Key Area 7
(a) Metabolic pathways of cellular respiration
This marks the beginning of a larger key area focused on understanding cellular respiration. Take your time working the different activities until you feel confident for your in-class activities. Remember to bring specific questions with you to go over.
Something to Read...
Open the document below and read the mandatory course notes provided by SQA for this Key Area. You may wish to use your home learning time to copy these notes into a jotter or choose a digital presentation format that suits your learning style.
Something to look at...
During respiration, the breakdown of glucose provides chemical energy to produce ATP from ADP and inorganic phosphate. ATP molecules can later be broken down to release the stored energy for cellular functions, e.g. contraction of muscular tissue.
The diagram above shows the ultrastructure of a mitochondria. You will need to be aware of where the different stages of cellular respiration take place.
GLYCOLYSIS
Glycolysis is the breakdown of glucose to pyruvate in the cytoplasm.
ATP is required for initial phosphorylation of glucose and intermediates during the "Energy investment phase".
This leads to the generation of more ATP during energy pay-off stage and results in a net gain of ATP.
CITRIC ACID CYCLE
Occurs in the mitochondrial matrix
In aerobic conditions, pyruvate is broken down to an acetyl group that combines with coenzyme A forming acetyl coenzyme A.
In the citric acid cycle, the acetyl group from acetyl coenzyme A combines with oxaloacetate to form citrate.
During a series of enzyme-controlled steps, citrate is gradually converted back into oxaloacetate which results in the generation of ATP and release of carbon dioxide.
You are now ready for your in-class lesson on metabolic pathways of cellular respiration. Remember to bring any questions or queries with you.
You are now ready to move onto Key Area 7b on ATP synthesis.
