Cellular respiration Flashcards
_________within a cell involves many chemical reactions where electrons are
transferred from one chemical to another during.
Energy production
_______-loss of electrons in a chemical reaction
Oxidation
_______-gain of electrons in a chemical reaction
Reduction
In reduction reactions:
Because these reactions usually occur together, these pairs of reactions are called
__________
redox reactions.
In reduction reactions:
Example: Catabolism of glucose involves transfer of electrons to oxygen
producing water and carbon dioxide.
§ As the reducing agent (C6H12O6) 3)_____________________ electrons,
the 4)_______________ agent (O2) accepts electrons.
3) loses
4) Oxidizing
In reduction reactions:
_________ - enzymes that catalyze redox reactions.
§ Most of these enzymes require small molecules (coenzymes) that are able
to accept and carry the electrons (electron carriers
Dehydrogenases and oxidases
What does Nicotinamide adenine dinucleotide (NAD+) get reduce to form?
NADH
What does Flavin adenine dinucleotide (FAD) get reduced to form?
FADH_2
_______-a series of metabolic pathways that extracts energy from the bonds in
glucose and uses this energy to synthesize 5)____________
Cellular respiration
5) ATP
What are the to main types of cellular respiration?
Aerobic respiration
and Anaerobic respiration
What type of cellular respiration is this?
______-requires oxygen and involves the
mitochondria producing a large amount of ATP.
Aerobic respiration
Within Aerobic respiration there is a sequence of four pathways that yeilds about 30 ATP per glucose what they? (in order!!)
- Glycolysis
- Pyruvate Dehydrogenase Complex
- Citric Acid Cycle
- Oxidative Phosphorylation
What type of cellular respiration is this?
______-does not require oxygen or
mitochondria but produces much less ATP
Anaerobic respiration
With the Anaerobic respiration there is a sequence of two pathways that yields 2 ATP per glucose what are they? (in order!!!)
- Glycolysis
2. Lactic Acid Fermentation
______-catabolic pathway that converts glucose into two pyruvate molecules occurs
in the cytoplasm.
Glycolysis
In glycolysis is oxygen (anaerobic) require?
No is not require
In glycolysis a six-carbon molecule is broken down into ______ three-carbon molecules
two
Glycolysis store energy as :
Two molecules of 9)______ and two molecules of 10)____________
9) ATP
10) NADH(electron carries)
What is the first step of Glycolysis?
Hexokinase catalyzes a phosphorylation reaction where a phosphate group is
transferred from ATP to glucose producing Glucose-6-phosphate.
What is the second step of Glycolysis?
Phosphoglucose isomerase catalyzses an isomerization reaction that reorganizes the
atoms of glucose-6-phosphate producing Fructose-6-phosphate.
What is the third step of Glycolysis?
Phosphofructokinase uses an ATP to activate fructose-6-phosphate by
phosphorylation producing fructose-1,6-bisphosphate.
What is the fourth step of Glycolysis?
Fructose bisphosphate aldolase produces two 3 carbon molecules dihydroxyacetone
diphosphate (DHAP) & glyceraldehyde-3-phosphate (G3P).
What is the 5 step of Glycolysis?
Triose phosphate isomerase converts DHAP into another G3P.
o Steps 6-10 occur twice per glucose because two molecules of G3P are produced
from each glucose.
What is the 6 step of Glycoslysis
In step six the enzyme Glyceraldehyde-3 phosphate (G3P) dehydrogenase catalyzes
the oxidation of G3P and reduction of NAD to produce 1,3-Bisphosphoglycerate (1,3-
BPG) and a high energy NADH molecule.
What is the 7 step of Glycolysis?
Phosphoglycerate kinase transfers a phosphate from 1,3-BPG to ADP producing one
ATP and 3-phosphoglycerate (3-PG).
What is the 8 step of Glycolysis?
Phosphoglycerate mutase catalyzes the isomerization reaction that converts 3-PG into
2-phosphoglycerate (2-PG).
What is the 9 step of Glycolysis
Enolase converts 2-PG into phosphoenolpyruvate (PEP) releasing a molecule of
water.
What is the 10 step of Glysolysis?
Pyruvate kinase transfers a phosphate group from PEP to ADP producing a molecule
of ATP and pyruvic acid.
