13.4 Respiration Flashcards
What is the word equation for respiration?
Glucose + oxygen –> Carbon dioxide + Water + ATP
What is the number equation for respiration?
C6H12 + 6O2 –> 6CO2 + 6H2O + ATP
Why is ATP useful?
ATP can be dephosphorylated and phosphorylated again many times
It is a single step process
It is an immediate source of energy
Provides small packets of energy
Cannot pass out of cells
How is a mitochondria adapted to its function?
Large surface area - it has folded Cristae for more ETC
Matrix full of ribosomes and enzymes to complete the Krebs cycle
Small inter membrane space to build up a proton gradient quickly
Name the 4 process’ of aerobic respiration
Glycolysis
Link reaction
Kreb’s cycle
Electron transport chain
Where does glycolysis take place?
Cytoplasm of the cell
Where does the link reaction take place?
Matrix of the mitochondria
Where does the Kreb’s cycle take place?
Matrix of the mitochondria
Where does the electron transport chain occur?
Intermembrane space
What are the two ways that ATP can be generated?
Substrate level phosphorylation
Oxidation phosphorylation
What is substrate level phosphorylation and where does it occur?
When ATP is generated directly through energy released via respiration
Glycolysis and the Krebs cycle
What is oxidative phosphorylation and where does it occur?
When ATP is generated from the chemical energy released when a reduced hydrogen carrier our coenzyme has been oxidised
Electron transport chain
What is produced in glycolysis?
2 net ATP molecules
2 reduced NAP molecules
2 pyuruvate molecules
Describe glycolysis
Glucose is phosphorylated twice in order to produce phosphorylated glucose. The phosphate molecules are provided by the hydrolysis of ATP.
The unstable glucose molecules splits up into 2 3 carbon compounds, triode phosphate.
each trios phosphate is then oxidised too pyruvate which involves the loss of a hydrogen via dehydrogenase.
This reduces NAD to reduced NAD.
The energy produced at this step also 1 ATP molecule via substrate level phosphorylation
Describe the link reaction
Pyruvate is actively transported into the matrix of the mitochondria.
Pyruvate is oxidised to acetate, this produces one carbon dioxide molecule and reduces an NAD molecule
Coenzyme A combines with the acetate to form acetyl coenzyme A
What is produced in the link reaction?
Reduced NAD
CO2
Acetyl coenzyme A
Describe the Krebs cycle
Acetyl coenzyme A combines with a 4 carbon compound to produce a 6 carbon compound
The 6 carbon compound loses a CO2 molecule and a hydrogen which reduced NAD
The 5 carbon compound then loses another carbon dioxide molecule and 2 hydrogen molecules, 2 NAD and an FAD are reduced
Enough energy is also produced to provide 1 molecule of ATP
The cycle continues
What is produced in the Krebs cycle?
2 CO2 molecules
3 reduced NAD
Reduced FAD
1 molecule of ATP via substrate level phosphoprylation
How many times does the kerbs cycle occur per molecule of glucose?
Twice
Describe the electron transfer chain
The reduced FAD and NAD are oxidised by losing hydrogen.
The electrons from the hydrogen atom are passed down a series of electron carriers, losing energy in a series of redox reactions.
The energy is then used to pump the protons through the inner membrane into the inter membrane space.
Some of the energy is lost through heat.
The H+ ions diffuse down a proton gradient across the inner membrane via ATP synthase, producing ATP
The electrons recombine with the hydrogens to form water.
Oxygen is the final electron acceptor.
Water is a waste product in aerobic respiration, describe how it is formed
Oxygen is the final electron acceptor
The oxygen, electrons and hydrogen ions recombine to form water
Describe how ATP is made in the mitochondria
- Substrate level phosphorylation produces ATP in the Krebs cycle
- Krebs cycle and link reaction produces reduced NAD and FAD
- The electrons released from the reduced FAD and NAD pass along a series of carrier proteins through a series of redox reactions
- Energy is released and protons are pumped into the inter membrane space
- ATP is formed from ADP and Pi from the protons diffusing through the ATP synthase
Describe the roles of the coenzyme and carrier proteins in the synthesis of ATP
- Reduced NAD and FAD
- Electrons transferred from the coenzyme to coenzyme via a series of redox reactions
- Energy released as electrons passed along 0
- The energy is used to synthesise ATP ATP from ADP and Pi using ATP synthase
- H+ ions pumped into the inter membrane space
- H+ ions diffuse back through ATP synthase
Describe how oxidation takes place in glycolysis and the Krebs cycle
- Removal of hydrogen any dehydrogenase
- H accepted by NAD and forms reduced NAD
- In the Krebs cycle FAD is reduced too
What isanaerobic respiration.
Respiration in the absence of oxygen
