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What Is The Role Of The Hormone Glucagon In Regulating Blood Glucose Quizlet

Hormones

Hormones

Sort What's the deal with glucose uptake by cells? When blood glucose drops below the normal range, the release of glucagon promotes the release of glucose into the blood from energy stores, such as liver glycogen, increasing the blood glucose concentration Cells will either store or burn glucose but the liver takes up glucose and makes a polymer out of it -glycogen has a similar structure to starch -most of our energy storage is in the form of fat What's the deal with glycerol and amino acids? blood glucose levels too low --> amino acids and glycerol converted int glucose (through glycogen hydrolysis) and glucose is released into the bloodstream when the blood glucose levels decreases to a level at or below the normal range, a primary effect of glucagon is to signal liver cells to increase glycogen hydrolysis, convert amino acids and glycerol to glucose, and release glucose into the bloodstream What can happen when fat becomes the main substrate for cellular respiration? -pH level increases, ion balances are imbalanced -In severe case, acidic metabolites formed during fat breakdown accumulate in the blood, threatening life by lowering blood pH and depleating sodium and potassium ions from the body -if not respiring glucose enough, then you lower your carbs so your body will break down fat -you can increase level of CO2 but that messes with the pH of blood Continue reading >>

Hormonal Regulation Of Blood Glucose Levels

Hormonal Regulation Of Blood Glucose Levels

Hormonal Regulation of Blood Glucose Levels Brief Overview of Hormonal Regulation of Blood Glucose Levels What is the predominant tissue involved in RESPONDING to signals that indicate reduced or elevated blood glucose levels? What cells secrete insulin? What is insulin's primary role? beta cells of the islets of Langerhans; it is the ONLY hormone that lowers blood glucose. Elevated blood glucose triggers release of insulin from pancreatic beta islet cells. How does insulin alter the metabolic pathways of glucose metabolism? enhances the synthesis of glycogen, lipid & protein while inhibiting the breakdown of glycogen It is synthesized as a precursor called preproinsulin, a single chain polypeptide. Proinsulin is a further edited rendition (N-terminal signal sequence removed) made up of B chain, C chain & A chain. The C peptide (C chain) is cleaved out to form insulin. Where is preproinsulin stored after synthesis? In vesicles in the beta islet cells of the pancreas Describe how insulin ends up being released from the beta islet of Langerhans cells? Describe the role of Calcium. Excess blood glucose. Glucose flows into the beta cells via GLUT 2 & 4, glycolysis-TCA-ETC takes place, dramatically increasing intracellular concentration of ATP. Increase in intracellular ATP blocks ATP dependent K+ channels (KATP), leading to depolarization of cell, leading to opening of voltage gated calcium channels permitting inflow of Ca2+. Ca2+ can attach onto preproinsulin vesicles causing them to fuse w/ the PM. Ca2+ can also bind to CREB (Calcium Responsive Element Binding Protein) on DNA to upregulate transcription & translation of insulin gene. What is the role of GLP-1 (Glucagon-like protein 1) in insulin secretion? When is it released and what is its effect on insulin secretion? Continue reading >>

