HNF 461 Final Exam Study Guide Exam 1 1 AMDR Do not need to know exact numbers but need to know which accounts for the most and the rough ratio a Adults i Carbohydrates 45 65 ii Lipids 20 30 iii Protein 10 35 b Infants i Carbohydrates 45 65 ii Lipids 30 40 iii Protein 5 20 2 What s special about the macronutrient composition of milk compared to normal AMDR Why is it important a Breast milk is composed of mostly fat then carbs and very little protein i Infants need high energy intake for growth and development b Adult diets are composed of mainly carbs and then similar values for proteins and fats 3 Understand what makes a pathway reaction endothermic or exothermic a Endothermic low to high energy state requires energy i Gluconeogenesis b Exothermic high to low energy state releases energy i Metabolism of glucose to pyruvate in glycolysis and the generation of ATP from phosphocreatine in the muscle 4 What is substrate level phosphorylation a Metabolic reaction that results in the formation of ATP b Occurs in the cytoplasm of cells as the first step in glycolysis c Produces 2 ATP 5 How is enzyme activity regulated a Allosteric regulation enzyme reacts with a small molecule which changes the composition of the enzyme no new bonds are formed b De Phosphorylation Removal or addition of a phosphate group new bonds are formed 6 What is the function of AMPK What activates it What pathways does AMPK target a AMPK activated by a decrease in the cell s energy state increased AMP ATP ratio i Phosphorylation of AMP activates AMPK b Stimulation of processes that produce ATP and inhibit those that use ATP i Targets pathways that generate ATP glycolysis and fatty acid oxidation 7 Fate of glucose of cells what is glucose used for a Fuel for ATP synthesis b Glycogenesis c Lower priority functions synthesis of ribose NADHP and glucoproteins lipids d Lowest priority function fatty acid synthesis 8 The starting and end points of glycolysis gluconeogenesis glycogenesis etc a Glycolysis starts with glucose ends with pyruvate b Gluconeogenesis starts with pyruvate lactate glycerol amino acids ends with glucose c Glycogenesis starts with glucose ends with glycogen d Glycogenolysis starts with glycogen ends with glucose 9 The regulated irreversible steps in glycolysis How is each step regulated by allosteric molecules phosphorylation dephosphorylation and other mechanisms for example the translocation of GK What role do hormones play in those regulations Pay special attention to glucagon a Low glucagon decreased cAMP b Decreased PKA causes dephosphorylation PFK2 active favors form of F 2 6 BisP which activates PFK1 and increases glycolysis c Translocation of GK inhibits glucose phosphorylation increase of glucose release from cells 10 What does glycolysis consume and what does it produce a Consumes glucose b Produces pyruvate 2 ATP and 2 NADH 11 How is glycolysis connected to the TCA cycle a Pyruvate dehydrogenase complex pyruvate is converted to acetyl CoA 12 What s the TCA cycle for How does it connect to ETC a TCA cycle oxidizes acetyl CoA to produce substrates for fatty acid glucose and amino acids synthesis b NADH and FADH2 produced by the TCA cycle travels to the mitochondria to participate in ETC 13 What does TCA cycle consume and produce a Consumes fatty acids amino acids and acetyl CoA b 1 Acetyl CoA produces 3 NADH 1 FADH2 and 1 ATP 14 What does a cell do with the NADH made by glycolysis a Malate Aspartate Shuttle in brain and muscle NADH is oxidized to convert oxaloacetate to malate transported to mitochondrial membrane and converted back to oxaloacetate b Glycerol 3 Phosphate Shuttle in liver kidneys NADH is involved in the production of glycerol 3 phosphate which travels to inner membrane of mitochondria 1 NADH in the cytosol because 1 FADH2 in the mitochondria 15 Understand the concept of oxidation reduction and the flow of electrons a TCA cycle reduces NAD and FAD to NADH and FADH2 b ETC oxidizes NADH and FADH2 to NAD and FAD 16 How does ETC work to make ATP a Complex I NADH NAD hydrogen atom is pushed into the intermembrane space and the electron is passed onto the next complex b Complex II FADH2 FAD hydrogen is pushed into the intermembrane space and the electron is pushed to next complex c Hydrogen gradient outside membrane charges flow of electrons through final complex where ADP is converted to ATP 17 What s UCP1 for Why is it important a In the brown adipose tissue b Helps to generate heat in the mitochondria c Allows for fast substrate oxidation with low rate of ATP production 18 Know where the source of glucose is at different hours after fasting a Right after meal exogenous glucose b 5 hours after meal glycogenolysis c 24 hours after meal gluconeogenesis 19 Know the concept of GI What is it useful for What might influence it a Glycemic Index the intensity of changes in blood glucose levels due to carbohydrate intake b Useful for diabetics in determining what foods to eat c Influenced by the rate of glucose absorption into the intestine and the rate of glucose transport from the blood into the tissues 20 What organs and tissues are important for blood glucose regulation How does each tissue or organ contribute individually What hormones are involved What s the target organ for each hormone Focusing on glucagon what specific enzymes in what pathways are regulated by glucagon and how does that contribute to blood glucose control a Liver glycogenolysis and gluconeogenesis b Pancreas secretes glucagon and insulin i Insulin dephosphorylation of enzymes ii Glucagon increases cAMP phosphorylation of enzymes 1 Glucagon causes formation of cAMP which activates protein kinase A which causes release of glucose from glycogen c Glycogenolysis low glucose increases glucagon release then glucagon activates PKA which activates glycogenolysis 21 What is glycogen Why is it important How is glycogenolysis controlled by hormones What enzymes are involved and how is each enzyme regulated a Glycogen is the storage form of glucose b Glycogenolysis glucagon triggers cAMP which triggers the phosphorylation of glycogen phosphorylase kinase activation which releases glucose from glycogen 22 In the broad scheme of things what happens to hormone levels in the blood during fasting fed states and during exercise and fight or flight response What pathways are active inactive in each organ tissue in each condition Why How are they controlled At what enzyme a During fasting high glucagon levels low insulin levels