase C cleaves the membrane phospholipid PIP2, forming IP3 and DAG. More molecules than the original ligand are becoming involved, What advantage would there be to an organism if the signal transduction pathway had several amplification steps, A single ligand molecule(s) can lead to a magnified response by the cell, What would occur in the cell if the activated protein kinase continued to be active for a long period of time, What would need to occur in the cell to deactivate the protein kinase enzymes, Dephosphorylation and deactivation of the relay protein, Marie observed people at a store. G protein-coupled receptor; signalling molecule; receptor tyrosine kinase. They initiate a series of protein phosphorylations that lead to the response of the cell; Receptors with tyrosine kinase activity often bind hormones like insulin and other growth factors that affect cell growth ad differentiation, Nearly all body cells express receptors for epinephrine and norepinephrine, called adrenergic receptors. hormones; many medicines control cell singling events via receptors, Provide some examples of medicines that control cellular singling via G protein coupled receptors. which response? In the inactivated state, guanosine diphosphate (GDP) is bound to the G protein, Cyclic AMP is a second messenger - the first messenger is the hormone; Cyclic AMP activates the intracellular enzyme, protein kinase A, which can phosphorylate many other proteins; This second messenger system can also phosphorylate ion channels and alter their activity; The response of the cell ends when cAMP is degraded to AMP in a reaction catalysed by the enzyme phosphodiesterase; Amplification greatly increases the effect that a single molecule of a hormone can have on a cell; G proteins, that stimulate production of cAMP are known as Gs (s = stimulatory) proteins, Gi proteins (i = inhibitory) inhibit production of cAMP and the subsequent response of the cell; Another type of G protein activates an intracellular messenger system that uses diacylglycerol (DAG) and inositol triphosphate (IP3) as second messengers; DAG and IP3 function as second messengers. Explain. What do signal transduction pathways allow for? Specifically, if the mutation results in a change in amino acid that has different properties to the wild type amino acid (for example, a hydrophobic amino acid changes to a hydrophilic amino acid), this will change what? The binding of a signal molecule to a receptor initiates, Calcium ions that act as second messengers are stored in, catalyses the production of , which then opens an ion channel that releases into the cell's cytoplasm, Phospholipase C cleaves IP3 from a membrane protein, and IP3 then binds to a calcium channel on the, A protein kinase activating many other protein kinases is an example of, By activating many other molecules the initial signal is.