Test 2 Respiration, Fermentation, & Photosynthesis Flashcards
Respiration
An efficient method of producing energy that involves the oxidation of organic molecules, the passage of an electron down an electron transport chain, and the harvesting of energy via chemiosmosis
Aerobic respiration
A type of cellular respiration in which oxygen is the terminal electron acceptor.
A type of cellular respiration in which something other than oxygen is the terminal electron acceptor.
Anaerobic respiration
What is the major difference between aerobic and anaerobic respiration?
The terminal electron acceptor. Aerobic respiration uses oxygen; anaerobic respiration uses something other than oxygen.
fermentation
An inefficient method of extracting energy from organic molecules that involve only substrate-level phosphorylation, or the enzymatic transfer of a phosphate group from a high-energy substrate to ADP, forming ATP
True or false: In fermentation, the electron acceptor is endogenous
True. This means that is created by the cell and is commonly found within the cell. It does not have to come from outside the cell.
True or false: The proton motive force is only used for ATP synthesis
False. The proton motive force is used for a number of reasons, including ATP production, active transport mechanisms, and driving bacteria flagella.
Substrate-level phosphorylation
The enzymatic transfer of a phosphate group from a high-energy substrate to ADP, forming ATP.
Oxidative phosphorylation
The use of the reducing power of NADH and FADH2 to create ATP with the use of a proton motive force.
Amphibolic pathway
A pathway that can be simultaneously anabolic and catabolic.
What are some examples of amphibolic pathways?
Glycolysis, the TCA cycle, and the pentose-phosphate pathway
Glycolysis
The metabolic pathway that turns a six-carbon sugar (glucose) into two three-carbon sugars (pyruvate).
Embden-Meyerhof Pathway
The most common glycolytic pathway; this is usually what you are referring to when you say ‘glycolysis.’
Where does the Embden- Meyerhof pathway occur?
In the cytoplasmic matrix
TCA cycle
Also called the Krebs cycle or the citric acid cycle, this is the process that involves eight steps that oxidize inorganic acids and reduce NAD+ and FAD+, letting off NADH, FADH2, and CO2, and producing a small amount of ATP.
What are the products of the TCA cycle for each acetyl- CoA molecule?
3 NADH, 1 FADH2, 1 GTP, and 2 CO2
The reduction of NAD+ forms ________
NADH
True or false: Iron is essential to the transfer of electrons via cytochromes in the electron transport chain.
True
Electron transport chain
- Complex made of several proteins (mostly cytochrome proteins)
- Forms a long chain along the mitochondrial inner membrane (in eukaryotes) or plasma membrane (in prokaryotes)
3, Pass down electrons to acceptors that are more electronegative. - Uses energy released to pump protons across the membrane.
Chemiosmosis
Occurs when ATP synthase uses the free movement of protons across a membrane to power the phosphorylation of ADP to form ATP
The chemiosmotic hypothesis explains…
Oxidative phosphorylation
In the electron transport chain, electrons flow from carriers with more_________ E0 to carriers with more _________ E0
Negative; positive
The reduction of the terminal electron acceptor in aerobic respiration produced ____________
water
In eukaryotes, the electron transport chain is located….
along the inner mitochondrial membrane.
In prokaryotes, the electron transport chain is located…
along the plasma membrane
As electrons move down the electron transport chain in eukaryotes, protons are pumped…
From the mitochondrial matrix to the intermembrane space.
Proton-motive force
The force created by the concentration of protons on one side of a biological membrane. This force can be used to create ATP via chemiosmosis. It can be used in active transport to power bacteria flagella.
ATP synthase
The enzyme that uses the proton motive force to synthesize ATP during chemiosmosis
What are some differences between prokaryotic and eukaryotic electron transport chains?
Prokaryotic electron transport chain are shorter, branched, contain different electron carriers, and exist along the plasma membrane (rather than along the inner mitochondrial membrane)
True or false: Oxidative phosphorylation is responsible for the majority of ATP production during aerobic respiration.
True
Aerobic respiration can produce a maximum of _____ ATPs per glucose molecule. The actual yield is usually lower–perhaps around _____ molecules of ATP per glucose molecule.
38; 30
Beta-oxidation
A process in which fatty acids are broken down into fragment that can be converted into acetyl-CoA, which can then be fed into the Krebs cycle.
SeO4-2 is an example of a final electron acceptor in ___________ respiration
Anaerobic
One reason why aerobic respiration produces more ATP than anaerobic respiration is that oxygen’s reduction potential (E0) is (low/high)
High
Nitrogen fixation
The reduction of atmospheric nitrogen to ammonia
Denitrification
The reduction of nitrate into nitrogen gas.
Nitrification
The oxidation of ammonia to nitrate.
True or false: Fermentation harnesses energy using the proton motive force.
False. It uses only substrate-level phosphorylation; it does not involve the electron transport chain or oxidative phosphorylation, so it does not harness energy using the proton motive force.
Pentose phosphate pathway
A pathway for converting glucose to pyruvate that can occur aerobically or anaerobically and can occur at the same time as the glycolytic pathway.
What is a commonality of the Entner- Duodoroff, pentose-phosphate, and Embden- Meyerhoff pathways?
They all convert glucose to pyruvate
Photosynthesis
An anabolic process in which light energy is converted to chemical energy, which is storied in the bonds of organic molecules such as glucose.
Oxygenic Photosynthesis
A type of photosynthesis that produces oxygen as a byproduct. Eukaryotes and cyanbobacteria use this kind of photosynthesis.
Anoxygenic photosynthesis
A type of photosynthesis that does not produce oxygen as a byproduct. Archaea and Bacteria (other than cyanobacteria) use this kind of photosynthesis.
Light reactions
The first step in photosynthesis, during which light energy is converted to chemical energy in the form of ATP and NADPH.
Dark reactions
The second step in photosynthesis , during which the reducing power of ATP and NADPH is harnessed, and the energy is put into long-term storage molecules, such as glucose, sucrose, and starch.
Cholorphyll
The primary photosynthetic pigment found in plants, algae, and cyanobacteria.
Bacteriorhodopsin
A pigment found in certain groups of bacteria and archaea. This pigment directly acts as a proton pump, so it can produce energy without the electron transport system.
What is a commonality of anaerobic respiration, fermentation, aerobic respiration, and photosynthesis?
They all involve the production of ATP
