Can gluconeogenesis and glycolysis occur at the same time?
When discussing these pathways, it is important to recognize that glycolysis occurs in all tissues but gluconeogeneis is primarily in liver and kidney, with limited amounts in small intestine and maybe other organs. Tissues/cells with very high dependence on glycolysis (red blood cells, brain) do not do gluconeogenesis. Thus, even when gluconeogenesis in occurring in one place (the liver), glycolysis is occurring in other tissues (muscle, RBCs, brain).In the body overall, the hormonal controls are reciprocal for these opposite pathways, i.e., glycolysis is stimulated by insulin and decreased by glucagon, whereas gluconeogeneis is stimulated by glucagon and decreased by insulin. These hormonal actions are via key regulatory enzymes in both glycolysis (hexokinase, PFK-1, pyruvate kinase) and gluconeogenesis (pyruvate carboxylase, PEP carboxykinase, fructose-1,6-bisphosphatase, glucose-6-phosphatase). There is also longer term control via hormonal activation/blocking of specific genes in target tissues (e.g., liver).In some scenarios, these overall controls can be overridden when considering different organs/tissues/cells. Liver can be performing gluconeogenesis (say, from a protein meal) while at the same time skeletal muscle can be performing glycolysis during a brief burst of contraction (maybe a sprint).Due to the reciprocal nature and control of these pathways, they should not be running simultaneously in the same cell. Also, keep in mind that the creation of free glucose from a 3-carbon precursor such as pyruvate requires 6 ATP, whereas the net production from glycolysis is only 2 ATP. It always costs more to build than to break down. This is consistent with laws of thermodynamics. The energy considerations make it pretty much impossible to run both pathways simultaneously in the same cell, though as discussed above they can and do occur simultaneously in different tissues of the body.The transport of glucose into cells via glucose transporters (GLUTs) is also a key consideration, but especially for tissues that have the insulin dependent GLUT-4 type (muscle, fat). Tissues with other GLUTs are NOT dependent on insulin to take in glucose, though insulin’s influence can still be felt via impact on enzymes and/or genes.
What are the mistakes first year MBBS students make that harm them later?
There are Few Mistakes that First Year make That I want to point outPassing the exam: This is the motto i find our colleges teach us from the first day. Entire Course is based on that you should just pass. It is not wrong to pass but the thing is One Must LEARN. The Anatomy is boring with Huge syllabus but the “Calot Triangle” is important landmark for a surgeon. The various injuries of brachial Plexus are important. So learn anatomy in clinical based way and try to understand the landmarks and their importance. The surface marking that no one Pays attention is actually most important. In Clinical Subjects you will need to Find “Anterior Superior Illiac Spine”. Do not ignore the Surface marking,cross section, X-Ray.Medicine is nothing but three P which are Physiology,Pathology,Pharmacology : You are going to have the first P in Physiology. Read it nicely. Understand the concepts like cardiac and muscle conduction. Various Tracts in Spinal cord,Basal Ganglia, Endocrine. Buy Guyton and read it. It is a excellent book.Biochemistry: I know application of Glycolysis and Kreb cycle is not much. But few enzymes deficiency like G6PD are many times asked. To understand Diabetic Ketoacidosis one should know biochemistry. The vitamins that are taught is very important so is few metabolic disease. Metabolic Acidosis and Alkalosis are also importantAs Many answer already mentioned Read standard Book. Grey Anatomy is great but it wont serve the purpose. Stick to BD Chaurasia. Buy Neter Atlas. Read Lippincott for biochemistry. It is a excellent Book. Do not read the Short books that are aimed to pass you in exams.Do not get depress: In your school days you may have got very good marks but it wont be the case here. Lot of Items and exams are conducted and you will feel you cannot handle the stress properly. Do not worry each one of us have passed through this,you will too so keep going. Do not compare Your self with anyone and try to do betterEnjoy Life: It is very important in first year. Do not forget to relax and take things easy. Go out with friends. Do not Limit your self to hostel and college Thank You
Someone has recommended that i feed my tropical fish every 2 days....when i do they r always starving hungry.?