What is the summary of Glycolysis?
Glucose + 2 ADP + 2 Pi + 2 NAD+→ 2 Pyruvate + 2 ATP + 2 NADH
The Fate of pyruvate:
In anaerobic conditions pyruvate enters 12)__________ Fermentation: the
enzyme lactate dehydrogenase oxidizes NADH and reduces pyruvate forming lactate.
o Produces 2 ATP per glucose (less efficient that aerobic respiration)
12)Lactic Acid Fermentation
The Fate of pyruvate:
In aerobic conditions pyruvate enters the mitochondria where the 13)________________
performs oxidation of pyruvate releasing one carbon as CO2 and transferring the other
two carbons onto the sulfur atom of Coenzyme-A (CoA) forming the molecule
14)___________ that will enter the citric acid cycle next.
o 1NAD+ is reduced to NADH for each pyruvate oxidized.
13) CO_2
14) Acetyl CoA
______-Metabolic pathway that occurs in the matrix of the
mitochondria and converts the two carbons of acetyl-coA into two Co_2 molecules.
Citric Acid Cycle (Krebs Cycle)
How does the Citric Acid Cycle Harvest the energy as?
3 NADH per Acetyl-CoA or 6 NADH per glucose
o 1 FADH2 per Acetyl-CoA or 2 FADH2 per glucose
What is the first Step of the Citric Acid Cycle
Citrate synthase combines acetyl CoA and oxaloacetate to form a six-carbon citrate
molecule.
What is the second step of the citirc Acid Cycle?
Aconitase converts citrate into isocitrate
What is the 3 step of the citirc Acid Cycle?
Isocitrate dehydrogenase converts isocitrate into the five-carbon α-ketoglutarate
releasing a molecule of CO2 and forming a high energy NADH.
What is the 4 step of the Citric Acid Cycle?
α-ketoglutarate dehydrogenase- converts α-ketoglutarate into the four-carbon
succinyl CoA releasing a molecule of CO2 and forming a high energy NADH.
What is the 5 step of the Citric Acid Cycle?
Succinyl CoA dehydrogenase- converts succinyl CoA into succinate and forms the
high-energy molecule GTP, which transfers its energy to ADP to produce ATP.
What is the 6 step of the Citric Acid Cycle?
Succinate dehydrogenase- converts succinate into fumarate, forming a high energy
molecule of FADH2.
What is the 7 step of the Citric Acid Cycle?
Fumarase- converts fumarate into malate.
What is the 8 step of the Citric Acid Cycle?
Malate dehydrogenase- converts malate into oxaloacetate while reducing NAD+ to
NADH. Oxaloacetate is then ready to start the cycle again with another acetyl CoA.
What is the summary of the Citric Acid Cycle?
Acetyl-CoA + 3 NAD+ + FAD → 2 CO2 + 3 NADH + FADH2
In Summary of citric Acid Cycle:
______-provide the energy that fuels oxidative phosphorylation
NADH and FADH2
In Summary of citric Acid Cycle
Two GTP (similar to ATP) are also produced during the citric acid cycle but they are
canceled out by two ATP used to transport the ________ produced during glycolysis into
the mitochondria to be used for oxidative phosphorylation.
NADH
The reactant of Glycolysis and PDC is:
Glucose + 2 ADP + 2 Pi + 4 NAD+→
the product?
Product is:
2 CO2 + 2 Acetyl CoA + 2 ATP + 4 NADH
The reactant of the Summary of Citric Acid Cycle is:
2 Acetyl CoA + 6 NAD+ + 2 FAD → What is the Product?
4 CO2 + 6 NADH + 2 FADH2
The Overall Summary for Glycolysis, PDC, and Citric Acid Cycle is :
Glucose + 2 ADP + 2 Pi + 10 NAD+ + 2 FAD→
What is the product
6 CO_2 +2 ATP+10 NADH+2 FADH_2
_______-a metabolic pathway that uses oxygen to release the energy stored
in NADH and FADH2 producing H2O and a large amount of ATP.
• Requires oxygen and occurs at the inner mitochondrial membrane
Oxidative Phosphorylation
What are the two major parts of the phosphorylation ?
