Differ between aerobic and anaerobic respiration pathways
Aerobic Respiration- The breakdown of organic molecules using oxygen
Anaerobic Respiration- The breakdown of organic molecules WITHOUT using oxygen
Describe redox reactions. What is oxidation? What is reduction?
A redox reaction involves the transfer of electrons from one molecule to another resulting is an oxidized molecule and a reduced molecule
Oxidation is when a molecule LOSES an electron and donates the e- to another molecule
Reduction is when a molecule GAINS an electron and accepts the e- from another molecule
LEO goes GER (Lose Electron ->oxidation, Gain Electron -> Reduction)
What is the role of redox reaction in cellular respiration?
In reducing NAD+ and FAD into NADH and FADH2, and creating the proton motive force by oxidizing NADH and FADH2 on the ETC
Name the major processes involved in cellular respiration
(location in a eukaryotic cell, primary inputs (reactants), primary outputs (products), whether the ATP produced is substrate-level phosphorylation or oxidative phosphorylation)
Glycolysis
Location: Cytoplasm (outside the mitochondria)
Primary Inputs (reactants): Glucose, 4 ATP, 2 NAD+
Primary Outputs (products): 2 Pyruvates, 2 ATP, 2 NADH
ATP: Substrate-level phosphorylation
Pyruvate Modification
Location: Matrix (inside the mitochondria)
Primary Inputs (reactants): 2 Pyruvates
Primary Outputs (products): 2 CO2, 2 Acetyl Co-A, 2 NADH
ATP: none produced
Citric Acid Cycle/Krebs Cycle
Location: Matrix
Primary Inputs (reactants): 2 Acetyl Co-A
Primary Outputs (products): 4 CO2, 2 ATP, 2 FADH2, 6 NADH
ATP: substrate-level phosphorylation
Oxidative Phosphorylation
Location: ACROSS the Inner Membrane of the Mitochondria
Primary Inputs (reactants): NADH, FADH2, Oxygen (O2)
Primary Outputs (products): H2O, ATP, NAD+, FAD+
ATP: Oxydative Phosphorylation
Describe the difference between substrate-level phosphorylation and oxidative phosphorylation
Substrate-level phosphorylation uses ENZYMES to combine ADP and Pi to make ATP
Oxidative Phosphorylation uses a series of REDOX REACTIONS (Electron Transport Chain) to combine ADP and Pi to make ATP
Differentiate between the energy investment and the energy payoff phases of glycolysis
The energy investment phase happens first and requires an input of ATP in order for the reactions of this phase to continue
The energy payoff phase happens after the investment phase and releases ATP after the reactions of this phase occur
Describe the modification of pyruvate that occurs before the citric acid cycle. Why is this necessary?
The carboxyl group (COOH) of pyruvate is removed and releases CO2 as a result. The enzyme acetyl Co-A binds where the carboxyl group previously was. This step is necessary so that the citric acid cycle can occur since pyruvate cannot enter as it is
Describe the initial reactions of the citric acid cycle
The Co-A of acetyl Co-A is removed leaving acetyl (2 C)
The acetyl (2 C) combines with oxaloacetate (4 C) to create citrate (6 C)
Then a series of enzyme-catalyzed reactions occur
The citric acid cycle begins and ends with the same molecule- oxaloacetate. How is this possible?
As the citric acid cycle occurs, the carbons and electrons of citrate get removed eventually ending with 4 Carbons left which make up oxaloacetate, and the carbons of oxaloacetate get used again to create citrate. Creating a cycle
Summarize the processes involved in oxidative phosphorylation need to know in more detail than other steps
Electron Transport Chain
NADH and FADH2 oxidize by attaching to the starting transport proteins of the electron transport chain, releasing electrons and H+
The electrons travel down the ETC and "lose" some potential energy (P.E) as they move towards the highly electronegative oxygen at the end of the chain
Once the electrons reach the end of the ETC, H+ and e- combine with O2 to create water
As the electron moved through the ETC, the P.E "lost" was used to pull the H+ against their gradient and into the high [H+] in the IMS
RESULTS IN THE PROTON MOTIVE FORCE ( [H+] gradient)
Chemiosmosis
The high [H+] in the Intermembrane Space (IMS) travels with the gradient through the enzyme ATP synthase
The movement of H+ rotates the ATP synthase, providing energy to catalyze ADP and Pi into ATP
Produces significantly more ATP than the other steps of cellular respiration
What role for oxygen play in oxidative phosphorylation?
Oxygen is highly electronegative so it plays the role of attracting electron to itself through the ETC; which results in the creation of the proton motive force
How is the proton motive force generated in oxidative phosphorylation?
As electrons move through the ETC, the P.E that is generated helps the H+ in the matrix move against their gradient into the IMS which creates a high to low concentration gradient from the IMS to the Matrix
What purpose does the proton motive force play in oxidative phosphorylation?
For H+ to travel from a [high] to [low] through the ATP synthase so that the enzyme can rotate and produce a lot of ATP
Differ between the two main types of fermentation pathways
Alcoholic Fermentation
Creates ethanol -Carried out by bacteria/fungi
Lactic Acid Fermentation
Creates lactate -Carried out by bacteria/human muscle cells (when low on O2)
How do carbohydrates, proteins, and fats compare in terms of their ease of use in metabolic pathways and their energy content?
Order of ease (easiest to hardest)
Carbohydrates
Proteins
Fats *2 and 3 require prior processing
Order of energy content (highest to lowest)
Fats
Proteins & Carbohydrates
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