Cellular Energetics Flashcards
Where do cells get energy from?
Food molecules
What is the difference between autotrophs and heterotrophs?
Autotrophs metabolise by photosynthesis
Heterotrophs metabolise by cellular respiration
What is the process of breaking down food molecules called?
Catabolism
What is the word equation for metabolism?
Anabolism+catabolism= Metabolism
What are the 3 main stages of cellular respiration(aerobic)?
Glycolysis
The link reaction
Krebs cycle
What is the structure of ATP?
3 phosphate
Nitrogenous base
Ribose
What is ATP used for and how is it used for this?
Energy currency
Hydrolysis of high energy phosphate bonds
What is ATP converted to after releasing energy?
ADP
How many ATP’s are each NADH worth?
2.5
How many ATP’s are each FADH worth?
1.5
What happens in glycolysis?
Glucose goes to two molecules of pyruvate.
Happens in the cytoplasm
No oxygen needed
What happens in the link reaction?
Pyruvate transfers to acetyl CoA
In the matrix of the mitochondria
Requires oxygen
What happens in the Krebs Cycle?
Oxidation of acetyl group in CO2 with CoA release
In the matrix of mitochondria
Requires oxygen
What two processes happen in the oxidative phosphorylation?
Electron transport chain and chemiosmosis
What happens during oxidative phosphorylation?
High energy electrons pass through the complex in the matrix of the mitochondria
Requires oxygen
What are the 2 fates of pyruvate?
Fermentation and oxidation/ decarboxylation into acetyl-CoA
What are the two systems of fermentation pyruvate could go through?
Lactic fermentation
Ethanol fermentation
What happens in lactic fermentation?
Pyruvate is reduced to lactic acid
Occurs in the muscle cells in the cytoplasm
Absence of oxygen
No energy production
What is the word equation for lactic fermentation?
Glucose+2ADP +2Pi= 2lactate +2ATP +2H2O
What happens in ethanol fermentation?
Pyruvate is reduced to ethanol and CO2
Occurs in bacteria and yeast cells in the cytoplasm
No energy production
In the absence of oxygen
What is the word equation for ethanol fermentation?
Glucose+ 2ADP +2Pi=2 ethanol +2CO2 +2H2O +2ATP
What happens in the pyruvate oxidation/decarboxylation into Acetyl-CoA?
Links glycolysis to the Krebs cycle
Presence of oxygen
Pyruvate is pumped into the mitochondrial matrix
What is the word equation for the pyruvate oxidation/decarboxylation into Acetyl-CoA?
2 pyruvate + 2CoA+ 2NAD—> 2acetyl-CoA +2CO2+ 2NADH
How do we release fatty acids?
Lipases hydrolyse ester bonds to release fatty acids from triacylglycerol.
