BIOL 101 Guided Reading Questions GRQs Complete and submit this GRQ as a PDF before lecture and before your online Mastering Assignment L5 GRQs Cell Signaling with Hormones Reading Objectives Differentiate between chemical and electrical signaling to cells Describe how the two types of chemical signaling mechanisms affecting target cells differently Explain the consequences of endocrine disruptors Explain how testosterone and estrogen affect gender development Explain how enzymes are inhibited Identify functions of enzymes and the conditions they work best Modules 26 1 2 Chemical and electrical signals coordinate body functions Hormones affect target cells using two main signaling mechanism 1 What two type of signals does the body use to communicate The body uses chemical and electrical signals travelling from the endocrine system and the nervous system to communicate The endocrine system releases hormones that travel through the bloodstream to all other parts of the body while the nervous system transmits electrical signals to nerve cells through neurons 2 How do they affect different responses in the body The endocrine system makes gradual changes that affect the entire body while the nervous system is responsible for immediate and rapid responses 3 What does a target cell have that allows it to respond to a hormone secreted from a distant gland that a non target cell is lacking Target cells have receptors for a specific hormone that is secreted as opposed to a non target cell 4 List and describe the three stages of hormone signaling 1 Reception occurs when a hormone binds to a specific receptor protein or in the target cell 2 SIgnal Transduction when a molecule of the hormone reaches the receptor protein and triggers events within the target cell converts signals from one form to another 3 Response a change in the cell s behavior 5 Are hormone receptors on the plasma membrane or inside cells Hormone receptors are in both the cell and the plasma membrane 6 Draw a quick diagram outlining the differences between water soluble hormone signaling vs lipid soluble hormone signaling 7 Why can steroid hormones pass through the plasma and nuclear membranes Steroid hormones can pass through the plasma and nuclear membrane because they are lipid soluble hormones Modules 26 8 9 Diabetes is a common endocrine disorder The adrenal glands mobilize responses to stress 1 What organ secretes insulin and glucagon Pancreas 2 What are the target cells of insulin What affect does insulin have on cells The target cells of insulin are liver and skeletal muscle cells Insulin stimulates nearly all cells to take up glucose and the liver and muscle cells use glucose to form glycogen stores 3 What are the target cells of glucagon What affect does glucagon have on target cells The target cells of glucagon are liver cells Glucagon causes the liver to secrete glucose and return it to the blood 4 Diabetes as a group of diseases affects 1 in 11 Americans What is diabetes Diabetes is a hormonal disorder caused by the body s inability to produce or use insulin which decreases the absorption of glucose from the blood This results in elevated levels of blood glucose Cells are starved for fuel and burn through the body s supply of fats and proteins but the digestive system continues to absorb glucose from food 5 Compare and contrast the differences in hormone signaling defects in type 1 vs type 2 diabetes Type 1 diabetes is an autoimmune disorder where the body s own immune system attacks and destroys the pancreatic beta cells that release insulin As a result the pancreas does not produce enough insulin WIthout sufficient levels of insulin target cells do not receive the signal that leads to glucose transporters being moved to the plasma membrane This results in blood glucose levels being elevated In type 2 diabetes insulin is produced but the signal is not relayed normal inside the target cells These beta cells adapt to the defective signaling by producing even greater amounts of insulin even though it is present the glucose transporters are not readily available to take the glucose from the blood and these cells are said to be insulin resistant 6 What condition occurs if too much insulin is produced or injected If too much insulin is produced hypoglycemia can occur which can lead to convulsions or death ADDITONAL KNOWLEDGE FUN Check out this short 2 min video to about diagnosing diabetes Take notes if it helps you https www youtube com watch v bIhy Rb2xp4 Module 5 13 and 5 14 Enzymes speed up the cell s ractions by lowering energy barriers A specific enzyme catlayzes each cellular reaction 1 What does the activation energy of a chemical reaction specifically do to reactants Activation energy activates the reactants the energy is absorbed to control or weaken bonds in reactant molecules so that they can break and new bonds can form 2 What do enzymes do to the activation energy The enzymes speed up the reaction by lowering the activation energy needed for a reaction to begin 3 Draw a graph with two lines One line will represent a reaction without an enzyme and the other line will represent an enzyme catalyzed reaction Your Y axis should be labeled as increasing energy and your X axis should be labeled progress of reaction Be sure to label the activation energy for both reactions 4 True or False Defend you answer for each i e explain why a particular statement is true or correct a false statement False Enzymes are consumed in reactions they are not consumed because they go on to catalyze other reactions True Substrate is another word for reactant A substrate is the reactants that an enzyme works on True An enzyme and a substrate will bind to each other Enzymes and substrates bind at the active site of an enzyme True Enzymes are specific to substrate Enzymes are specific because only certain substrate molecules fit into their active sites True Active site refers to a part of the enzyme An active site is the part of an enzyme where a substrate binds False Enzymes are always proteins they are usually proteins not not always as RNA sometimes functions as an enzyme 5 What conditions do most enzymes work best at Explain how the optimal conditions are related to the shape of molecules such as proteins Enzymes work best in neutral temperatures and pHs around 35 40 degrees celsius and pH 6 8 The optimal conditions are needed because if the environment becomes too acidic or the temperatures are too high then the protein will
View Full Document
Unlocking...