Phys Exam 5: Regulation Of Metabolism

Phys Exam 5: Regulation Of Metabolism

- Normal fasting blood glucose = 70-110 mg/dL - Minimal glucose needed for brain = 40 mg/dL (below this cognitive deficits, even coma) - Saturating glucose concentration for renal proximal tubules = 180 mg/dL (no glucose in urine unless blood glucose is above this level) - Insulin is the most important regulator of plasma glucose concentration! - Absorptive state = elevated levels of insulin - Postabsorptive state = lowered levels of insulin - Secreted from Beta cells of pancreatic Iselts of Langerhans - Absorptive State: Increased blood glucose stimulates insulin secretion - Target cells express insulin receptor that responds to increase in plasma insulin concentration to stimulate storage of nutrients Preproinsulin: is an amino acid chain with a signaling sequence. Proinsulin: Signal sequence removed, insulin folded with C-chain connecting A-chain and B-chain, which are connected by disulfide bonds. Insulin: A-Chain and B-Chain, C chain has been removed. 1. Increases uptake of nutrients into tissues (mainly skeletal muscle and adipose tissue, NOT LIVER) 2. Stimulates synthesis of storage form of nutrients (Glycogen, protein, triglycerides) 3. Inhibits metabolism of stored nutrients (Glycogenolysis, proteolysis, lipolysis) Insulin does NOT increase liver uptake of glucose. Adipose tissue and muscle express insulin-responsive Glut4, liver does not. Insulin stimulates rate limiting enzyme for glycogen synthesis in muscle and liver. Protein is not storage form of energy, but it is important for maintaining cell health and function, so want to produce and conserve protein. Insulin stimulates amino acid uptake into liver and skeletal muscle and promotes protein synthesis (by stimulating ribosomal enzymes). Insulin also inhibits enzymes involved in protein catabolism. *Insu Continue reading >>

Regulation Of Blood Glucose

Regulation Of Blood Glucose

usually estimated 8-10hrs after the last meal (normal <126mg/dL) as the levels decrease, the -cells of the pancreas are inhibited and the -cells of pancreas is stimulated. as a result, insulin levels fall and glucagon levels rise (decreased insulin:glucose ratio) - glucagon binds to cell surface receptors and activates adenylyl cyclase that increases cAMP which activates PKA and results in phosphorylation of regulatory enzymes before glucagon binds, glycogen phosphorylase is INACTIVE - glycogen phosphorylase is ACTIVE on phosphorylation (covalent modification) and glycogen synthase is inactive on phosphorylation (rapid effect). gluconeogenesis becomes active (slower effect) effect of glucagon on glycogen metabolism glucose increased from phosphorylation of glycogen phosphorylase which activates gluconeogenesis, while phosphorylation deactivates glycogen synthase and thus deactivates glycogenesis - takes place in just a few minutes role of glucagon on gluconeogenesis in liver becomes active due to decreased F2,6BP in liver, increased flux of amino acids and glycerol that are precursors, and induction of key enzymes (PEPCK, pyruvate carboxylase, F1,6BPase, G6Pase) - liver starts producing glucose rather than utilizing it. you must maintain blood glucose for the brain function allosteric modulator - stimulated by insulin, it activates PFK-1 and thus glycolysis to increase production of pyruvate and decrease production of glucose, plus it inhibits F1,6BPase allosteric modulator - inhibited by glucagon, PFK-1 is inhibited and F1,6BPase is activated thus activating gluconeogenesis production of glucose and inhibiting glycolysis it is a hyperglycemic hormone that binds to the receptor in the liver cell membrane and results in activation of glycogenolysis by covalent modificat Continue reading >>

Biomed Flashcards | Quizlet

Biomed Flashcards | Quizlet

Diabetes is elevated blood glucose levels How is glucose tolerance testing used to diagnose diabetes? after drinking a sugary drink it tests the amount of glucose in the blood after two hours How does the development of type 1 and type 2 diabetes relate to how the body produces and uses insulin? Type one produces little to no insulin and type two produces ineffective insulin What is the relationship between insulin and glucose? When glucose is put into the blood the pancreas releases insulin How does insulin assist with the movement of of glucose into body cells? The insulin wakes up the cell so that the glucose can enter. What does feedback refer to in the human body? how the body responds to get to homeostasis How does the body regulate blood glucose levels? the pancreas releases glucagon which causes the liver to turn stored glycogen into glucose which is then released into the bloodstream regulating the bgl a protein hormone secreted by pancreatic endocrine cells that raise blood glucose levels. a product of living cells that circulates in the bloods and produces a specific, stimulatory effect on the activity of the cells. type of homeostasis whereby a change in your body causes a physiological variable to counteract the normal fluctuation feedback that tends to magnify or increase a processes output form that usually develops during childhood,characterized by severe insulin deficiency that leads to high blood glucose levels. form that usually develops in adults that are most often obese. Characterized by high blood glucose resulting from the body not being able to use insulin leading to increased insulin production. patient has increased thirst and is very fatigued, the doctors tell the patient that their pancreas is not functioning properly. what effect on the bo Continue reading >>

