Chapter 7 Respiration Flashcards
Cellular respiration can occur through two primary pathways
aerobic and anaerobic
__ is a fundamental metabolic process in all green
plants, where it utilizes oxygen to metabolize photosynthetic products like glucose and
starch.
Aerobic respiration
key stages in respiration
Glycolysis
TCA/Krebs cycle
ETC
Where it occurs:
Glycolysis=
TCA/Krebs cycle=
ETC=
Glycolysis= cytoplasm
TCA/Krebs cycle= mitochondrial matrix
ETC= inner mitochondrial membrane
glucose is broken down
into pyruvate, yielding a small amount of ATP and reducing equivalents in the form of
NADH.
Glycolysis
2 phase of glycolysis
Investment phase (first five stages);
Pay-off phase
the Investment phase of glycolysis is an ___
reaction, in which they give energy
endothermic
Pay-off phase:
4 ___,
2 ____, and
2 ___molecules.
ATP;
NADH + H+;
pyruvate
which of the 10 step of glycolysis are the regulatory steps?
steps 1,2 and 7
where pyruvate is further
oxidized. This cycle produces additional NADH and FADH₂, as well as ATP and CO₂.
This process includes eight (8) steps.
Tricarboxylic Acid (TCA) Cycle:
final step, the electrons carried by NADH and FADH₂ are transferred through a series of protein complexes
Mitochondrial Electron Transport Chain
The foundational compounds utilized in this process originate from the
metabolic pathways involved in __and ___. The byproducts
of these pathways serve as vital building blocks, known as __ or __
glycolysis and the Citric Acid Cycle;
carbon skeletons or
biosynthetic precursors
Anaerobic pathway begins with ___, where glucose is partially broken
down to produce a small amount of ATP
glycolysis
The last and final stage of the respiration in plants occurs in the inner
mitochondrial membrane specifically in the electron transport chain in a process called ___
oxidative phosphorylation.
is the primary energy producer in cellular
respiration. It generates the majority of ATP
Oxidative phosphorylation
series of protein complexes and small
molecules located in the inner membrane of mitochondria; main function is to transfer electrons from electron
carriers, such as NADH and FADH₂, to oxygen, the final electron acceptor, while
simultaneously pumping protons (H⁺) across the membrane to generate a proton
gradient.
electron transport chain (ETC)
Protein components involved in the Electron Transport Chain (7)
NADH-Coenzyme Q Oxidoreductase (Complex I) ;
Succinic-Coenzyme Q Dehydrogenase (Complex II);
Ubiquinone (Coenzyme Q);
Coenzyme Q-cytochrome C complex (Complex III) ;
Cytochrome C;
Cytochrome c Oxidase (Complex IV);
ATP Synthase
This protein complex is the first entry point for protons through the electron
transport chain. It catalyzes the oxidation of NADH by coenzyme Q10
(Ubiquinone).
NADH-Coenzyme Q Oxidoreductase (Complex I)
This protein complex is the second entry point for protons into the electron
transport chain. Catalyzes the oxidation of FADH2 by coenzyme Q10.
Succinic-Coenzyme Q Dehydrogenase (Complex II)
Carrier protein that functions as an electron carrier and transfers electrons from
complex I/II to complex III.
Ubiquinone (Coenzyme Q)
This complex catalyzes the oxidation of QH2 and the reduction of cytochrome
c and ferritin. Cytochrome c carries an electron in this reaction.
Coenzyme Q-cytochrome C complex (Complex III)
Protein that carries electrons from one complex of integral membrane proteins
of the inner mitochondrial membrane to another
Cytochrome C
The final protein complex in the electron transport chain, this protein mediates
the transfer of electrons to the final electron acceptor, oxygen.
Cytochrome c Oxidase (Complex IV)
This enzyme uses the proton-motive force generated by the proton
concentration gradient to phosphorylate ADP and form ATP.
ATP Synthase
process of oxidative phosphorylation begins with
NADH and FADH2
is a highly electronegative molecule, meaning it has a strong affinity for
electrons.
Oxygen
Other Function of Oxidative Phosphorylation in Plants (2)
Photorespiration;
Redox Balance
is a wasteful process in plants that occurs when oxygen is mistakenly
incorporated into the Calvin cycle instead of carbon dioxide. This “mistake” happens
under conditions such as high temperatures and low CO2 levels, when oxygen competes
for the enzyme RuBisCO, which normally catalyzes the first step of carbon fixation
Photorespiration
In photorespiration, Instead of producing glucose, this error leads to the formation of ___, a less
efficient byproduct that can harm the plant and reduces photosynthetic efficiency
glycolate
in OXPHOS, proton pumps create an electrochemical ____ gradient and this gradient powers ATP synthesis via ATP synthase.
proton gradient
when managing excess reducing equivalents during photosynthesis,
plant mitochondria can bypass ATP generation by utilizing ___ or mitochondrial ___
alternative oxidases
(AOXs);
uncoupling proteins (UCPs)
transfer electrons directly
to oxygen, forming water without proton pumping
. AOXs alternative oxidases
allow protons to return
to the mitochondrial matrix without driving ATP synthesis
UCPs uncoupling proteins
movement of hydrogen ions across the membrane via ATP synthase. It involves
the coupling of endergonic reactions and exergonic reactions within the mitochondria.
Chemiosmosis
Key Mechanisms in Oxidative Phosphorylation (2)
Chemiosmosis
Electron Transport Chain as Controlled Energy Release
serves as the coupling mechanism between the electron transport
chain and ATP synthesis.
Chemiosmosis
Importance of Oxidative Phosphorylation (3)
Energy Production
Alternative for Photosynthesis
Stress Responses
INTERNAL FACTORS controlling respiration (5)
Type of substrate
Photosynthesis
Age and type of tissue
Biological stress
Genotype or species
Respiratory substrate may be (3)
carbohydrate, protein or fats
The kind
of substrate being oxidized can be determined by measuring the ___
Respiratory Quotient
EXTERNAL FACTORS controlling respiration (4)
Oxygen
Temperature
CO2 levels
Light
phenomenon, where anaerobic respiration is inhibited by the presence of oxygen, is
known as the ___
Pasteur effect.
plant species has an optimal temperature range for respiration,
generally between __
18°C and 40°C
The relationship between temperature and respiration is often described by
the ___, indicating that respiration rates typically change proportionally with
every 10°C shift
Q10 effect
Enzyme activity is most effective between ___
30°C and
35°C
is an anaerobic pathway that occurs in the cytoplasm, breaking down
glucose into pyruvate and producing a small amount of ATP (2 net ATP) and NADH
Glycolysis
is an aerobic pathway that occurs in the mitochondrial matrix, further
breaking down pyruvate into CO2 and producing a significant amount of ATP (2 ATP),
NADH, and FADH2, which are then used in the electron transport chain to generate
more ATP
Krebs cycle
ATP synthesis without involvement of electron transport
SUBSTRATE-LEVEL PHOSPHORYLATION
products of glycolysis and which step they were produced
4 ATP (Net yield: 2 ATP) (Steps 7 and 10)
2 NADH + 2 H+ (Step 6)
2 H2O (Step 9)
2 pyruvate (Step 10)
Krebs cycle:
For every Acetyl CoA that enters it produces:
3 NADH (steps 3, 4, and 8)
1 FADH2 (step 6)
1 ATP (step 5)
