Signal Transduction Stimulus reaches receptor cellsReceptor protein is activatedCascade of second messengersIon channels open (or close)Change in membrane potential...

Sensory Reception $(29.1-29.3)$ Sensory receptors convert stimulus energy to action potentials. Sensory receptors are specialized cells that detect stimuli. Sensory transduction converts stimulus energy to receptor potentials, which trigger action potentials that are transmitted to the brain. Action potential frequency reflects stimulus strength.

Okay problem for as this, Which of the following is not membrane receptor eso? Let's go through each one individually. First, we'll start with channel linked, and I like to call these rather ion channels because ions cannot easily flow through the through the plasma membrane through the phosphor lipids. So there needs to be away for the ion exchange to occur in and out of the cell. So these ion channels normally take sodium or potassium and pump it in or out of the cell toe. Contain home eo static, solid concentration. And so, since this type of receptor is in the plasma membrane, it can't be applicable towards our response and going on down to enzymatic proteins. Enzymes do not usually flow into the cell. What happens is there is an enzyme in this external environment that bonds to the active site of the receptor, and then that triggers another and somatic reaction to occur within the cell again. There's no, um, there's no exchange. Nothing is happening. It's not coming through the plasma membrane and into the cell and triggering a reaction there. That is not happening. So we know that the answer is not enzymatic. G protein linked now G protein linked. Um, receptors are a little more complicated because what happens is there's an external stimuli that then triggers this, um, membrane receptor, which then sends a signal to the G protein toe where the G protein then acts and creates whatever product is desired. And these, uh, linked to the G proteins again. It comes through the plasma membrane. This right here is all one receptor. There's no transfer going straight through the plasma membrane, so we know that this is not our right answer. So then going down to D now a steroid reaction normally occurs when you have your steroid source on the outside of the cell. And what happens is that steroid comes into the cell and then continues on into the nucleus, where it then interacts with the crow Mattan to trigger the production of mRNA. And since this reaction is occurring within the cell within the nucleus and not within the plasma membrane, we know that D is are correct. Answer. So the only answer for a problem for is D

Mhm. So to answer this question we have to know about sensory receptors. And um the type of energy the neurons have uh is electrical signals, neuron um communicate or send signals in the form of electrical signals. So a sensory receptor absorbs energy from stimulus. So once you absorb an energy from stimulus the first thing you do is okay you absorb energy from stimulus and then you can work that energy into that electrical energy uh into receptor potential. And that is known as um energy trance deduction. And after energy trance induction, what happens is that the receptor the receptor potential um converts the signal. Um It trans um the receptor potential um transmit into the sensory in Iran. Uh huh. Okay. Yeah and after it is transmitted into the neuron uh it does an action potential and finally um that it has done an action potential um from the eggs on terminal the new transmitter releases. So for this question um the next step after absorbing energy from a stimulus would be a noted transaction. Yeah. So this would be the second step. So options see is the correct answer.

When a signal binds to a receptor. What does not happen when a signal binds to a receptor breakdown of the receptor two amino acids does not take place. What does actually happen is the activation of receptor enzyme activity, diffusion of the receptor in the plasma membrane and change in confirmation of the receptor protein.

Alright. So problem to in chapter nine asked us all about signal transaction pathways and asked for an accurate description of them. So, um, first going over our response is a, uh says that, um signals need thio pass through the membrane. B says that, um, cell response on the interior, um, is triggered from an exterior source. C says the opposite of that. That an exterior a sources triggered from something within the cell. And then D says, um, pathways air on lee found when the signal crosses over the membrane. So let's go through these, um A with the necessary for signals to cross the membrane. I'm gonna pop on over here to this diagram. And these signals that are going through our quote going through the membrane aren't really passing through the membrane at all. There are these on the external side of this, so I'm gonna call this the internal side and these Liggins, which we oh thes lie Ganz bond to receptors. Recep tors. So once these two are bonded, um, in the active site than, um in intracellular um, lie again. If you will bonds to the opposite side of this receptor, and there maybe a passage of positive or negative ions, and this pathway could continue into another, um, receptor. And it could keep going, um, until the final product is achieved. So nothing is really passing straight through the membrane. That's not happening. It's all going through the's receptors, so nothing is crossing the membrane. So a is incorrect. Um, be we already talked about this inter cellular response from the external environment. So be, we know has to be correct. See is the opposite. But a signal transaction pathway does not, um, occur out in, um, this, um, open space. It all occurs within within the cell, so see is false. And then D says, is on. Lee found in phase in situations where the signal crosses the membrane. But we already discussed. There's nothing physically permeating the membrane. It's all going through these receptors, so D is false. And the only answer to a problem, too, is B.