Term
| Why do we need to make glucose? |
|
Definition
| Brain and Erythrocyte metabolism |
|
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Term
| When do we need to make new glucose? |
|
Definition
| During and after exercise and during stravation |
|
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Term
|
Definition
|
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Term
| Where does gluconeogenesis occur? |
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Definition
|
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Term
| What are the three precursers for gluconeogenesis? |
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Definition
| Glycerol, amino acids and lactate? |
|
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Term
| What is the glycerol the precurser for? |
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Definition
|
|
Term
| What are amino acids the precursers for? |
|
Definition
| Pyruvate and Oxaloacetate |
|
|
Term
| What is lactate the precurser for? |
|
Definition
|
|
Term
|
Definition
| The combination of gluconeogensis and glycolysis between the liver and the muscles |
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Term
| Why is gluconeogenesis not just the reverse of glycolysis? |
|
Definition
| Some steps are irreversible |
|
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Term
| What makes the steps in glycolysis irreversible? |
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Definition
| They have a high delta G value and so require a lot of energy in the reverse direction |
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Term
| How is the irreversible step that converts PEP to Pyruvate reversed? |
|
Definition
| Pyruvate is converted to Oxaloacetate ad then PEP |
|
|
Term
| What does pyrivate carboxylase do? |
|
Definition
| Adds a phosphate group from ATPand a carbon dioxide group to convert pyruvate to oxaloacetate |
|
|
Term
| What does PEP carboxykinase do? |
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Definition
| Adds a phosphate group from GTP and then decarboxylates Oxaloacetate to form PEP |
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Term
| How is the irreversible step that converts Fructose-6-phosphate to fructose-1,6-bisphosphate reversed? |
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Definition
| By the enzyme fructose-1,6-bisphosphatase |
|
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Term
| What does the enzyme fructose-1,6-bisphosphatase do? |
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Definition
| Hydrolyses a phosphate group to convert fructose-1,6-bisphosphate into fructose-6-phosphate |
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Term
| How is the irreversible step that converts glucose to glucose-6-phophate reversed? |
|
Definition
| By the enzyme glucose-6-phosphotase |
|
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Term
| What does the enzyme glucose-6-phosphotase do? |
|
Definition
| Hydrolyse a phosphate group to convert glucose-6-phosphate to glucose |
|
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Term
| What happened to PEPCK-C genetically engineered mice? |
|
Definition
| Ate 60% more but had 10% body fat, had increased mitochondria and lived an extra 2 years. |
|
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Term
| Where does gluconeogenesis occur is the cell? |
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Definition
|
|
Term
| What is the problem with gluconeogenesis occurring in the cell? |
|
Definition
| Pyruvate carboxylase is located in the mitochondrial matrix and the matrix wall is impermeable to oxaloacetate |
|
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Term
| How is the gluconeogenesis problem resolved? |
|
Definition
| Pyruvate enters the matrix, decarboxylated to oxaloacetate, dehydrogenated to maltate. the maltate then leaves the mitochondria and is converted back into oxaloacetate |
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|
Term
| What two things activate phosphofructokinase? |
|
Definition
| Presence of fructose-6-phosphate and AMP |
|
|
Term
| Waht two things inhibit phosphofructokinase? |
|
Definition
| Presence of citrate and ATP |
|
|
Term
| What activates fructose-1,6-bisphosphotase? |
|
Definition
|
|
Term
| What two things inhibit fructose-1,6-bisphosphotase? |
|
Definition
| Presence of fructose-6-phosphate and AMP |
|
|
Term
| What activates pyruvate kinase? |
|
Definition
| Presence of fructose-1,6-bisphosphate |
|
|
Term
| What inhibits pyruate kinase? |
|
Definition
|
|
Term
| What activates pyruvate carboxylase? |
|
Definition
|
|
Term
| What inhibits pyruvate carboxylase? |
|
Definition
|
|
Term
| What inhibits PEP carboxylase? |
|
Definition
|
|
Term
| What affect does insulin have on gluconeogenesis? |
|
Definition
|
|
Term
| What affect does glucagon have on gluconeogenesis? |
|
Definition
| Increases gluconeogenesis |
|
|
Term
| Where does the ATP ad GTP required for gluconeogenesis come from? |
|
Definition
| Standard reqpiration and oxidation of fats |
|
|
Term
| What percentage of muscles is glycogen? |
|
Definition
|
|
Term
| What percentage of liver is glycogen? |
|
Definition
|
|
Term
| What is the purpose of the glycogen store n muscles? |
|
Definition
| Release to glucose-6-phosphate for respiration |
|
|
Term
| What is the purpose of the glycogen store in the livers? |
|
Definition
| Controlling blood glucose levels |
|
|
Term
| Which energy molecules releases the most energy? |
|
Definition
|
|
Term
| Why use glycogen as main energy store and not fats? |
|
Definition
| Glucose can be hydrolysed anaerobically and is hydrolysed quicker |
|
|
Term
| What are the four stages of glycogen synthesis? |
|
Definition
| Diversion, Activation, Polymerisation, Branching |
|
|
Term
| What happens in the diversion stage of glycogen synthesis? |
|
Definition
