Topics 3-4 Flashcards
Catabolic Pathway and types
molecules are broken down and their energy is released. catabolic pathways yield energy by oxidizing organic fuels
Types
Fermentation
Cellular Respiration
What type of reaction is cellular respiration? what is it used for?
exergonic, release energy from glucose to phosphorylate ADP to ATP
What can be broken down for energy in cellular respiration, and what us mainly used?
Carbs, fats and proteins can be used but glucose is the primary nutrient for it
What is the cellular respiration reaction?
C6H12O6+6O2▶️6CO2+6H2O
Exergonic
NAD+
A coenzyme that serves as an electron carrier in cellular respiration, it stabilizes to form NADH when it receives 2 electrons
Glycolysis
Location: Cytosol
What happens: Glucose(6 carbon) is broken down into 2 pyruvate molecules(2, 3 carbon sugars) and 2 water molecules
Phases:
- Energy investment, 2 ATP used, 2ADP+2P yielded. Glucose is destabilized and made more reactive
- Energy payoff phase: 4ADP+4P form 4ATP. 2NAD+, 4 electrons, and 4H+ yield 2 NADH+2H20
Net: +2ATP(4 gained 2 used)
2 NADH+2H+ from energy payoff phase
What are the 2 NADH from glycolysis used for
They are utilized in the electron transport system
What happens between glycolysis and he citric acid cycle?
Pyruvate is oxidized to Acetyl CoA. transport protein moves pyruvate from the cytosol to the mitochondrial matrix, where an enzyme complex removes CO2, strips away electrons to convert NAD+ to NADH and adds coenzyme A to form acetyl CoA(2 per glucose).
Citric Acid cycle
Location: Mitochondrial Matrix
Purpose: The task of breaking down glucose is completed with CO2 released as waste
What happens: One input of Acetyl CoA=1 turn of the cycle, meaning 2 turns completely oxidizes glucose
Result from 1 turn: 2CO2, 3NADH, 1FADH2, 1 ATP
*each glucose yields twice these
What holds the energy in cellular respiration?
The electrons within the electron carriers
Oxidative Phosphoration
Purpose: Chemiosmosis couples electron transport to ATP synthesis, includes ETC
Location: Inner mitochondrial membrane
What happens: the ETC takes H+ from NADH and FADH2 and pumps it from the mitochondrial matrix to the intermembrane space to create a gradient, which powers chemiosmosis. The H+ go to the end of the ETC where a final electron acceptor, typically O2, bonds with them
Chemiosmosis
ATP synthesis powered by the flow of H+ across the gradient created by the ETC. It is an energy coupling mechanism
ATP Synthase
A transmembrane protein in the mitochondrial membrane containing a channel where H ions flow back down their gradient
Proton motive force
The gradient of hydrogen ions that phosphorylates ADP to ATP
How much ATP is yielded from Cellular Respiration? Oxidative phosphorylation?
Cellular Respiration: 30-32
Oxidative Phosphorylation: 26-28
Fermentation
An expansion of glycolysis where ATP is generated by substrate level phosphorylation, with NAD+ being the electron acceptor instead of Oxygen
Alcohol and lactic acid fermentation
Alcohol: pyruvate is converted to ethanol, releasing CO2 and oxidizing NADH in the process to create more NAD+
Lactic Acid: Pyruvate is reduced by NADH while forming NAD+ and lactate is the waste product
Facultative and obligate anaerobes
Facultative: Can make ATP by aerobic respiration if oxygen is present but can switch to fermentation under anaerobic conditions
Obligate: Can not survive in the presence of oxygen