| Where does glycolysis take place | Cytoplasm |
| What are the irreversible reactions in glycolysis | Phosphorylation of glucose into G-6-P
Phosphyraltion of F-6-P into 1,6 fructose bisphosphate
Substrate level phosphoryation of ADP into ATP leading to formation of pyruvate
These are irreversible due to having large negative delta G values |
| What are the products of glycolysis using one molecule of glucose | 4 ATP ( +2 net ) , 2 NADH, 2 Pyruvate |
| What are some uses of DHAP? | Can be converted into glycerol-3-phophate which is important in phospholipid and triglyceride synthesis
DHAP is produced in adipose tissue and liver
Hence glycolysis is needed for lipid synthesis |
| What are some uses of 1,3 bisphosphoglycerate | Can be converted into 2,3 BPG
Important regulator of oxygen affinity in haemoglobin in RBCs |
| What are some regulators of glycolysis | Hexokinase is a good target
Phosphofructokinase is inhibited allosterically by ATP in muscle and glucagon in liver
Pyruvate kinase in inhibited by glucagon and activated by insulin |
| What is lactate dehydrogenase reaction needed for? | The regneration of NAD+ from NADH, it converts pyruvate into lactate when there is no available oxygen
lactate is metabolised in the liver, heart and kidney |
| Galactose metabolism? | Galactose is phosphorylated using ATP ( galactokinase ) then converted into glucose-1-phosphate using the UDP-glucose which can then enter glycolysis for energy |
| Galactosaemia types and features | 2 types - classical ( GALT deficieny ) and non-classical ( galactokinase deficiency )
Classical - 1-P uridyl transferase enzyme deficiency leading to accumulation of galactose-1-phosphate --> liver and brain damage
Both leads to accumulation of galactose and galactose-1-phosphate in tissues leading to the formation of galactitol and cataracts
Also depletes the tissues NADPH stores |
| Fructose intolerance is caused by what | Deficiency of aldolase enzyme
Leads to accumulation of F-1-P in the liver leading to liver damage and hypoglycaemia
Vomiting , Nausea and Pain |
| What is the Pentose Pathway | It is a two stage pathway
Decarboxyation of G-6-P by glucose-6-phosphate dehydrogenase to form 2NADPH, CO2, 2H+ and a pentose sugar
After that it is rearrangement of intermediates to form Glyceraldhyde-3-P to enter glycolysis |
| Why is the Pentose Pathway important? | For regeneration of NADPH, to protect the -SH bonds in RBC since they are prone to oxidative damage leading to the formation of disulfide bonds leading to the RBC becoming more rigid and the formation of Heinz bodies
Production of C5 sugars for nucleic acid formation |
| How does Lactose intolerance happen | Loss/reduced lactase due to reduced expression of the LCT gene
Leads to accumulation of lactose in the colon which draws out water from the body leading to diarrheoa
Also colonic bacteria ferment lactose leading to the formation of gasses such as H2/CO2 and CH4 |
| What are some investigations for lactose intolerance | H2 breath test and stool acidity test |
| Essential Fructosuria | Basically due to deficiency of fructokinase
No symptoms but just increase fructose in urine |
