Respiration Flashcards
What evidence is there for evolution in relation to Respiration
All Respiration produces ATP
But different Respiratory substances
What cells respire
All eukaryota
What stages make up aerobic Respiration
Glycolysis
Link reaction
Krebs cycle
Electron transfer chain
What stages are in anaerobic Respiration
Glycolysis
Oxidation of reduced NAD
Describe glycosis
Glucose is phosphorylated to phosphorylated glucose using 2 ATP
Hydrolysis using water to produce triose phosphate
Oxidation to pyruvate using 2 ADP and 2 NAD per triose phosphate
Why must glucose be phosphorylated in glycolysis
Glucose isn’t very reactive
Phosphorylation allows glucose to be hydrolysed and oxidised
What is a coenzyme
Organic molecule need for some enzymes to function
Describe the link reaction
Pyruvate is oxidised to acetate
Requires 1NAD and produces 1 co2
Combined with coenzyme a to produce acetyl Coenzyme a
Where does glycolysis occur
Cytoplasm
Where does the link reaction occur
Mitochondrial matrix
How does pyruvate move from the cytoplasm to where the link reaction occurs
Active transport using carrier proteins
What is the function of the link reaction
To link glycolysis and Krebs cycle
Overall what is produced in glycolysis of one glucose
2 ATP
2 reduced NAD
2 pyruvate
Overall what is produced by the end of the link reaction for one glucose
2 ATP
2co2
2 acteyl coenzyme A
4 reduced NAD
Where does the Krebs cycle occur
In the mitochondrial matrix
Describe the Krebs cycle
Acetyl coa is combined with oxaloacetate to produce citrate and coenzyme A
A series of redox reactions producing 1 ATP 3 reduced NAD and 1 reduced FAD and 2 co2 coverts citrate to oxaloacetate
How is ATP produced in the Krebs cycle
Substrate level Phosphorylation
Overall what is produced up to the Krebs cycle for one glucose
4 ATP 10 reduced NAD 2 reduced FAD 6co2
What’s the importance of the Krebs cycle
Breaks down macro molecules into micro molecules (acetyl coa to co2)
Provides reduced coenzymes for the Etc
Regenerates oxaloacetate which would otherwise accumulate
Source of immediate compounds for manufacture of Amino acids and fatty acids
Wher is the energy released in the Etc stored
In electrons as potential energy
What does ETC stand for
Electron transfer chain
What is need for the ETC
Reduced Coenzymes
Cytochromes
Oxygen
ATP synthase
Describe how the ETC works
Reduced NAD releases electrons and protons
Electrons enter the ETC via Cytochromes. As electrons are passed along via redox reactions energy is released
Energy used to pump protons into intermembranal space where conc increase creating gradient
Protons diffuse down gradient back into matrix via ATP synthase using facilitated diffusion releasing energy required to synthesis ATP.
Protons and electrons recombine with oxygen to form water
What theory is used to explain the ETC
Chemiosmotic theory
By what method is ATP synthesised
Oxidative Phosphorylation
Explain the importance of oxygen in the ETC
Acts as terminal/ final electron acceptor
Wihtout it electrons would accumulate and reduced NAD would not be oxidised to NAD so links and Krebs stop working
Describe how the movement of electrons in the ETC releases energy
Each successive cytochrome is a little lower in energy
Electrons move down energy gradient
Energy released in small amounts preventing heat loss
What Respiratory substrates may be used
Lipids
Proteins
glucose
Describe how lipids are used as Respiratory substances
Lipid is hydrolysed into fatty acids and glycerol
Glycerol into triose phosphate into glycolysis
Fatty acids into acetate into link reaction
Why do lipids release more energy than glucose in Respiration.
Many H produced means many reduced coenzymes
Describe the Respiration of protein
Hydrolyse into Amino acids
Deaminiation to remove amine group
Converted into 3 carbon or 4/5 carbon chains
3c =pyruvate
4/5c = kreb cycle intermediates
Describe what conditions would cause anaerobic Respiration in plants mad fugi
Water logged fields
Describe anaerobic Respiration in plants and fungi
Glucose converted into pyruvate in glycolysis
Pyruvate reduced into ethanol and co2 oxidising the NAD to produced NAD for use in glycolysis
Describe conditions in which anaerobic Respiration would occur in animals
Extrenuous exercise
Describe anaerobic Respiration in animals
Glucose to pyruvate in glycolysis
Reduction of pyruvate to lactate via oxidation of reduced NAD to produce NAD for use in glycolysis
How many ATP molecules produced from 1 reduced NAD
3
How many ATP molecules produced from 1 reduced FAD
2
What advantage is there to anaerobic Respiration in muscles
Immediate energy source = lactate
PH levels restored
What are the consequences of anaerobic Respiration
Reduction of PH due to lactic acid
Denature of protein
Less efficient ATP production (rate of glycolysis increases to compensate)
What occurs after anaerobic Respiration once oxygen is reintroduced
Lactate converted into pyruvate or glucose and then glycogen
How do you measure the rate of Respiration
Rate of O2 uptake or co2 production
Using cappilary tube with dye.
What measurements are needed to record rate of Respiration
Distance travelled by dye
Diameter of tube
Time
Mass of organism
What causes the dye to move in calculating rate of Respiration
Reduced O2 volume decreases the pressure causing the dye to be drawn towards the organism
KOH needed to absorb co2 which would otherwise displace the O2
