Fermentation, Aerobic and Anaerobic Respiration
Products of krebs cycle
2 ATP, 6 NADH, and 2 FADH2
Products of glycolysis
2 pyruvate, 4 atp (two extra from before) and 2 NADH
Cellular respiration efficiency
About 40% of the energy in a glucose molecule is transferred to ATP during cellular respiration, making about 38 ATP molecules
Three stages of cellular respiration
Glycolysis(breaks down glucose into two molecules of pyruvate). The citric acid cycle (completes the breakdown of glucose). Oxidative phosphorylation(accounts for most of the ATP synthesis)
Proton-motive force
H+ gradient, The energy stored in a H+gradient across a membrane couples the redox reactions of the electron transport chain to ATP synthesis
Electron transport chain
NADH passes the electrons to this in cellular respiration. Unlike an uncontrolled reaction, it passes electrons in a series of steps instead of one explosive reaction. O2 pulls electrons down the chain in an energy-yielding tumble. The energy yielded is used to regenerate ATP
First step of citric acid cycle
The acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate, forming citrate
Fat vs Carbohydrate energy storage
a gram of oxidized fat produces twice as much ATP than a gram of oxidized ATP
ATP synthase
a nanomachine, after electron transport chain builds H+ gradient, H+ moves back into mitochondrial matrix through chemiosmosis and this exergonic glow of protons happens through this channel.
Types of fermentation
alcohol fermentation and lactic acid fermentation
Fermentation vs Aerobic and Anaerobic respiration
all uses glycolysis and all use NAD+ as an oxidizing agent. In fermentation, pyruvate is the final electron acceptor. In Aerobic, oxygen is. In anaerobic, another molecule is (i.e. sulfate). Respiration produces 32-34 ATP per glucose while fermentation produces only 2
Glycolysis
anaerobic process, happens in cytoplasm, "splitting of sugar" breaks down glucose into two molecules of pyruvate. Glycolysis occurs in the cytoplasm and has two major phases:Energy investment phase and Energy payoff phase
Beta oxidation
breaks down fatty acids and yields acetyl CoA
Cytochromes
carry electrons down electron transport chain in oxidative phosphorylation
Obligate anaerobes
carry out fermentation or anaerobic respiration and cannot survive in the presence of O2
Oxidative phosphorylation
chemiosmosis couples electron transport to ATP synthesis. Generates the most ATP in cellular respiration because it is powered by redox reactions, almost 90%.
Citric acid cycle
completes the energy-yielding oxidation of organic molecules. The pyruvate molecules made by glycolysis is oxidized (O2) making acetyl coenzyme A (acetyl CoA) and CO2 as a byproduct. And NADP+ is reduced. 2 ATP, 6 NADH, and 2 FADH2 generated. Takes place in mitochondrial matrix
Aerobic respiration
consumes organic molecules and O2 and yields ATP
Fermentation
couples with glycolysis or anaerobic respiration to produce ATP. Uses substrate-level phosphorylation instead of an electron transport chain
Other seven steps of citric acid cycle
decompose the citrate back to oxaloacetate, making the process a cycle
Cellular respiration
glucose is oxidized and reacts with 6 oxygen resulting in 6 carbon dioxide, 6 H2O, and energy
What are fats digested to?
glycerol (used in glycolysis) and fatty acids (used in generating acetyl CoA)
Substrate-level phosphorylation
in glycolysis and citric acid cycle
Fermentation
is a partial degradation of sugars that occurs without O2
Anaerobic respiration
is similar to aerobic respiration, but when it uses an electron transport chain the electron acceptor is not oxygen.
Electron transport chain in oxidative phosphorylation
located in cristae of mitchondrion. Electron carriers alternate reduced and oxidized states. Passed through a number of proteins such as cytochromes. Electrons drop in free energy as they go down and finally passed to O2 to make water
Cristae
location of etc used in oxidative phosphorylation
3 reasons for inexact ATP yield in cellular respiration
phosphorylation and redox rxns not directly coupled, so NADH:ATP not a whole number. ATP yield varies depending on electron transport sys. PMF used to drive other kinds of work
Alcohol fermentation
pyruvate is converted into ethanol into two steps, releasing CO2 in the first
What must happen before the citric acid cycle can begin
pyruvate must be converted to acetyl CoA, which links the cycle to glycolysis
Lactic acid fermentation
pyruvate reduced to NADH forming lactate as an end product. 2 lactic acid and 2 ATP generated from 1 glucose, 2 ADP, and 2 phosphate. Final electron acceptor is pyruvate
NADH and FADH2
relay electrons extracted from food to the electron transport chain. They are electron carriers that donate electrons to the electron transport chain which powers ATP synthesis via oxidative phosphorylation
NADH
stored energy that is used to synthesize ATP.
Chemiosmosis
the use of energy in a H+ gradient to drive cellular work.
Facultative anaerobe
they can survive either y fermentation or cellular respiration, i.e yeast and many bacteria. Pyruvate is a fork in the metabolic road