Pogils - Chapters 26 & 32

Pogils - Chapters 26 & 32

ex: temp too low= muscles begin to shiver, blood vessels in skin constrict temp too high= blood vessels dilate, sweat glands & Contraction of the uterine wall Would a positive feedback loop ever be helpful in maintaining homeostasis? no, because as a positive feedback loop continues it gets you further and further from the normal Would a single negative feedback loop ever be helpful in maintaining homeostasis? No, because a single one is not enough, the body needs a mixture of both positive and negative in order to maintain homeostasis Human tissue being torn or cut is an example of... more and more platelets are being produced in order to "fix" cut As blood glucose levels increase above baseline, the level of which hormone also increases? as blood glucose level begin to drop below baseline, the concentration of which hormone increases? Three organs/ tissues that interact to regulate blood glucose levels where does insulin and glucagon originate what is the role of insulin in maintaining glucose levels after a large meal? Insulin helps glucose be moved into storage in the liver and helps it be used for energy. It is important to move it to storage so that our bodies can use it for later throughout the day to maintain energy what is the role of glucagon in maintaining glucose levels when the organism is hungry? It transforms glycogen into glucose that the body can then use for energy Predict levels of glucose, glucagon, and insulin Continue reading >>

Homeostasis: Hormones And The Regulation Of Blood Glucose Concentration 16.3

Homeostasis: Hormones And The Regulation Of Blood Glucose Concentration 16.3

What are both the hormones that the pancrease produces used for? Regulating the blood glucose concentration. Cells that produce its digestive enzymes. What other, less common, cells is the pancreas made up of? Hormone-producing cells called islets of Langerhans. What two types of cells are included within the islet of Langerhans cells? - Alpha cells, which are smaller and produce the hormone glucagon. - Beta cells, which are larger and produce the hormone insulin. To regulate the blood glucose concentration. What three important process takes place within the liver, which relate to regulating the blood glucose level? - The conversion of glucose into glycogen. - This happens when the blood sugar level is above the normal. - The glucose in the blood is removed by the liver. - Glycogen is stored so that it can maintain a human's blood glucose concentration for 12 hours (at rest), in the absence of other sources. - The breakdown of glycogen into glucose, by the liver. - This occurs when the blood glucose concentration is lower than normal. - The glucose diffuses into the blood to restore the blood glucose concentration to normal. - The production of glucose from sources other than carbohydrate. - This occurs when the supply of glycogen is exhausted, the liver then produces glucose from non-carbohydrate sources such as glycerol and amino acids. In what other biological process is glucose need for? Why is the maintenance of a blood glucose level essential? For respiration as it is the main source of energy. What is the result of a lower than normal blood glucose level? - Cells will be deprived of energy and die. - Brain cells are especially sensitive as they can only respire on glucose. What is the result of a higher than normal blood glucose level? - Lowers the water potent Continue reading >>

