AP Biology -Chapter 7: Cellular Respiration

Fermentation

Fermentation

consists of glycolysis plus reactions that regenerate NAD+, which an be reused by glycolysis

Aerobic Respiration

consumes organic molecules and O2, yields ATP

Cellular Respiration

oxidizing glucose, cells consume energy from organic molecules to regenerate ATP, which powers work

Equation for aerobic respiration

C6H12O6 + 6O2 --> 6CO2 + 6H2O + Energy

Oxidation reduction reaction

electrons are ripped off of molecules to give to NAD+ to form NADH

NAD+

the electron carrier in cellular respiration, reduced to form NADH during glycolysis and the Krebs Cycle

Glycolysis

Glucose is split into two 3-carbon molecules of pyruvate, and NAD+ becomes NADH. Two ATP are formed by substrate-level phosphorylation, and can occur whether or not O2 is present

Citric Acid Cycle

The Acetyl CoA enters the Krebs cycle and has to combine with 4-carbon oxaloacetate (that will need to be regenerated), which forms citric acid. The Acetyl CoA is oxidized, 2CO2 is breathed out, and more electrons are ripped off and it is given to the electron carriers to form NADH and FADH2. ATP is produced through substrate-level phosphorylation.

Oxidative phosphorylation

accounts for most of the ATP generated by cellular respiration; involves the transfer of inorganic phosphates to ADP

Substrate-level phosphorylation

an enzyme with a phosphate group takes it from one molecule and gives it to ADP

Acetyl CoA

Before pyruvate can go into the Krebs cycle, it is oxidized. One carbon is lost because it is exhaled out at CO2. The two-carbon molecule is oxidized and NAD+ becomes NADH.

Cytochromes

Membrane bound proteins that contain a heme prosthetic group and are essential for electron transport

ATP Synthase

The complex protein that is used to transport H+ back across the membrane

Chemiosmosis

The use of energy in a H+ gradient to drive cellular work

Proton motive force

Created by pumping protons out by the respiratory chain complexes. Used to translocate protons through ATP synthase to form ATP

Alcohol Fermentation

Produces ethanol and CO2

Lactic Aid Fermentation

Pyruvate is reduced and turned into lactic acid in the muscles

Facultative Anaerobes

Can survive using either fermentation or cellular respiration i.e. yeast and bacterias

Obligate anaerobes

Cannot survive in the presence of O2

Steps of cellular respiration

Glycolysis, oxidation of pyruvate, Krebs Cycle, and oxidative phosphorylation

reactants of glycolysis

Glucose, NAD+, ATP, ADP

Products of glycolysis

Pyruvic acid, ATP, NADP

Reactants of oxidation of pyruvate

Pyruvic acid, NAD+

Products of the oxidation of pyruvate

Acetyl CoA, NADH, CO2

Reactants of citric acid cycle

Acetyl CoA, oxaloacetate, NAD+, FAD

Products of citric acid cycle

Citric acid, NADH, FADH2, CO2, oxaloacetate, ATP

Reactants of oxidative phosphorylation

NADH, FADH2, ADP, O2

Products of oxidative phosphorylation

ATP, H2O, FAD, NAD+

Reactants of alcoholic fermentation

Sugar

Products of alcoholic fermentation

Ethanol, CO2, NAD+

Reactants of lactic acid fermentation

Pyruvate, NADH

Products of lactic acid fermentation

Lactic acid, NAD+