ONCE EVERY TWO DAYS??? Who ever told you that know'as nothing about tropical fish. I feed my angelfish 3 times a day and a variety of food's. My fry even eat as much as 6 time's a day when they are very young and in a critical stage. Twice a day is a good plan to stick by. Try feeding them something other them flake food if you don't alrighty to, like Bloodworm's, Brine shrimp, BBS(baby brine shrimp)for baby fish, beef heart(its messy if you make your own mix and you have to know how lol).You can find all but the beef heart at your local pet store or online if you want. Those are some of the best foods. Throw flakes in once a day and lets say Brine shrimp the other meal and your fish will be happy. EDIT: 2 Thumbs down huh, You people have no clue!!!
Is β-oxidation fast enough to supply energy for an animal in danger (fight-or-flight) which has been starving and has consumed all its glycogen supplies?
Much depends on the species of animal and the circumstances.Animals that run quickly, for short periods, depend heavily on glycolysis. Think of a cheetah, a rabbit, or a human sprinter. Fast twitch muscles, in particular, depend on carbohydrate.Long distance runners depend more heavily on fat oxidation. Think of a horse or a human long distance runner. But they still need some carbohydrate for optimal performance.These statements are based on what we know from a few species: humans, rats, and mice. I haven’t studied the literature on comparisons of other species but this article says that some species preserve muscle glycogen during fasting for emergencies: [1]. It would be interesting to learn whether cheetahs conserve muscle glycogen during a fast. (I doubt that anyone will do that study.)With regard to the question’s comment, it doesn’t make sense to create glucose through gluconeogenesis while you are running, because doing so would force you to take in more oxygen. That’s a problem because the ability to take in oxygen is one of the factors limiting your running speed.If you have access to a university library, this article may help.[2] Consult any textbook of exercise physiology.Footnotes[1] http://ttps://www.researchgate.n...[2] Integrative Physiology of Fasting.
How does fasting affect red blood cells?
Hi there…Fasting is a process during which blood sugar level is decreased and hence, the energy generation is affected. RBCs are heavily dependent on glucose for survival as they have only the glycolysis pathway to generate energy to sustain and survive. During fasting condition, glucose level is hampered subsequently RBC count is decreased to certain extent, if fasting is continued for longer duration, the RBC count dwindle substantially making body weak… very weak….This is worth paying attention to.Personally I got a little fed up of the absolute mess of information the internest throws at you when it comes to fasting. It gets pretty hard to know what to follow, how long to follow it for and half the time it doesn’t work. I mean we wouldn’t all keep hearing about fad diets if one actually met half the promises, right?You can download the Eat-Stop-Eat Audiobook completely free from Fasting TV. It goes back to basics to actually get results: [Free Audiobook] Eat - Stop - Eat: Make Fasting Simple Again (And Get Actual Results)If you haven’t really looked fasting before it can be a murky topic. There’s a lot of inforation to go on, especially online where everyone and their dog have an opinion whether they’re qualified to share it or not.At the most base fasting is an intentional withholding of food. Whether for spiritual or health reasons there absolutely are benefits to it when used correctly.To everyone spouting that it’s all a craze with no backing - I think you’re thinking of detoxing and juice cleanses. Fasting is different and has clear and proven advantages.There is no set duration or way to do it. I’m not going to pretend like I have all the answers because at the end of the day I only know what works for me and a sample size of one is not a reliable study. However I will tell you that the biggest thing you can do for yourself is get at least a basic understanding of what you’re doing. You don’t need to study nutrition for years but don’t just follow along with fad diets or fasts in the hopes of stumbling into something which works.The sad truth is if it was as easy as all that selling us on fake diet crap wouldn’t be such a big market.