concept 9.4: during oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis

after glycolysis and the citric acid cycle what accounts for most of the energy extracted for food

NADH and FADH2

how do NADH and FADH2 power ATP synthesis

the two electron carriers donate electrons to the electron transport chain and power ATP synthesis via oxidative phosphorylation

where is the electron transport chain present in eukaryotes

in the inner membrane or the cristae of the mitochondrion

where is the electron transport chain located in prokaryotes

the electron transport chain is embedded in the plasma membrane

what makes up the electron transport chain

proteins that exist in multiprotein complexes

what happens to electrons as they go down the chain

the drop in free energy and are finally passed to O2 which forms H2O

process of electrons transferring to the electron transport chain

electrons are transferred from NADH in glycolysis or the citric acid cycle or from FADH2

what is cytochromes

a protein that electrons are passed through that have an iron atom

what is the final electron acceptor

O2

does the electron transport any ATP

does not directly any ATP

chemiosmosis

the energy coupling mechanism

what causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space

electron transfer in the electron transport chain

what happens after H+ is concentrated in the intermembrane space

H+ moves down its concentration gradient back across the membrane into the matrix

what is an example of chemiosmosis

the use of energy in a H+ gradient to drive cellular work

how many ATP molecules does ATP synthase generate

26-28 ATP

what is proton motive force

the energy stored in a H+ gradient across a membrane that couples the redox reactions of the electron transport chain to ATP synthesis

what happens at the end of the electron transport chain

FAD and NAD+ are reformed so they can be reused in the citric acid cycle

how is H2O formed at the end of the the electron transport chain

the electrons that leave at the end of the electron transport chain as 2 H+ and ½ O2 produce H2O

what is the sequence that energy flows in in cellular respiration

glucose to NADH to electron transport chain to proton motive force to ATP

how much ATP is made in stage 1

2 ATP

how much ATP is made in step 2

2 ATP

how much ATP is made in stage 3

26-28 ATP

what is the reasons why the exact number of ATP produced is not known

phosphorylation and the redox reactions are not directly coupled, ratio of NADH to ATP molecules is not a whole number

ATP yield varies depending on whether electrons are passed to NAD+ or FAD

the proton motive force is also used to drive other kinds of work

what do catabolic pathways do for cellular respiration

funnels electrons from many kinds of organic molecule into cellular respiration

what does glycolysis accept

wide range of carbohydrates

what must happen for proteins to feed glycolysis or the citric acid cycle

proteins must be digested to amino acids because only amino acids can be accepted

what is deamination

removal of the amino group- producing things like ammonia, urea and other wasre

what happens to fats

fats are digested to glycerol used in glycolysis and fatty acids

how are fatty acids proken down

by beta oxidation

what does the breaking down of fatty acids yield

acetyl CoA, NADH, FADH2

what can make more energy from its oxidation: fat or carbs

fat can produce more than twice as much ATP

what prevents wasteful production

feedback inhibition is most common

what happens when ATP concentration begins to drop

respiration speeds up if it drops and slows down if there is too much

what is the importance of phosphofructokinase

it can be inhibited by both ATP and citrate while AMP activates the enzyme