Final- Type Ii Diabetes

Final- Type Ii Diabetes

What is considered to be a normal blood glucose range? Why do physicians measure blood glucose levels during fasting for accurate readings? Because a blood glucose level above 110 mg/dl is normal if one has consumed food in the past 2-3 hours Low blood sugar... when your blood glucose level <70 mg/dl high blood sugar... when your blood glucose level is >180 mg/dl What two pancreatic endocrine hormones are blood glucose levels regulated by? insulin and glucagon; both are secreted by islet cells in the pancreas What is the function of the hormone insulin in blood glucose regulation and what type of cell in the pancreas is it released from? when there is high blood glucose levels, insulin is released from pancreatic beta cells to facilitate absorption of glucose out of the blood in order to lower blood glucose levels What types of cells does glucose act on? (3) What is the function of the hormone glucagon in blood glucose regulation and what type of cell in the pancreas is it released from? when there is low blood glucose levels, glucagon is released from the pancreatic alpha cells in order to cause the liver to release stored glucose into the bloodstream and raise blood glucose levels What is the main organ that glucagon works on? What is Type I Diabetes characterized by? What do Type I Diabetes patients do to regulate glucose intake? damage to the cells that secrete insulin from the pancreas, which prevents insulin production in the body; these people need daily insulin rejections to regulate glucose intake What is Type II Diabetes characterized by? insulin resistance which prevents the body from using insulin efficiently which could eventually lead to insulin deficiency which is when the pancreas produces less insulin over time About how many people in the U.S. suffer Continue reading >>

Regulation Of Glucose Through The Hormones Insulin And Glucagon

Regulation Of Glucose Through The Hormones Insulin And Glucagon

Sort Hyperglycemia High blood glucose. High blood glucose happens when the body has too little insulin or when the body can't use insulin properly.Term used to describe hormones such as glucagon that elevate blood glucose levels. If you have type 1, you may not have given yourself enough insulin. If you have type 2, your body may have enough insulin, but it is not as effective as it should be. You ate more than planned or exercised less than planned. You have stress from an illness, such as a cold or flu. Youve just attended a football game with your friend sharon who is diabetic. While sharon drank only one beer during the game she is having trouble walking straight her speech is slurred and she is not making sense. what does it mean when we say sharon is diabetic? what is the most likely explanation for sharons current behavior? how could you help her? when we say sharon is diabetic this means that she has insufficient insulin action in her body. the most likely explanation for sharons behavior is that she has taken too much insulin and is experiencing hypoglycemia. You could help her by making sure she gets a sugary snack. Continue reading >>

Nutrition Chapters 4 Study Questions

Nutrition Chapters 4 Study Questions

are a category of single sugar molecules that are absorbed easily in the small intestine. consist of two molecules of sugar joined together. is the most abundant sugar molecule, and the preferred source of energy for the brain. are a category of nutrient compounds consisting of long chains of sugar molecules. is a type of simple carbohydrate composed of a glucose molecule and a fructose molecule. Plants store glucose as polysaccharides in this form. The storage form of glucose in humans and animals. What are the enzymes that are responsible for the break down of starches? What enzymes are responsible for breakdown of disaccharides? These are absorbed by the small intestine and enter the bloodstream. Insulin is produced and released from the? In response to insulin or glucagon, either glycogenesis or gluconeogenesis, respectively will take place in the ? The body can either use ________ for energy, convert to glycogen, or store it as fat. what occurs when blood glucose levels drop below 70 mg/dl? As part of the response to increased blood glucose after a meal, Insulin triggers the of _____________________ on the cell membrane in the body to be increased. What is a key hormone produced by the pancreas that plays a key role in regulating blood glucose levels after a meal? What is the storage form of glucose in the liver and muscles of humans and animals? What is glucose converted to for storage in fat tissue? What is the key hormone produced by the pancreas that plays an important role in regulating blood glucose levels during times of fasting? hormones that have no effect on blood glucose levels? Continue reading >>

