F. Cellular Respiration
➢$ C_6H_12O_6 + 6O_2 ⟶6CO_2 + 6H_2O + ATP$
➢ Aerobic respiration: ATP made in the presence of oxygen
➢ Anaerobic respiration: ATP made without presence of oxygen
➢ 1. GLYCOLYSIS
- Glucose is split
- Glucose 6-carbon; when it is split it makes 2 3-carbon pyruvates
- Creates 2 ATP (net)
- NADH created from the transfer of electrons to NAD+
- Occurs in cytoplasm
- Glucose + 2 ATP + 2 NADh ⟶2 Pyruvate + 4 ATP + 2ND
➢ 2. FORMATION OF ACETYL CoA
- $ 2Pyruvate + 2 Coenzyme A + 2 NAD^+ ⟶2 Acetyl-CoA + 2CO^2 + 2 NADH$
- Extra carbons leave cell as $CO_2$
➢ 3. CITRIC ACID CYCLE
- Aka Krebs cycle
- Each acetyl coa will enter Krebs cycle on at a time, and all carbons will be turned into $CO_2$ eventually
- Acetyl $CoA$ combines with oxaloacetate (4-carbon) to create citric acid
- Active transport into mitochondria via cotransport with oxygen
- citric eventually gets turned back into oxaloacetate
- 3 types of energy produced:
■ $1ATP$
■ $3 NADH$
■ $1 FADH_2$
○ Atthis point there are 4 ATP, 10 NADH, and 2 FADH2 total
➢ 4. OXIDATIVE PHOSPHORYLATION
- As electrons are removed from a molecule of glucose, they carry with them as much of the energy that was originally stored within their bonds
- These electrons are then transferred to readied carrier molecules–NADH and $FADH_2$
- Electron carriers shuttle electrons down to electron transport chain, and the resulting $NAD^{+}$ and FADH can be recycled to be used again
■ Hydrogen atoms are split
● $\mathrm{H}_2-2 \mathrm{H}^{+}+2 e^{-}$
■ High-energy electrons are passed down a series of protein carrier molecules that are embedded in the cristae
● Some proteins include NADH dehydrogenase and cytochrome C
■ The electrons travel down the electron transport chain until they reach the final acceptor, oxygen
● Oxygen pulls the electrons through the chain due to its electronegativity and then combines with them and hydrogen to create water
● Allows For a gradual release of energy rather than a sudden, explosive one - Chemiosmosis
■ The energy released from the ETC is used to pump hydrogen ions across the inner mitochondrial membrane from the matrix into the intermembrane space
● Creates pH/proton gradient
● Potential energy created from gradient is responsible for the production of ATP - Flow back in through ATP synthase and this movement provides the energy necessary to produce ATP
- $ADP + P_i ⟶ATP$
