Metabolic Fuel Sources in the Fed and Fasting State Published on August 30, 2020 by ehudspeth Metabolic Fuel Sources in the Fed and Fasting State Your friend Tiffany was only half listening about leptin and is confused as to why it couldn’t be used independently to treat obesity in humans. Which of the following explains why this would not be an effective obesity treatment for humans? Leptin is only found in mice Leptin alone couldn’t work, it would have to be used in conjunction with peptide Y which has not been purified and isolated Leptin is already secreted, its signal is ignored by individuals and eventually they become leptin insensitive Leptin is already secreted, but it is less efficient when there is more adipose tissue Leptin is only released when exercising, so giving it to obese patients would not be effective unless they are active. After running a routine physical and blood tests on a patient, they begin to freak out because their blood glucose level is 135! They are very healthy, non obiese 35 year old male, and have no history of diabetes in their family. What is the most likely cause of the high blood glucose levels? They may be pregnant and developed gestational diabetes They have developed a mutation and have started to become a type 1 diabetic They are so sensitive and sweet to other people they just have a normally elevated blood glucose level They drink too much diet soda with aspartame which is known to raise blood glucose levels They didn’t listen like most people and ate 2 hours before their exam All of the following Gluconeogenic mechanisms are stimulated by increased levels of Glucagon, except for: Phosphorylated Pyruvate Kinase Increased PEPCK gene transcription Increased hepatic Fructose 2,6-bisphosphate Increased cAMP Phosphorylated (PFK-2/FBP-2) Martha tells you that she has been doing the keto diet where she eats fewer than 20 grams of carbohydrates a day. While on this diet, what does her red blood cells use for fuel? They will switch to using ketone bodies to run glycolysis They will function on the 20 grams of carbohydrates that she consumes per day They will rely more heavily on gluconeogenesis to create glucose They will switch to using fats to create energy through β-oxidation They will break down amino acids from the increased protein she is consuming. A patient has bloodwork done two hours after consuming a sugary drink. Since consuming the drink, the patient has consumed no other food or beverages. The patient’s blood glucose level is 163 mg/dL. What can be said about the patient? The patient’s results are considered normal. The patient is considered pre-diabetic. The patient is considered diabetic. The patient is not producing insulin. The patient is not producing insulin. Lauren, an OMS I student, is celebrating her outstanding performance on the anatomy exam by hitting the dance floor at the Electric Cowboy (she’s got Flossing down!). She realizes that she forgot to eat dinner, but doesn’t want to leave to grab a meal. She opts to pile on the drinks because, after all, alcohol has carbohydrates and she’ll be satisfied (at least for a little bit). How will her body respond? Lowering the activity of aldehyde dehydrogenase Increasing gluconeogenesis NADH levels will decrease but rapidly start increasing Initial hyperglycemia, but soon her body will become hypoglycemic Initial hypoglycemia, but soon her body will become hyperglycemic Pig insulin was regularly administered to diabetic patients before the structure of human insulin was discovered. Now that the structure is known, doctors are able to administer the active portion of insulin, while still being able to measure the amount of insulin being produced by the body. Which part of human-secreted insulin is measured? A-chain B-chain Proinsulin C-peptide Insulin You are on a pediatrics rotation when a 5-year-old female patient is brought into the clinic by their mother. The patient is severely obese. However, the mother mentions that her daughter’s nutrition is good but she is constantly hungry. What is the next thing you should do? Refer them to a nutritionist Test for a Leptin deficiency Test for AMPK deficiency Test for brain damage within the hypothalamus Test for Type I Diabetes mellitus After consuming glucose, insulin production is turned on, whereas glucagon is turned off. Which of the following is true in the fed state? Glycogen synthesis is inhibited by the increase in insulin. Fatty acid synthesis is inhibited by glucagon to maintain blood glucose levels. Lactate production is increased, resulting in an increase in glycogen synthesis. Fatty acids are broken down to maintain blood glucose levels. Glycogen synthesis is stimulated by insulin and stored in the liver and skeletal muscle. Ahsan, a mentally exhausted medical student, decided to take a study break and go for a hike at Devil’s Den. He accidentally travelled off the beaten path when he heard some unusual noises coming from the brush. Luckily Ahsan is a highly trained eagle scout and recognized the sounds immediately as the call of a cougar. He sprung into action, boldly running from the noise and flooding his body with adrenaline. Assuming that Ahsan had eaten a meal high in carbohydrates within an hour of this occurrence, which of the following is true? Epinephrine will activate a tyrosine kinase receptor signaling pathway causing the breakdown of Glycogen. His high BGL would trigger a release of Insulin and the dephosphorylation of Glycogen Synthase by Protein phosphatase. Glucagon would be released causing the activation of PKA and the subsequent dephosphorylation of Glycogen synthase and phosphorylase kinase. Despite his high BGL, Epinephrine will work in a similar manner to that of Glucagon causing the phosphorylation of Glycogen synthase and Glycogen phosphorylase. Epinephrine will activate a similar signaling cascade to that of Insulin, causing an activation of PKB (Akt) and subsequent phosphorylation of Glycogen synthase. In preparation for board game night, Seth and Ed each brought their favorite snacks to enjoy throughout the night. Shortly after eating all of his doughnuts, Seth was already hungry again. Ed, however, was still feeling quite content after eating his quinoa and mushrooms. What is the likely cause for this discrepancy? The fructose content in Ed’s quinoa was converted to fat, which has twice the calories of carbs, it’s simple science. Seth’s doughnuts have a high glycemic index, causing a large, but short spike in blood glucose Seth’s doughnuts absorb at a slower rate, so he isn’t getting as much energy from them Ed’s quinoa has a high glycemic index, causing a prolonged spike in blood glucose Seth’s donuts had a high abundance of Fructose, causing glycolysis to occur unchecked and create an abundance of ATP Dr. Moffitt is running yet another ultramarathon. As she approaches mile 20, she decides to reach for her gel packet tucked conveniently within her fanny pack in order to get some energy. The gel packet contains a high amount of Fructose. Which of the following is true regarding Dr. Moffitt’s decision to consume this gel packet? It’s obviously a mistake, Fructose will be converted to fat which won’t be burned in time to give Dr. Moffitt energy Since she is undergoing prolonged exercise, Dr. Moffitt is burning ATP at an high rate and therefore can utilize the Fructose without producing an abundance of fat This is a good choice since Fructose will initiate Gluconeogenesis in the liver Fructose will undergo glycolysis without being regulated, therefore her consumption of this sugar will lead to an accumulation of fat which can be burned for energy A glucose-only gel packet would have given her the same amount of energy One of your patients is Type II diabetic. In order to help them increase their insulin sensitivity you recommend more frequent exercise which you expect will: Lead to higher levels of insulin in the body Promote recruitment of more GLUT4 receptors Increase skeletal muscle of utilization of insulin during exercise only Increase insulin synthesis by pancreatic beta cells Decrease skeletal muscle utilization of insulin during rest only Glucagon signaling will do which of the following in the target cell? Decrease cAMP levels Activate protein phosphatase-1 Deactivate glycogen phosphorylase-a Increase glucose-1-phosphate levels Lower 5′-AMP levels Time is Up!