Degrade complex molecules with high potential energy to simpler molecules with lower potential energy
Enzymes ________
Work; heat
The energy taken out when enzymes degrade molecules can be used to do _______; the rest is lost as ______
Aerobic respiration
Catablolic pathway in which oxygen is consumed as a reactant along with the organic fuel
Anaerobic respiration
Catabolic pathway that uses substances other than oxygen
Fermentation
Partial degradation of sugars or other organic fuel that occurs without the use of oxygen
C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy (atp)
Equation for respiration
redox reactions (oxidation-reduction reactions)
A chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another
Oxidation
the loss of electrons from a substance
Reduction
gain of electrons to a substance
reducing agent
The electron donor in a redox reaction.
oxidizing agent
The electron acceptor in a redox reaction.
When bonds form with more electronegative atom (usually oxygen)
When do redox reactions involve a partial loss of electrons
Oxygen
Strongest oxidizing agent
Shifted from less electronegative atom to a more electronegative atom
Electrons loose potential energy when _____
Oxidized ; reduced
Glucose is ______ in respiration ; oxygen is _____
Organic molecules with many carbon-hydrogen bonds
Great sources of energy for cells
A hydrogen atom (electron and proton)
In redox reactions, electrons are usually transferred in the form of _____
Coenzyme NAD+
Electron carrier that accepts hydrogen atoms
Oxidized : NAD+ Reduced: NADH
Oxidized form of Nad+ is _______, reduced form is _______
oxidizing agent
NAD+ is an ______ during respiration
dehydrogenase enzymes
Enzymes that transfer hydrogens to NAD+ in a redox reaction
used later in respiration to make ATP
energy in NADH can be _______
2 hydrogens (and their electrons) are transferred to the final electron acceptor, oxygen
in respiration, water is formed when _____
electron transport chain
in respiration, energy is released in several small steps using a _______
Electron transport chain
a sequence of electron carrier molecules (membrane proteins) that shuttle electron down a series of redox reactions that release energy used to make ATP
slightly more electronegative and the previous carrier molecule
each carrier in an electron transport chain is _____
Oxygen
what is the final (terminal) electron acceptor in electron transport chain
glycolysis, pyruvate oxidation, and oxidative phosphorylation
3 stages of respiration
cytosol
glycolysis occurs in the ______
glucose (6 carbons) to 2 molecules of pyruvate (each with 3 carbons)
glycolysis involves breaking down _______
acetyl CoA; citric acid cycle
pyruvate is oxidized to _______; this then enters _______
NADH and FADH2
in citric acid cycle, electrons are transferred to _____ and _________
substrate-level phosphorylation
involves the direct transfer of a phosphate group from a substrate molecule to ADP
10% ; substrate level phosphorylation
only ___% of ATP made during respiration is made by _____
energy investment stage and energy payoff stage
2 steps of glycolysis
2 ATP, 2 NADH, and 2 pyruvate
glycolysis produces a net of ____
pyruvate; mitochondrion
_____ enters the _____ during aerobic respiration in eukaryotes
CO2; NAD+ is reduced to NADH + H+
When pyruvate is being converted to acetyl- CoA, ____ is released and _______
citric acid cycle
pyruvate is overall broken down to 3CO2 in _______
NADH and FADH2
in citric acid cycle, chemical energy is transferred to ____ and ____
the 2 carbon molecule acetyl CoA combines with the 4 carbon molecule oxaloacetate and produces citrate (6 carbon molecule)
In the first reaction of the citric acid cycle, ______ combines with ______ and produces _____
electron carrier
FAD is an____
oxaloacetate; acetyl-CoA
at the end of citric acid cycle, ____ is regenerate and can be reused to combine with another _____ and restart the cycle again
of 4 ATP for each glucose molecule; substrate-level phosphorylation
Glycolysis and citric acid cycle produce total ____ and only by _____
NADH and FADH2
By the end of citric acid cycle, most of energy from glucose is now in form of ____
flavoprotein
in electron transport chain, NADH first transfers electrons to _____
iron--sulfer proteins, ubiquinones and cytochromes
After flavoprotein, the rest of chain consists of _____, ___ and ____
water
At end of electron chain, oxygen is converted to ____
ATP synthase
enzyme complex that makes ATP from ADP and inorganic phosphate
H+ gradient
ATP synthase used a _____ to power the synthesis of ATP from ADP
Chemiosmosis
the process in which energy stored in the form of a hydrogen ion gradient across a membrane is used to preform cellular work
mitochondrial inner membrane into the intermembrane space
electron transport chain also pumps H+ ions cross the _____ into the _____ and creates the H+ ion gradient
proton-motive force
H+ gradient that powers ATP synthase is chemiosmosis is called ______
Glycolysis: 2
citric acid cycle: 2
oxidative phosphorylation: 26-28
how many molecules of ATP do we get in glycolysis, citric acid cycle, and oxidative phosphorylation?
30-32 ATP
total amount of ATP for each glucose in cellular respiration?
anaerobic respiration and fermentation
2 other ways cell can oxidize glucose to make ATP without using oxygen?
electron transport chain but down not use oxygen as terminal electron acceptor
anaerobic respiration has ___ but does not ____
electron transport chain at all
fermentation does not use ____
substrate-level phosphorylation
fermentation makes ATP by ____
reducing pyruvate
fermentation regenerates NAD+ by _____
alcoholic fermentation
glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide
ethyl alcohol in order to regenerate NAD+; CO2
in alcoholic fermentation, pyruvate is reduced to _______ in order to _____, ____ is released during this process
obligate anaerobes
organisms that carry out only fermentation or anaerobic respiration
facultative anaerobes; muscle cells
an organism that makes ATP by aerobic respiration of oxygen is present but switches to anaerobic respiration of fermentation if oxygen is not present; example _______
fats, proteins, and carbohydrates
____ ,____ , and _____ can be used for fuels by glycolysis
feedback inhibition
when the end produce of an anabolic pathway inhibits the enzyme that catalyzes an early step of the pathway