Respiration Flashcards
Which two forms of energy are released by respiration?
Chemical (ATP) and heat energy
Draw and label a mitochondrion
Mitochondria consist of an outer and inner double membrane; intermembrane space; cristae; matrix; DNA and ribosomes.
Give the four stages of aerobic respiration
Glycolysis, the link reaction, the Krebs cycle, oxidative phosphorylation
Give the two stages of anaerobic respiration
Glycolysis, fermentation
Where does glycolysis happen?
The cytoplasm
What are the three products of glycolysis?
2 reduced NAD, a net of 2 ATP, 2 pyruvate
Why is NADH described as reduced NAD?
NAD has gained a hydrogen atom
What is the purpose of fermentation in anaerobic respiration?
To oxidise reduced NAD, so it can continue to be used in glycolysis
In anaerobic respiration, how many ATP are produced by fermentation?
0
What are the products of fermentation in animals?
Lactic Acid, NAD
What are the products of fermentation in plants?
Ethanol, CO2, NAD
What happens to lactic acid after fermentation?
It is transported to the liver and converted back into pyruvate
Where does the link reaction occur?
The mitochondrial matrix
What are the three products of the link reaction?
Acetyl coA, CO2, reduced NAD (x2 per glucose)
How many reduced NAD are produced in one turn of the Krebs cycle?
3
How many reduced FAD are produced in one turn of the Krebs cycle?
1
By which process is ATP produced in the Krebs cycle?
Substrate level phosphorylation
How many ATP are produced in one turn of the Krebs cycle?
1
Which enzyme removes hydrogen in glycolysis, the link reaction and the Krebs cycle?
Dehydrogenase
Which enzyme produces CO2 in the link reaction and the Krebs cycle?
Decarboxylase
Name three co-enzymes involved in respiration
NAD, FAD, acetyl coA
What is the energy yield in ATP for each reduced NAD in oxidative phosphorylation?
3
What is the energy yield in ATP for each reduced FAD in oxidative phosphorylation?
2
What is the final electron acceptor in respiration?
Oxygen
Why is the theoretical yield of 38 ATP from aerobic respiration not actually reached?
proton losses (leaky membranes) as well as the cost of moving pyruvate and ADP into the mitochondrial matrix
Explain endosymbiotic theory
Mitochondria and chloroplasts were once separate organisms that were absorbed by a larger cell through endocytosis.
At which stage do lipids enter respiration?
Lipids are broken down to glycerol and fatty acids. Glycerol enters as TP in glycolysis, fatty acids are broken into 2C fragments and enter the Krebs cycle as acetate.
At which stage do proteins enter respiration?
Proteins are hydrolysed to amino acids and deaminated in the liver, forming a keto acid and ammonia. The keto acid could enter glycolysis or the krebs cycle