| Phosphogluco-mutase converts glucose-6-phosphate into glucose-1-phosphate |
|
|
Term
| What does phosphogluco-mutase do? |
|
Definition
| Rearranges glucose-6-phosphate to glucose-1-phosphate |
|
|
Term
| What happens in the activation stage of glycogen synthesis? |
|
Definition
| UDP-glucose pyrophosphorylase activates the glucose unit by converting glucose-1-phosphate to UDP-glucose |
|
|
Term
| What does UDP-glucose pyophosphorylase do? |
|
Definition
| Adds a UDP unit converting glucose-1-phosphate to UDP-glucose |
|
|
Term
| What happens during the polymerisation stage of glycogen synthesis? |
|
Definition
| Glycogen synthase adds UDP-glucose to another molecules of glucose connected by a 1,4-glycosidic bond |
|
|
Term
| What does glycogen synthase do? |
|
Definition
| Converts UDP-glucose into glycogen by creating a 1,4-glycosidic bond |
|
|
Term
| What happens during the branching stage of glycogen synthesis? |
|
Definition
| Branching enzyme adds UDP-glucose to another molecules of glucose connected by a 1,6-glycosidic bond |
|
|
Term
| What does the branching enzyme do? |
|
Definition
| Converts UDP-glucose into glycogen by creating a 1,6-glycosidic bond |
|
|
Term
| What are the three steps of glycogenolysis? |
|
Definition
| Phosphorolysis, Debranching and Recovery |
|
|
Term
| What is the fourth step of glycogenolysis that only occurs in the liver? |
|
Definition
|
|
Term
| What happens during the phosphorolysis step of glycogenolysis? |
|
Definition
| Glycogen phosphorylase removes the terminal glucose residues by breking the 1,4-glycosidic bonds |
|
|
Term
| What does glycogen phosphorylase do? |
|
Definition
| Adds a phosphate group to a terminal glucose residue to break the 1,4-glycosidic bond to produce glucose-1-phosphate |
|
|
Term
| What happens during the debranching stage of glycogenolysis? |
|
Definition
| Removal of the 1,6-glycosidic bonds of glycogen to form more glucose-1-phosphate |
|
|
Term
| What does the enzyme transferase do? |
|
Definition
| Moves the branch (minus the 1,6-glycosidic glucose) to the main branch |
|
|
Term
| What does a-1,6-glycosidase do? |
|
Definition
| Hydrolyses the 1,6-glycosidic bonds to release the final glucose of the branch |
|
|
Term
| What happens during the recovery stage of glycogenolysis? |
|
Definition
| Glucose-1-phosphate is converted to glucose-6-phosphate? |
|
|
Term
| What happens in the release stage of glycogenolysis? |
|
Definition
| Conversion of glucose-g-phosphate to glucose for blood release |
|
|
Term
| Where does the conversion to glucose-6-phosphate occur? |
|
Definition
| In the endoplasmic reticulum |
|
|
Term
| What happens in type one Von Gierke Disease? |
|
Definition
| Faulty glucose-6phosphotase creates too much glycogen which enlarges the liver |
|
|
Term
| What happens in type three Cori disease? |
|
Definition
| Faulty debranching enzyme creates lots of glycogen with short branches which enlarges the liver |
|
|
Term
| What happens in type five McArdle disease? |
|
Definition
| Faulty glycogen phosphorylase creates an abnormal amount of glycogen which increases the number of muscle cramps |
|
|
Term
| During exercise the rate of glycolysis _______? |
|
Definition
|
|
Term
| At rest the rate of glycolysis _______? |
|
Definition
|
|
Term
| During exercise the rate of gluconeogenesis _______? |
|
Definition
|
|
Term
| During exercise the rate of glycogen synthesis _______? |
|
Definition
|
|
Term
| During exercise the rate of glycogenolysis _______? |
|
Definition
|
|
Term
| At rest the rate of gluconeogenesis _______? |
|
Definition
|
|
Term
| At rest the rate of glycogen synthesis _______? |
|
Definition
|
|
Term
| At rest the rate of glycogenlysis _______? |
|
Definition
|
|
Term
| After a meal the rate of glycolysis _______? |
|
Definition
|
|
Term
| After a meal the rate of gluconeogenesis _______? |
|
Definition
|
|
Term
| After a meal the rate of glycogen synthesis _______? |
|
Definition
|
|
Term
| After a meal the rate of glycogenolysis _______? |
|
Definition
|
|
Term
| During fasting the rate of gluconeogenesis _______? |
|
Definition
|
|
Term
| During fasting the rate of glycolysis _______? |
|
Definition
|
|
Term
| During fasting the rate of glycogen synthesis _______? |
|
Definition
|
|
Term
| During fasting the rate of glycogenolysis _______? |
|
Definition
|
|
Term
| Which three key hormones affect glycogen metabolism? |
|
Definition
| Inculin, glucagon and epinephrine |
|
|
Term
| What affect does glucagon have on the glucose metabolism pathways? |
|
Definition
| Increase of glycogenolysis, gluconeogenesis and inhibiton of glycogen synthesis and glycolysis |
|
|
Term
| What affect does insulin have on the glucose metabolism pathways? |
|
Definition
| Inhibition of glycogenolysis, gluconeogenesis and increase of glycogen synthesis and glycolysis |
|
|
Term
| Which GLUT transporter mediates secretion of insulin? |
|
Definition
|
|
Term
| Outline the mechanism that releases insulin? |
|
Definition
1)GLUT2 transporter protein transports glucose into a beta-cell
2)Glucose undergoes glycolysis to produce ATP
3)Build up of ATP causes insulin containing vesicles to fuse with the membrane and be released into the blood |
|
|
Term
| Which GLUT transporter is put into the membrane of cells to take up glucose in a response to insulin? |
|
Definition
|
|
Term
| What causes Type I diabetes? |
|
Definition
| Autoimmune response that destroys beta-cells |
|
|
Term
| What is the treatment given for patients with Type I diabetes? |
|
Definition
|
|
Term
| What causes Type II diabetes? |
|
Definition
| Insulin receptors become ineffecient |
|
|
Term
| What is the treatment for a patient with type II diabetes? |
|
Definition
|
|
Term
|
Definition
| Glucose is not reabsorbed at the kideny causing large amount of water to enter the collecting duct and so large volumes of urine are excreted |
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