celluar resparation + fermentation

celluar respiration

• when cells break down glucose using oxygen to produce ATP

• make 338 ATP

Aerobic respiration

needs oxygen to occur (EX: cellular respiration)

Anaerobic respiration

does not need oxygen to occur (EX: fermentation, yeast, muscle tissue, bacteria, archaea)

steps of celluar respiration

1. Glycolysis

1a. Pyruvate Oxidation

2. Krebs Cycle

3. Oxidative Phosphorylation (in two steps: 1. Electron Transport Chain, 2. Chemiosmosis)

electron carriers during celluar respiration (+ function)

• NADH, FADH2

• transport high-energy electrons broken down from glucose (during glycolysis) to the electron transport train

• after finishing cellular respiration, they become NAD+ and FAD and are put back into glycolysis

Glycolysis (func, location, inputs, outputs)

• ONLY Anaerobic step (will happen no matter what)

• FUNC: to break down Glucose into Pyruvate to be used inside the mitochondria

• LOC: Cytoplasm (outside mitochondria)

• INPUTS: Glucose

• OUTPUTS: 2Pyruvate, 2NADH

Pyruvate Oxidation (func, location, inputs, outputs)

• Aerobic — if there is no oxygen, then the process goes into fermentation

• FUNC: to convert Pyruvate to Acetyl-CoA to be used during the Krebs Cycle

• LOC: Mitochondrial Matrix (middle of mitochondria)

• INPUTS: 2Pyruvate

• OUTPUTS: 2Acetyl-CoA

Krebs Cycle (func, location, inputs, outputs)

• Aerobic

• FUNC: finishes the process of breaking down glycose/pyruvate to produce high amounts of electron carriers (NADH, FADH2) for Oxidative Phosphorylation

• LOC: Mitochondrial Matrix (middle of mitochondria)

• INPUTS: Acetyl-CoA

• OUTPUTS: 6NADH, 2FADH2

Oxidative Phosphorylation (func, location, inputs, outputs)

• Aerobic

• FUNC: the electron carriers (NADH, FADH2) turn ADP into ATP

• LOC: Mitochondrial inner membrane

• INPUTS: NADH, FADH2, ADP

• OUTPUTS: 34ATP

Final electron acceptor for celluar respiration (+ function)

• Oxygen

• While H+ ions (NAD+ and FAD) move through ATP synthase, they become used up/ “trash”

  • NAD+ and FAD —> NADH and FADH2

• an oxygen atom bonds (accepts) with a H+ ion to turn NADH and FADH2 back into NAD+ and FAD to be inputs again in the cycle

• allows the cellular respiration process to continue

• produces water as a byproduct

• if there is no oxygen to accept/bond to the H+ ions, celluar respiration stops, no ATP is made, cells do not have enough energy to survive

Fermentation

• When it is not possible to continue cellular respiration (due to a lack of/not enough oxygen), the body gets ATP from fermentation

• to create NAD+ energy

• Short-term/last resort survival solution to keep the body surviving (not reach total ATP shutdown/death)

• not as efficient but shorter process (survival > efficiency)

• make 2 ATP

times of use (fermentation)

• biologically: muscle cells during intense exercise, microorganisms in oxygen-poor environments

• artificially: food production (bread, yogurt, beer)

Fermentation types

Lactic Acid Fermentation, Alcoholic Fermentation

steps of fermentation

1. Glycolysis (of celluar respiration)

2. NAD+ Regeneration

Glycolysis (inputs, outputs)

• INPUTS: Glucose

• OUTPUTS: 2Pyruvate, 2NADH

NAD+ Regeneration (function, inputs, outputs)

• FUNC: to take NADH from glycolysis and use it to reduce pyruvate, turning the NADH into NAD+ (which is used as an input for glycolysis so the cycle can continue)

• INPUTS: 2 NADH, 2 Pyruvate

• OUTPUTS (for animals): 2NAD+, 2lactate (AKA: lactic acid, byproduct)

• OUTPUTS (for plants/bacteria/yeast): 2NAD+, 2ethanol (byproduct) + 2CO2

final electron acceptor for fermentation

• Pyruvate

• turns NAD+ back into NADH to allow the fermentation process to continue

Lactic Acid fermentation

• only occurs in animal cells + certain bacteria

• Glucose —> Pyruvate —> Lactic Acid

• Lactic acid bulidup = muscle “burning”, cramping, fatigue

• Severe lactic acid bulidup (lactic acidosis) = GI issues, shortness of breath, neurological dysfunction, Trachcardia (from VERY VERY extreme workouts)

Alcoholic Fermentation (artificial fermentation)

• occurs in plants + yeast

• has an extra step: Pyruvate Conversion

• Glucose —> pyruvate —> acetadehyde —> ethanol (CO2 byproduct)

  • Pyruvate is oxidized into Acetaldehyde enzyme —> then reduced by NADH into ethanol

• Used in alcoholic beverages: glucose is taken from grapes, malted barley, or sugarcane to produce ethanol (alcohol), and CO2

• Used in baking: yeast