THE ETC LESOON 5

Question 1

whats the recap

Answer 1

every carbon atom in a moelcule of glucose has been converted to carbon dioxide
very few atp molecules have been produce
most of the energy is still in the form of reduced nadh and fadh2
the majority of atp molecuels produced furing aerboic respiration comes from oxidative phosphorylation

Question 2

oxidative phosphorylation

Answer 2

oxidative phosphorylation is a process that couples the oxidaition of nadh and fadh2 by the etc.
with the synthesis of atp by phosphorylation of adp
at the end of this process, oxygen acts as the electron acceptor and is converted to water.

Question 3

the etc

Answer 3

it is a series of electron carriers and proteins that are embedded in the inner membrane of the mitohondrion.
electrons donated by nadh and fadh2 are transported through this chain, providing energy needed for oxidative phosphorylation

Question 4

what happens during it

Answer 4

the etc accepts the electrons from nadh and fadh2 and passes them from one carrier molecule to the next in a series of successive reduction and oxidation reactions
the electrons release energy as they fall down from the etc from one carrier to another. the 3 major complexes of the etc use this energy to ACTIVELY pump hydrogen ins out of the matrix into the intermemebrane space, this creating a hydrogen ion gratient.
- nadh gives its electrons in the first complex, and fadh2 gives its electrons to the second, skipping the first.

Question 5

what else happens

Answer 5

the 2 electrons from nahd provide enough energy to pump 6 H+ from the matrix into the intermemerane space.
- the 2 electrons from fadh2 provide enough energy to pump 4 h+ from the matrix into the intermemebrane space.
- the final eolectron acceptor is oxygen, which aslo combines with 2 hydrogen ions(H+) to produce water.
***The ransfer of electrons to oxygen removes them from the etc and allows more electrons to flow down the chain
this prevents the pile up of electrons and the etc can continue function making more atp.

Question 6

continue making atp

Answer 6

the hydrogen ions are restricted from flowing back in matrix. the electrical Ep(h+ gradient) is converted to chemical Ep(ATP) when the hydrogen ions flow thru complexes called atp synthases by facillitated diffusion.
(the energy released when h+ moves alng their concentration gradient is used to combine ADP+Pi)
in he final step of chemiosmosis, atp is produced from adp and pi by the energy generated in atp synthases.

Question 7

making atp

Answer 7

the energy released from the falling electrons is used to pump H+ ions and estalish an electrochemical gradient, also called a hydrogen ion gradient.
chemiosmosis is a process that uses energy in a hydrogen ion gradient across the inner mitochondrial membrane to drive the phosphorylation of adp to form atp

Question 8

HOW mUCH ATP PRODUCED

Answer 8

every time 2 h+ re enters the matrix thru the atp synthase complex, 1 atp is made
therefore, 2 H+ = 1ATP
- recall:
each nadh provides the energy to pump 6h+ and therefore, 3 atp is made.
each fadh2 provides the energy to pump 4h+ therefore 2 atp is made
total from oxidative phosphorylation>
8nadh x 3 atp = 24 atp
4fadh2 x 2 atp = 8 atp
24 atp + 8 atp = 32 atp

Question 9

aerobic respiration summary

Answer 9

c6h12o6 + 6co2 –> 6co2 + 6h2o = 36 atp