Regulation Of Blood Glucose Levels

Regulation Of Blood Glucose Levels

Sort Hormonal regulation of blood glucose levels Insulin and Glucagon: - Respond to blood glucose levels Epinephrine: - 'Fight or flight' response Cortisol: - Stress reaction Homeostasis Blood glucose level: High Stimulus: - Rising blood glucose level (e.g after eating) - Beta cells of pancreas stimulated to release insulin into the blood. - Insulin = body cells take up more glucose/ liver takes up glucose and stores it as glycogen. - Blood glucose level declines to a set point- stimulus for insulin release diminishes. Effects of insulin on blood glucose: Plasma glucose increases: - Beta cells in pancreas = secretion of insulin increases. - Fatty acid synthesis (liver)/ TAG synthesis (adipose tissue) Most tissues: - Increase of glucose uptake into cells. Liver and muscle: - Increase glycogen synthesis - Decrease glycogenolysis Liver: - Decrease gluconeogenesis = Decrease in plasma glucose. Effects of glucagon: - Plasma glucose decreases - Plasma amino acids increases - Sympathetic activity increases - Epinephrine secretion increase = Alpha cells in pancreas secretes more glucagon. Liver: - Increases glycogenolysis - Decreases glycogen synthesis - Increases gluconeogenesis - Increases ketone synthesis - Increases protein breakdown - Decreases protein synthesis Adipose tissue: - Increases lipolysis - Decreases triglyceride synthesis Fuel metabolism in the liver during starvation: 1. Protein degradation yields glycogenic amino acids. 2. Urea exported to the kidney and excreted in the urine. 3. Citric acid cycle intermediates are diverted to gluconeogenesis. 4. Glucose is exported to the brain via the bloodstream. 5. Fatty acids (imported from adipose tissues) are oxidised as fuel, producing Acetyl CoA. 6. Lack of oxaloacetate prevents Acetyl CoA entry into the CAC, acetyl- Continue reading >>

Nutrition Chapter 3&4

Nutrition Chapter 3&4

is the process by which foods are broken down into molecules is the process of taking the products of digestion across the gastrointestinal tract walls and into circulation is the process by which undigested food and waste products are excreted from the body -Cephalic phase is the earliest phase of digestion; the GI tract prepares to digest food -Chewing moistens food and mechanically breaks it down -Saliva moistens food and begins chemical digestion of food via the enzyme amylase, which begins the process of carbohydrate digestion: enzymes are proteins that speed up chemical reactions. enzyme names typically end in ase The esophagus propels food into the stomach -The mass of food that has been chewed and moistened in the mouth is referred to as a bolus -the bolus of food is swallowed and moves through the esophoagus to the stomach by peristalsis: peristalsis is the rhythmic contraction and relaxation of circular and longitudinal muscles that move food in one direction through the GI tract -Food passes into the stomach through the gastroesophageal sphincter The stomach mixes, digests, and stores food -Gastric juice contains several important compounds: Hydrochloric acid keeps the stomach interior acidic and starts to denature protein. Pepsin begins to digest protein and activates other enzymes. Gastric lipase is an enzyme responsible for fat digestion. -Mucus protects the stomach lining from being digested -The stomach mixes food until it becomes a liquid called chyme -Chyme is periodically released into the small intestine through the pyloric sphincter Most digestion and absorption occurs in the small intestine -The gallbladder aids in digestion by releasing bile to emulsify fat The pancreas aids in digestion by secreting various enzymes that digest carbs, fats and pr Continue reading >>

Ch 15.2 Hormones That Affect Blood Sugar

Ch 15.2 Hormones That Affect Blood Sugar

Sort Islet Cell Transplant Why? To be a treatment for diabetes; holds potential to reverse diabetes. +this transplant surgery is low risk, person goes home the next day. Islet cells are extracted from the donor and infused into the recipient's liver via the a large vein.Liver is used as it can regenerate itself. New blood vessels and nerves connect to the transplanted islet cells in the liver and they produce enough insulin to control blood sugar. -immune rejection as current anti-injection drugs are toxic and harmful to islet function What happens in fright-or-flight (short term stress response)? The nervous system and the adrenal medulla are linked in that they both produce epinephrine. The hormone producing cells in the adrenal medulla are stimulated by the sympathetic nervous system in times of stress. The cells in the hypothalamus send signals to nerve cells in the spinal cord. Spinal cord cells stimulate adrenal medulla to secrete epinephrine and norepinephrine. Result: increase blood sugar levels, increase heart rate, breathing rate, and cell metabolism, blood vessels and pupils dilate. ***short term stress: Adrenal Medulla What happens during a long term stress response? The brain identifies the stressful situation. The hypothalamus sends a releasing hormone to the anterior lobe of the pituitary, stimulating it to secrete ACTH, a tropic hormone. ACTH targets cells in the adrenal cortex, causing cells in the adrenal cortex to secrete mineralocorticoids and glucocorticoids (among them cortisol) which get carried to target cells in liver and muscles. As cortisol levels rise, cells within the hypothalamus and pituitary decrease the production of regulatory hormones, and eventually the cortisol levels fall. ***Long term stress: adrenal cortex Pancreatic Transplantati Continue reading >>

