Cell Respiration Flashcards
Define Cellular Respiration
Release of energy from food molecules to synthesize ATP
What is the overall chemical reaction of Cell Respiration?
Organic Compound + O2 –> CO2 + H2O + ATP + heat
Define Glycolysis
Breaking carbohydrates. 1 Glu –> 2 Pyruvate. 10 Step process.
Define Citric Acid Cycle (aka Kreb’s Cycle aka TCA)
A cyclic metabolic pathway that occurs in the matrix of the mitochondria and requires an aerobic environment (even though it doesn’t directly use O2)
Define Oxidative Phosphorylation
A process that occurs in the cristae (inner membrane) of the mitrochondria and includes the ETC and Chemiosmosis. It takes in all the electrons from the previous steps and produces the bulk of the cell’s ATP.
Define Electron Transport Chain
A group of protein complexes embedded in the cristae of the inner mitochondrial membrane. Accepts/donates electrons in a linear manner in a series of reactions. NADH/FADH2 molecules produced from Glycolysis and the CAC donate electrons to the ETC. Electrons are transferred from one protein to the next. With each transfer, energy is released. Ultimately, the electrons are passed to O2, forming water. NAD+ and FAD recycle back to pick up more electrons from glycolysis, prep reaction, and CAC.
Name the location, reactants, intermediates (NADH, FADH2), and products of each stage of Glycolysis
Location: Cytoplasm
Reactants: 2x ATP
Intermediates: ???
Products: 4x ATP, 2x Pyruvate, 2x NADH
Name the location, reactants, intermediates (NADH, FADH2), and products of each stage of the Preparatory Reaction (aka Pyruvate Oxidation)
Location: Matrix
Reactants: 2x Pyruvate
Intermediates: ???
Products: 2x Acetyl-CoA, 2x CO2, 2x NADH + H+
Name the location, reactants, intermediates (NADH, FADH2), and products of each stage of CAC (aka Kreb’s Cycle aka TCA)
Location: Matrix
Reactants: 2x Acetyl-CoA
Intermediates: ???
Products: Oxyloacetate, 2x ATP, 2x FADH2, 4x CO2, 6x NADH
Name the location, reactants, intermediates (NADH, FADH2), and products of each stage of Oxidative Phosphorylation (aka ETC + Chemiosmosis)
Location: Cristae (inner membrane of mitochondria)
Reactants: 8x NADH, 2x FADH2
Intermediates: ???
Products: NAD+ + FAD + 30-34x ATP, H20
Describe the role of oxygen in oxidative phosphorylation
Oxygen is the final electron acceptor (it gets reduced), combines with H+’s in the matrix, forms water.
Compare and Contrast the relative amounts of ATP production with each phase of cellular respiration
Glycolysis: 4x ATP
Prep Step: 0x ATP
KC/CAC/TCA: 2x ATP
Oxid Phosph: 30-34x ATP
Is cellular respiration a catabolic or anabolic reaction?
Catabolic
For each Glucose molecule of cellular respiration, how many (net) ATP molecules are produced?
36-38x ATP
Compare and contrast Cellular Respiration (3) and Fermentation (2) in general
Cellular Respiration:
Complete breakdown of organic molecules in the presence of O2. More efficient. More widespread.
Fermentation:
Partial degradation of organic molecules. O2 is absent.
Both:
Make ATP
Describe the overall general picture of Cellular Respiration (include cytoplasm, mitochondrion NADH/FADH2, ATP, Glucose, Pyruvate, Acetyl CoA, ETC, chemiosmosis, substrate-level phosph, and oxidative phosph in your description)
[see diagram]
Does glycolysis require O2? Where does glycolysis occur?
No.
Cytoplasm.
What are the 3 general phases of Glycolysis?
- Energy Investment
- Cleavage
- Energy Liberation
What is the chemical reaction for reducing NAD+ to NADH?
NAD+ + 2H+ + 2e- –> NADH + H+
List the overview of Glycolysis (occurs in…atp input…atp produced…net atp gain…NADH produced…final product)
Occurs in cytoplasm. ATP input: 2x ATP ATP Produced: 4x ATP Net ATP gain: 2x ATP NADH produced: 2x NADH Final Product: 2x Pyruvate
What determines the fate of the 2x Pyruvate that came from the Glucose molecule?
O2.
In aerobic conditions, Pyruvate is prepped for CAC.
In anaerobic conditions, Pyruvate undergoes Fermentation.
Where does the Preparatory Reaction occur? What is happening in general during this step?
Occurs in the matrix.
Pyruvate is converted into Acetyl-CoA by removing CO2 and attaching CoA.
Also, NAD+ is reduced to NADH and H+
List the Preparatory Reaction Overview (occurs in…ATP input…ATP produced…Net ATP gain…NADH produced…Other molecules produced…Final Product)
Occurs in the matrix of the mitochondria.
ATP input: 0x ATP
ATP produced: 0x ATP
Net ATP gain: 0x ATP
NADH produced: 2x NADH
Other molecules produced: 2x CO2, 2x Acetyl-CoA
Final Product: 2x Acetyl-CoA
Does the Kreb’s Cycle require O2?
Yes, but it doesn’t directly use it!
What is the first reaction of the Kreb’s Cycle? How many steps are there in this cycle?
Oxaloacetate + Acetyl-CoA –> Citrate
8 steps
List the Kreb’s Cycle Overview (occurs in the…ATP input…ATP produced…Net ATP gain…NADH produced…FADH2 produced…Other molecules produced…Final Product)
Occurs in the matrix. ATP input: 0x ATP ATP produced: 2x ATP Net ATP gain: 2x ATP NADH produced: 6x NADH FADH2 produced: 2x FADH2 Other molecules produced: oxaloacetate, 4x CO2 Final Product: oxaloacetate
Describe the Electron Transport Chain (6)
- Proteins embedded in cristae of mitochondria
- Accept/donate electrons in a linear manner in a series of rxns
- NADH/FADH2 molecules made during glycolysis and the CAC donate electrons to the ETC
- Electrons are transferred from one protein to the next
- With each transfer, energy is released
- Ultimately, the electrons are passed to O2 (reduction), forming water
What is Electron Transport Phosphorylation?
Electron transfer in the ETC causes proteins to pump H+’s from the matrix ([low H+]) to the intermembrane space which has a [HIGH H+]
What is Phosphorylation? (Think: chemiosmosis)
H+’s reenter the matrix by passing through (facilitated Diffusion) channel protein called ATP synthase. ATP synthase uses this H+ [conc] gradient to drive phosphorylation of ATP.
Define chemiosmosis
The use of energy from a concentration gradient to drive cellular work
List the Oxidative Phosphorylation Overview (occurs in the…ATP produced…Other molecules produced)
Occurs in the cristae.
ATP produced: 30-34x ATP
Other molecules produced: H2O, NAD+, FAD
The final electron acceptor of the ETC is ____________, which goes on to combine w/ ______________ in the matrix to form _____________.
Oxygen, H+ ions, H2O
