1. Mesret Alemu & Urwa Imran
3.7 Cellular Respiration
Respiration is the production of ATP from organic molecules
- The controlled release of energy by enzymes from organic compounds
In order to keep generating efficient ATP, tissues which have high energy demand are rich in
mitochondria.
- ATP is not a stable long-term energy store. Long term stores include lipids and glycogen which
are metabolized through respiration
Glucose is a 6 carbon organic compound which is split into 2 pyruvate molecules in cytoplasm with small
yield of ATP
Pyruvate 3 carbons
Carbon dioxide 1 carbon
O carbons Water Oxygen
Phosphorus ATP
Aerobic respiration occurs in the presence of oxygen with a large yield of ATP, water is recycled in the
cell, carbon dioxide is released through gas exchange
Anaerobic respiration occurs in the absence of oxygen, reactions do not continue in mitochondria with
a low yield of ATP CO2 and ethanol and lactic acid are waste products
Hexokinase is an enzyme that splits glucose into pyruvate molecules ( glycolysis) this is reversed when
ATP levels return to normal