C1.2 Cellular Respiration Flashcards
What is cellular respiration?
Cellular respiration is a system to produce energy in cells
What is the cellular respiration formula?
Oxygen+Glucose-carbon Dioxide & Water
6O2+C6H12O6->+6CO2+6H2O
What do cells need energy for?
-Synthesis of macromolecules: anabolic rxs, DNA replication
-Active transport: pumping of substances across a membrane
-Movement: muscle contraction
What is ATP
ATP is a nucleotide and it is the energy currency in cells
What does an ATP nucleotide consist of?
-3 Phosphate groups
-A ribose sugar
-An adenine base
What makes ATP an ideal energy currency?
-ATP is soluble in water so it can move freely in the cytoplasm
-ATP is chemically stable with a PH of 7
-ATP cannot pass freely through the phospholipid bilayer, preventing leakage
-ATP is easily regenerated
Conversion of ATP-> ADP
A-P-P-P->A-P-P P
-Hydrolysis
-Energy is released
Conversion of ADP -> ATP
A-P-P P->A-P-P-P
-Condensation
-Energy is required
What is the formula for ATP->ADP
ATP+H2O->ADP+phosphate+energy
What is the formula for ADP->ATP
ADP+phosphate+energy->ATP+H20
What happens when ATP is hydrolysed into ADP?
When ATP is hydrolysed into ADP, ernergy is released
During respiration what happens?
During respiration carbon compound are oxidised in order to release energy in the form of ATP
Aerobic respiration….
-Requires ATP
-Happens in the mitochondria
-Substrates are carbohydrates, lipids, amino acids
-Pyruvate->CO2+H2O
-Produces 34 molecules of ATP
-Purpose is for long lasting energy
Anaerobic respiration….
-Does not require ATP
-Happens in the cytoplasm
-Substrates are only carbohydrates
-Pyruvate->Lactic acid in a&h
-Pyruvate->Alcohol in yeast and some bacteria
-Produces 2 molecules of ATP
-Purpose is for short burst of energy
What is an electron carrier?
An electron carrier is something that gets easily oxidised and reduced
What is NAD?
NAD is the electron carrier in respiration
What is oxidation?
Oxidation is when a molecule looses an electron (energy)
What is reduction?
Reduction is when a molecule gains an electron (energy)
What is the equation of reduction?
NAD+2e+2H=Reduced NAD
What is REDOX?
REDOX is the process of oxidation and reduction happening simultaneously
What is glycolysis?
-Glycolysis is the first step in aerobic respiration
-Glycolysis does not require oxygen
-Glycolysis is the breaking down of a sugar
Where does glycolysis occur?
Glycolysis occurs in the cytoplasm
What is phosphorilation?
Phosphorylation is the adding of a phosphate group to a molecule in order to destabilise it
What is decarboxylation?
Decarboxylation is the removal of a carboxyl group from a molecule as a molecule of carbon dioxide
What are the outcomes of glycolysis?
-Net gain of 2ATP
-2 reduced NAD
-2 molecules of pyruvate
Step 1 of glycolysis….
-Phosphorylation
-Molecule of glucose gets phosphorylated twice
-ATP to ADP
Step 2 of glycolysis….
-Lysis
-Molecule of glucose gets split
-It gets phosphorylated once more not using ATP this time
Step 3 of glycolysis….
-Oxidation
-Two molecules get oxidised
-2 NAD to 2 reduced NAD
Step 4 of glycolysis….
-ATP formation
-4 ADP to 4 ATP using phosphates
-Net gain of 2 ATP
How does NAD needed for glycolysis to continue in anaerobic respiration regenerate?
-Pyruvate to Lactate and 2 reduced NAD to 2 NAD
What are the products humans produce during anaerobic respiration?
-Lactate
-2 ATP
What are the products humans produce during aerobic respiration?
-CO2
-H2O
-34 molecules of ATP
What are the products yeast produces during anaerobic respiration?
-CO2
-Ethanol
Where does the link rxn take place?
The link rxn takes place in the matrix of the mitochondria
What does the link rxn do?
The link rxn turns the 3 carbon molecules of Pyruvate into a 2 carbon molecule acetyl coA
What is the first step in the link rxn?
The pyruvate molecule gets decarboxylated making it a 2 carbon molecule
What is the second step in the link rxn?
REDOX, pyruvate gets oxidised and NAD becomes reduced
What is the third step in the link rxn?
CoA gets attached
Draw the link rxn….
….
Where does the Krebs cycle take place?
The Krebs cycle takes place in the matrix of the mitochondria
What does the Krebs cycle do?
The Krebs cycle oxidises and decarboxylates the acetyl coA
What are the outcomes of the Krebs cycle?
-Reduced NAD
-Reduced FAD
-ATP
What is the first step in the Krebs cycle?
C4 attaches to acetyl coA
What is the second step in the Krebs cycle?
-Enzyme coA gets removed
What is the third step in the Krebs cycle?
-C6 gets decarboxylated
-REDOX, NAD picks up electrons & becomes reduced NAD
What is the fourth step in the Krebs cycle?
-C5 gets decarboxylated
-REDOX, NAD picks up electrons and becomes reduced NAD
What is the fifth step in the Krebs cycle?
- residual electrons allow for further REDOX
-NAD to reduced NAD
-FAD to reduced FAD
-ADP to ATP
Where does the ETC take place?
The ETC takes place in the intermembrane of the mitochondria
What does the ETC do?
The ETC generates ATP
What is embedded in the inner membrane of the mitochondria?
Electron carriers, proteins that are easily reduced and oxidised
Explain the role of the ETC….
-The ETC regenerates ATP
-The ETC receives electrons from oxidation rxs
-The ETC receives electrons from reduced NAD and reduced FAD
-Energy released as electrons gets passed on from carrier to carrier
-Protons get pumped into the intermembrane space, creating a high concentration of protons
-Protons pass through ATP synthase back into the matrix
-Flow of protons allow for ATP generation
What is the first step in the ETC?
-Reduced NAD delivers electrons to the first protein
-Reduced NAD becomes oxidised, releasing energy
-Energy is used to pump protons across the membrane from the matrix into the intermembrane space
What is the second step in the ETC?
-Electron carrier apsses electrons to next protein, simultaneously picking up electrons from reduced FAD
-Reduced FAD gets oxidised releasing energy
-Energy is used to pump protons across the membrane from the matrix into the intermembrane space
What is the third step in the ETC?
-Electron carrier passes electrons to the next protein simultaneously picking up electrons from reduced NAD
-Reduced NAD gets oxidised, releasing energy
-Energy is used to pump protons across the membrane from the matrix into the intermembrane space
What is the fourth step in the ETC?
Chemiosmosis, protons move from high concentration to low concentration through ATP synthase converting ADP into ATP
What is the fifth step in the ETC?
Electrons on the last protein get picked up by O2 as well as protons on the matrix making H2O
What is the difference between lipids and carbs?
Lipids release more energy than carbs