Electron transport Chain (ECT)
and Chemiosomes
In the first part of the Electron transport chain (ETC):
Electrons from NADH and FADH2 are passed down a chain of protein complexes
embedded in the inner membrane of the ________
mitochondria.
In the first part of the Electron transport chain (ETC):
Electrons fall to lower energy levels as they are passed down the chain (releases
energy) and this energy is used to drive the active transport of H+ (protons) out of
the __________ across the inner membrane.
mitochondrial matrix
In the first part of the Electron transport chain (ETC):
Oxygen is the final electron acceptor that binds to 2 _____ to form water
H+
What is the first Complex of the ETC?
Complex I (NADH:ubiquinone oxidoreductase)- oxidizes NADH and reduces ubiquinone forming NAD+ and ubiquinol. • 4 H+ are pumped out of the mitochondrial matrix.
What is the second Complex of the ETC?
Complex II (succinate dehydrogenase)- oxidizes FADH2 and reduces ubiquinone forming NAD+ and ubiquinol
What is the third Complex of the ETC?
Complex III (ubiquinol:cytochrome c oxidoreductase)- oxidizes ubiquinol to form ubiquinone and reduces cytochrome-C. • Pumps 4 H+ out of the mitochondrial matrix.
What is the fourth Complex of the ETC?
Complex IV (cytochrome c oxidase)- oxidizes cytochrome-C as oxygen
(O2) is reduced and combines with 4 H+ forming 2 H2O.
• 4 H+ are also pumped out of the mitochondrial matrix.
Summary of the ETC:
- 10 H+ pumped out of the mitochondria for each ______
- 6 H+ pumped out of the mitochondria for each _______
- NADH oxidized
* FADH2 oxidized.
What is the first part of the oxidative phosphorylation called?
Electron transport
What is the second part of the oxidative phosphorylation called
Chemiosmosis “chemical diffusion”
In the second part Chemiosmosis:
The energy released by electrons moving down the chain is used to pump H+
from the _______ to the intermembrane space.
matrix
In the second part Chemiosmosis:
This creates a _____gradient (potential energy).
proton “(H+) hydrogen ion”
In the second part Chemiosmosis:
This gradient is a force (the proton (H+) (motive force) that drives protons back into
the ________
mitochondrial matrix.
In the second part Chemiosmosis:
As protons enter the mitochondria this kinetic energy is converted to chemical
potential energy by the enzyme _________ that catalyzes the
phosphorylation of ADP to produce ATP: ADP + Pi → ATP
ATP synthase
Overall Maximum of _____ATP Produced by Cellular Respiration of
Glucose
It is unlikely that most cells actually achieve this theoretical maximum. Efficiency
varies from cell to cell and depends on a number of factors.
30-36
In a Overall Maximum of 30-36 ATP Produced by Cellular Respiration of Glucose
*The proton motive force also provides the energy for an active transport
mechanism that moves ADP + Pi into the ___________ and ATP out of the
mitochondria.
mitochondria
In a Overall Maximum of 30-36 ATP Produced by Cellular Respiration of Glucose
*H+ can also leak across the inner mitochondrial membrane further decreasing
the efficiency of _______
oxidative phosphorylation.
_______-synthesis of glucose from non-carbohydrates.
• Can start with glycerol, lactic acid or various amino acids.
Gluconeogenesis
_______-breakdown of proteins releasing amino acids.
Protein Catabolism
______-in the liver nitrogen containing amine group is removed from
amino acids producing the waste product ammonia (NH3).
Demination
Carbon skeletons produced by deamination of amino acids can be used for
gluconeogenesis or enter the _______
citric acid cycle.
_______-the hydrolysis of triglycerides into glycerol and fatty acids
Lipolysis
Part of the Lipolysis
______-is converted into glyceraldehyde phosphate a glycolysis
intermediate that can enter into the citric acid cycle or be used for
gluconeogenesis.
The glycerol
Part of the Lipolysis
_______-acids enter b-oxidation- enzymes in the mitochondria catabolize
fatty acids producing Acetyl CoA that enters the citric acid cycle.
Fatty Acids enter B-oxidation
________-production of ketone bodies from acetyl CoA that occurs when
acetyl CoA production exceeds the capacity of the citric acid cycle to process it.
Ketogenesis
______-ketones are converted to acetyl-CoA and enter the citric acid cycle.
Ketone oxidation
