respiration Flashcards
Respiration equation
C6H12O6 + O2 –> CO2 +H2O
Main features of mitochondria
- outer membrane
- inner membrane
- intermembrane space
- crista
- matrix
the advantages of many cristae
- larger surface area
- provides more ATP
4 stages of aerobic respiration
- glycolysis
- link reaction
- krebs cycle
- Electron transport chain
2 ways ATP can be generated
- Substrate level phosphorylation
-oxidative phosphorylation
substrate level phosphorylation
ATP generated directly through respiration
occurs in glycolysis and Krebs cycle
oxidative phosphorylation
ATP generated from the chemical energy released when a reduced hydrogen carrier or coenzyme (NADH2 or FADH2) has been oxidised at the ETC.
Glycolysis process
- occurs in the cytoplasm
- glucose is phosphorylated via the hydrolysis of 2 ATP into 2xADP into phosphorylated. glucose
-Glucose phosphate is then split into 2x TP due to its instability
-Triose phosphate is then oxidised into pyruvate via the loss of a H+ via dehydrogenase enzyme
-this reduces NAD to NADH2
-produces ATP directly via substrate level phosphorylation
Link reaction process
- Pyruvate is actively transported into the matrix
- pyruvate to acetyl coenzyme A
- pyruvate is oxidised to acetate and the H+ ions are used to form NADH2
- a molecule of CO2 is lost via decarboxylation
- Coenzyme A fixes with acetate to form acetyl coenzyme A to transport the acetate to the Krebs cycle
krebs cycle
- series of enzyme controlled REDOX reactions that take place in the matrix of the mitochondria
-Acetyl CoA binds with 4C compound to form a 6C compound
-6C compound loses a C via CO2 and reduction of NAD
-5C compound is reduced to 4C compound via; the loss of CO2, synthesis of ATP, reduction of FAD, reduction of 2x NAD
Kreb Cycle Yields
-2x CO2 produced
-ATP produced directly by substrate level phosphorylation
-3x NADH
-1x FAD
1 glucose produces 2 acetyl CoA so krebs cycle occurs twice
how oxidation takes place in glycolysis and krebs cycle
-dehydrogenation
-by enzymes
-NADH formed
-In Krebs cycle FAD formed
Electron transport chain
- known as the chemiosmotic theory of oxidative phosphorylation
-NADH and FADH are oxidised so lose hydrogen
-electrons pass down a series of electron carries within the mitochondrial membranes in a. series of redox reactions
-electrons lose energy, some of it used to pump the H through the intermembrane space
-some energy lost as heat - H+ diffuse down a proton gradient into the matrix via ATP synthase enzymes
-enough energy is formed to produce ATP
-electrons and H+ recombine with oxygen gas to form water
-oxygen is the terminal electron acceptor
-without the removal of he H and electrons via oxygen there would be a backup of electrons along the ETC
-cellular respiration would come to a halt
Water is a waste product of aerobic respiration. Describe how water is formed at the end of aerobic respiration.
- oxygen is terminal
- combines with electrons and protons to form water
Describe how ATP is made in mitochondria (6)
-substrate level phosphorylation
-krebs cycle produces NADH
-electrons released from NADH
-electrons pass along carries through a series of redox reactions
-energy released
-protons pumped into intermembrane space
ADP +Pi —>ATP via ATP synthase
Describe the roles of co-enzyme and carrier proteins in the synthesis of ATP (6m)
-NADH electrons transferred from co-enzyme to co-enzyme
-energy released as electrons passed on
-energy used to synthesise ATP from ADP +Pi via ATP synthase
-H+ pumped into intermembrane space
-H+ diffuse back through ATP synthase enzyme
describe the events of oxidative phosphorylation
-NADH
-ETC on cristae
-H+ ions transferred from co-enzyme to co-enzyme
-releases energy as electrons passed on
-H+ pumped into the intermembrane space
-H+ flow back through enzyme
-energy used to synthesize ATP from ADP and Pi
Anaerobic respiration
-absence of oxygen
-link reaction, krebs cycle and electron transport chain stop as there is no oxygen to act as the terminal electron transporter
-glycolysis does not require oxygen and can continue in the absence of oxygen but NAD must be regenerated
-H from NADH is now accepted by pyruvate rather than passing through the ETC
-pyruvate is reduced to lactate in animals and ethanol in plants
explain how the amount of ATP is increased by reaction occurring inside a mitochondria
-oxidation of pyruvate
-substrate level production of ATP in krebs cycle
-production of NADH in the matrix of mitochondria
-electrons fed into ETC via phosphorylation on cristae linked to ATP production via ATP synthase
-electrons lose energy as passed along chain
-arranged in order of decreasing energy levels
Respirometers
-oxygen is used for aerobic respiration
-reduces the amount of oxygen therefore reducing the pressures
-solution of potassium hydroxide absorbs the CO2 released by the animal/plant
-ink solution moves from a high to low pressure along the graduated scale
-measure time taken
measure the rate of respiration
-measure the distance the ink/bubble moved
-over a fixed time
-volume of tube
