Cellular Respiration Flashcards
What is a catabolic pathway
Metabolic pathway that releases stored energy by breaking down complex molecules
What is a redox reaction
Reaction that involves reduction and oxidation
R - gain of electrons
O - loss of electrons
What is NAD and which form is oxidised and which form is reduced
A coenzyme that is a high energy electron carrier
O - NAD+
R - NADH
What are the 3 steps in cellular respiration and where do they occur
Glycolysis - Cytoplasm
Pyruvate oxidation and Kreb’s cycle - Mitochondrial matrix
Oxidative phosphorylation - Inner mitochondrial membrane
step 1 - What does Hexokinase (with 1 ATP) convert glucose into
Glucose-6-Phosphate
step 2 - Glucose-6-Phosphate is converted into one of its isomer - which one and what enzyme is used
Fructose-6-Phosphate
Phosphoglucoisomerase
step 3 - A phosphate group is then added to Fructose-6-phosphate using 1 ATP- what is made and what enzyme is used
Fructose-1,6-bisphosphate
Phosphofructokinase
step 4 - Fructose-1,6-bisphosphate is broken down into one of 2 2 3C molecules - What are these and what enzyme is used
Glyceraldehyde-3-phosphate (G3P)
Dihydroxyacetone phosphate (DHAP)
Aldolase
step 5 - G3P and DHAP can be converted between one another by what enzyme
Isomerase
step 6 - Each G3P is converted into 1,3-bisphosphoglycerate - what enzyme does this and what is produced
Triose phosphate dehydrogenase
NADH
step 7 - Phosphoglycerokinase breaks down 1,3-bisphosphoglycerate into what - what is produced
3-Phosphoglycerate
1 ATP
step 8 - The phosphate group is moved onto another carbon in 3-Phosphoglycerate to form what - what enzyme is used
2-Phosphoglycerate
Phosphoglyceromutase
step 9 - 2-phosphoglycerate is converted to Phosphoenol-pyruvate (PEP) - what enzyme does this and what is formed
Enolase
1 H2O
What are the net products formed from glycolysis from 1 glucose molecule
2 ATP
2 NADH
2 Pyruvate
2 H2O
step 10 - Outline the product formed from PEP, what enzyme is used and what else is produced
Pyruvate
Pyruvate Kinase
1 ATP
What multienzyme is used in Pyruvate oxidation
Pyruvate dehydrogenase complex
step 1 - What is removed from pyruvate to form a 2C fragment and what else is produced
Carboxyl group
CO2
step 2 - What is formed when the 2C fragment is oxidised and what else is produced
Acetate
NADH
step 3 - What happens to the acetate group
Coenzyme A is added to form Acetyl CoA
What are the net products formed from Pyruvate oxidation from 1 glucose molecule
2 Acetyl CoA
2 CO2
2 NADH
What are the net products formed from the Kreb’s cycle
4 CO2
2 ATP
6 NADH
2 FADH
What is substrate level phosphorylation
When an enzyme adds a phosphate group to ADP to form ATP
What are the three main steps in oxidative phosphorylation
ETC, Chemiosmosis and ATP synthase
Give a basic over view of the ETC (3)
Electrons are donated by carriers to ETC
Energy is lost each time they move from one protein complex to another
This energy is used to pump H+ ions from the matrix into the intermembrane space
What are the prosthetic groups on the innermembrane proteins also called
Redox centres
Where are NADH’s (2) and FADH’s electrons transferred to - what is the redox centre
NADH - Complex I - FMN then FE.S
FADH - Complex II - FE.s
What are the electrons passed to after complex I and II - why can it move within the membrane
Ubiquone / Coenzyme Q
It is a non-proteinous hydrophobic enzyme
What are complex III and IV made up of
Cytochromes
Where do the electrons end up at the end of the ETC
With oxygen to form water
How is the PMF created
As electrons move down the ETC the transmembrane complexes use the energy to pump H+ ions from the matric into the innermembrane space
Where do the H+ ions enter the ATP synthase
At the Stator
H+ then enters the rotor causing what to lead to what
A conformational change leading to the spinning of the rotor
What does the spinning rotor also cause to spin
The rod
What does the rod extend into and what does this activate
Catalytic knob
Catalytic sites to allow joining of ADP to Pi
Overall net gains of ATP for Cellular respiration
30 ATP
3 reasons why an exact number of ATP molecules cannot be stated
Phosphorylation and redox are not directly coupled - ATP won’t be a whole number
PMF can be used to drive other kinds of work
Yield will vary depending on proteins used to transport electrons
