Respiration M5 Flashcards
Define Aerobic respiration
The complete breakdown of glucose inside cells in the presence of oxygen to to yield energy (in the form of 32 ATP)
Define Anaerobic respiration
The breakdown of glucose inside the cells in the absence of oxygen to yield energy (in the form of 2 ATP)
Why does aerobic respiration yield fewer molecules of ATP than the theoretical maximum?
1, Some of the ATP is used to actively transport pyruvate to mitochondria. 2. Some ATP used to actively transport H+ ions from reduced NAD. 3. Some energy lost on electron transport chain , released via heat
Compare anaerobic respiration in animals and yeast cells.
ANIMALS - pyruvate reduced to lactate, can be reversed as no atoms are lost, lactate dehydrogenase available to reverse reaction. YEAST - pyruvate converted to ethanol and CO2 in two steps, cannot be reversed as CO2 is lost, decarboxylase enzyme cannot reverse the reaction.
Reasons why anaerobic respiration produces less ATP than aerobic respiration.
- glucose –> pyruvate (only glycolysis occurs in anaerobic) 3. substrate level phosphorylation only produces 2 ATP 4. oxygen is final electron acceptor. 5. pyruvate used to regenerate NAD for glycolysis to continue. 6. chemiosmosis and oxidative phosphorylation does not occur, which accounts for 28 ATP in aerobic reparation.
What is a respiratory quotient
The ratio of the amount of CO2 produced and O2 consumed.
Energy value and Respiratory quotient of lipids
0.7 and 39
Energy value and Respiratory quotient of proteins
0.9 and 17
Energy value and Respiratory quotient of carbohydrates
1 and 16
Respiratory substrate
A respiratory substrate is a molecule that energy can be released from to synthesise ATP.
How many ATP made from one turn in Krebs cycle
1
How many pyruvates does glucose produce
2
