Glycolysis and metabolism Flashcards
What is a metabolite?
- An intermediate or product of metabolism
- usually small molecules
What is the function of metabolites?
- fuel
- structure
- signalling
- regulatory effects on enzymes
- defence
- interactions with other organisms
How are metabolites linked?
Between metabolic reactions
What are metabolic reactions?
The life-sustaining enzyme-catalysed reactions that allow organisms to grow, reproduce, respond to changes in the environment and maintain structure
What is a metabolic pathway?
a sequence of chemical reactions undergone by a compound or class of compounds in a living organism (the product of one enzyme acts as the substrate for the next enzyme)
Is glucose taken in from the environment or synthesised in the body?
Glucose can be absorbed through the diet or created in the body by gluconeogenesis
What is typically thought of as the universal energy provider?
Glycolysis
How to you convert glycogen to glucose?
Glycogenolysis
How do you convert glucose to Glycogen?
Glycogenesis
How do you convert glucose to pyruvate?
Glycolysis
How do you convert pyruvate to glucose?
Gluconeogenesis
How do you convert pyruvate to lactate or ethanol?
Fermentation by anaerobic respiration
What do you convert pyruvate to ATP?
TCA cycle and electron transport chain
Where does glycolysis occur?
cytoplasm
What are the two phases of glycolysis?
ATP consumption and ATP production
In glycolysis what does one glucose molecule get converted to using ATP?
1 x glucose-6-phosphate
What is the net production from glycolysis per molecule of glucose?
2x ATP
2x NADH
2x Pyruvate
What is anaerobic metabolism?
Incomplete oxidation of glucose to lactate and hence less energy is produced
What is aerobic metabolism?
Aerobic respiration allows for the complete oxidation of glucose and produces more ATP
What are the stages of glycolysis? (in general)
1 x glucose —> 1 x glucose-6-phosphate (-ATP)
1 x glucose-6-phosphate —> 1x fructose-6-phosphate (-ATP)
1x fructose-6-phosphate—> EITHER 2x dihydroxyactetone phosphate OR 2x glyceraldehyde-3-phosphate
2x glyceraldehyde-3-phosphate —> 2x 1,3-diphosphoglycerate (2NAD+–> 2NADH)
2x1,3-diphosphoglyverate—> 2x 3-phosphoglycerate (2ADP–>2ATP)
2x 3-phosphoglycerate —> 2x 2-phosphoglycerate
2x 2-phosphoglycerate —> 2x phosphoenolpyruvate
2x phosphoenolpyruvate —> 2x pyruvate (2ADP –> 2ATP)
How is glucose imported into mammalian cells?
Sodium monosaccharide co-transport system using SGLTs
Sodium independent facilitated diffusion using GLUT transporters
What is Hexokinase?
Enzyme used in the first step of glycolysis to phosphorylate glucose at the 6th carbon creating glucose-6-phosphate
What is the purpose of glucose phosphorylation?
Traps glucose in cells preventing the molecule leaving through GLUT2
Destabilises glucose so further metabolic reactions can be carried out.
What is the importance of cleavage from a 6C molecule to a 3C molecule?
Allows for the production of 2 molecules of pyruvate.