Nutrition 5 Flashcards | Quizlet

Nutrition 5 Flashcards | Quizlet

SUGARS. monosaccharides (one-unit sugars) and disaccharides (two-unit sugars). Monosaccharides include glucose, fructose and galactose. These can be absorbed directly and don't require further breakdown from enzymes, unlike disaccharides and polysaccharides. STARCHES AND FIBERS. A nutrient compound consisting of long chains of glucose molecules, such as starch, glycogen, and fiber fiber that dissolves in water and slows down digestion to give you that "full feeling". Oatmeal, berries, and beans are all good sources. consuming this reduces the risk of cardiovascular disease and type 2 diabetes. fiber that does not dissolve in water. Adds bulk to diet and helps with constripation by having that "laxative" benefit. Found in wheat, rye, brown rice, and many veggies. 1. begins in mouth when starch in foods meet with saliva. saliva contains the enzyme salivary amylase, which breaks down starch into smaller particules and eventually into disaccharide maltose. 2. the bolus of food leaves the mouth and enters the stomach, where all digestion stops. the acid in the stomach inactivates the salivary amylase. 3. majority of digestion occurs in the small intestine. as the contents of the stomach enter the small intestine, an enzyme called pancreatic amylase is secreted by the pancreas into the small intense. Pancreatic amylase continues to digest any remaining starch into maltose. 4. once digestion is complete, all monosaccharides are then absorbed into the mucosal cells lining the small intestine, where they pass through and eneter into the bloodstream. they then travel to the liver. it will either be stored in the liver or muscle or used for energy. Various hormones are involved in regulating blood glucose. Insulin lowers blood glucose levels by facilitating the entry of glucose i Continue reading >>

Human Ap2 Chapter 13

Human Ap2 Chapter 13

glands of "internal secretion" whose secretions are usually secreted directly into the blood. Released externally, have ducts to carry their secretions to specific locations. affects only the secreting cell or itself Why do hormones affect only target cells? A hormone is a secreted biochemical that affects the functions of another cell. A target cell is a cell that possesses specific receptors for a particular hormone. Thus, a hormone affects only its specific target cell Steroid hormones act directly, and alter gene expression. They usually bind to receptors inside the cell, forming a complex that binds to DNA and activates transcription. Non-steroid hormones act indirectly, and activate proteins. They bind to receptors on the cell surface and trigger production of a second messenger or a phosphorylation cascade, ending in activation of proteins already present in the cell. sequence of actions of non steroid hormone 3.Adenylate cylase molecules are activated in target cells membrane 5. Protein kinases are activated that change metabolic processes 6. cellular changes produce hormones effect How do the steroid and nonsteroid pathways differ in speed of action? Amplification? Steroid path is slower. Nonsteroid has amplification of signal. What are the four examples of steroid hormones Estrogens,testosterone, aldosterone, cortisol are paracrine substances that have powerful hormone like effects, even in small amounts, causes smooth muscle to relax in the airways of the lungs and in the blood vessels. promote inflammation when tissue is injured 8. Some drugs, such as aspirin, inhibit production of prostaglandins. How can these drugs cause unwanted side effects? cause menstrual cramps and labor contraction 9. What is an NSAID? Give two familiar examples Non-Steroidal Anti-I Continue reading >>

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