Pathways that Harvest and Store Chemical Energy

_____ = the gain of one or more electrons by a compound

reduction

____ = the loss of one or more electrons from a compound

oxidation

when a molecule loses one or more hydrogen atoms, it becomes ____

oxidized

when a molecules gains one or more hydrogen atoms, it becomes ____

reduced

going from more reduced to a more oxidized state ___ energy

releases

cells commonly use ____ and ____ as electron carriers to temporarily trap energy released during breakdown of foods

NADH; FADH2

being reduced ___ energy

absorbs

being oxidized ___ energy

releases

glucose oxidation can be ____ or ___

complete; partial

aerobic oxidation (respiration) is ____ oxidation

complete

fermentation is ____ oxidation

incomplete

the overall reaction for aerobic oxidation is ___ molecule of glucose and ___ molecules of O2 react to give ____ molecules of CO2 and ___ molecules of water

1; 6; 6; 6

the three major pathways of aerobic oxidation are _____, ____ ____ and the ____ ____ ___

glycolysis; pyruvate oxidation; citric acid cycle

glycolysis occurs in the ____

cytoplasm

pyruvate oxidation and the citric acid cycle occur in the ____ ___

mitochondrial matrix

electron transport/atp synthesis happens in the ___ ____ ___

inner mitochondrial membrane

the net products of glycolysis are ___ molecules of _____, ___ molecules of ___ and ___ molecules of ___ (per one molecule of glucose)

2; pyruvate; 2; atp; 2; NADH

each pyruvate has ____ carbon atoms

3

pyruvate oxidation produces one ____, one ____ and one ____ per pyruvate molecule; acetate is then bound to ____ ___ to form ____ ___

CO2; acetate; NADH; coenzyme A; acetyl CoA

____ ____ is the first time that CO2 is released

pyruvate oxidation

each acetate has ___ carbon atoms

2

the citric acid cycle operates ____ for every glucose molecule that enters glycolysis

twice

the citric acid cycle starts with ___ ___; the ____ group is fully oxidized to two molecules of ___; ___ and ___ are formed along the way

acetyl coA; acetyl; co2; nadh; fadh2

how many molecules of co2 are produced for one molecule of glucose in the citric acid cycle

4

how many molecules of NADH are produced for one molecule of glucose in the citric acid cycle

6

how many molecules of FADH2 are produced for one molecule of glucose in the citric acid cycle

2

how many molecules of ATP are produced for one molecule of glucose in the citric acid cycle

2

how many molecules of GTP are produced for one molecule of glucose in the citric acid cycle

2

NADH and FADH2 are ____ in the ____. the electrons pass through a series of membrane proteins called the ___ ___, found in the inner ___ ___

oxidized; mitochondria; respiratory chain; mitochondrial membrane

electron flow through the respiratory chain is ___; the energy is used to drive ___ transport of protons across the inner mitochondrial membrane

spontaneous; active

molecular ____ accepts the electrons from the last electron carrier protein to produce water; O2 is therefore called the ____ ____ ___

oxygen; terminal electron acceptor

without O2, the respiratory "fills up" with electrons and eventually stalls

true

as a final step, the energy stored in the proton gradient is used to make ATP from ____ and ___

ADP; Pi

an enzyme in the inner mitochondrial membrane, the mitochondrial ____ ____, couples the spontaneous movement of protons down their concentration gradient to the non-spontaneous synthesis of ATP; this process is called ____ ____

ATP synthase; oxidative phosphorylation

in the presence of ___, complete oxidation of one glucose molecule yields between ___ and ___ ATP molecules

O2; 32; 36

without O2, NADH is still made during ___ but it cannot be oxidized by the ____ ____ ___

glycolysis; electron transport chain

the NADH made in glycolysis is oxidized by ____ in the cytosol in the absence of O2

fermentation

all types of fermentation serve to regenerate ___; if this didn't happen, ____ would eventually come to a stop because this molecule is needed to make ___

NAD+; glycolysis; pyruvate

____ ____ fermentation in muscle limits the total amount of ATP that can be made to ___ ATP molecules per one glucose molecule, cutting it in half; the end product is ___ ___, which is later degraded

lactic acid; 2; lactic acid

___ fermentation occurs in the cytoplasm of certain yeast cells; only ____ ATP/glucose; end product is ___; ____ is released

ethanol; 2; ethanol; CO2