Chapter 6 Flashcards
What is Bioenergetics?
The application of thermodynamic principles to organism and biological systems. The fundamental characteristics of all living things is the ability to carry out metabolism.
What are the four parts of cellular respiration and where do they occur?
Glycolysis (cytosol), breakdown of pyruvate (mitochondria matrix), Krebs Cycle (mitochondria matrix), Electron Transport Chain (Mitochondria Inner Membrane)
What is the input for glycolysis?
A 6-carbon glucose and 2ATP.
What happens in glycolysis?
Glucose is oxidized, creating 2NADH and a net of 2 ATP and 2 3-carbon Pyruvate. Exergonic.
How does glycolysis make ATP?
By Substrate Level Phosphorylation. ADP phosphate transfer.
What is produced through the breakdown of pyruvate?
CO2 and NADH. CoA attaches to the remaining 2 carbons to produce Acetyl-CoA.
Output of the Krebs Cycle
Per one Acetyl-CoA:
2 CO2 released, 3 NADH produced, 1FADH2 produced, 1 ATP produced
How is the energy stores after the Krebs Cycle?
In NADH and FADH2. It is released through the ETC, with oxygen being the terminal electron acceptor. Exergonic.
What does the ETC do?
Moves electrons from NADH/FADH2 to O2 to make H2O; moves H+ ions from the matrix to the inner membrane space (low to high concentrations); makes a lot of potential energy.
What is ATP Synthase?
It uses 3 H+ to make 1 ATP from ADP, the energy comes from the concentration gradient as hydrogen returns to the matrix.
What is Chemiosmotic Theory?
The ATP synthesis from the ATP synthase of 3H+ to make one ATP from ADP.
What are Strict Anaerobes?
Organisms unable to live in the presence of oxygen.
What are Facultative Anaerobes?
Organisms able to live in both oxygenic and non-oxygenic environments.
What is Alcohol Fermentation?
In the absence of O2, yeast ferments glucose into ethonol - only 2ATP are produced.
What is Lactic Acid Fermentation?
During Anaerobic respiration, muscle O2 depeltion leads to this. 2 ATP are produced; no CO2 released.
Which of the following has less energy:
ADP vs ATP
NAD+ vs NADH
CO2 vs C6H12O6
Oxidized has less energy than reduced; ADP, NAD+, CO2.
Muscle Energetics
Muscles can respire both aerobically and anaerobically; under high power demand they will be anaerobic, under low demand they will be aerobic.
What is Gluconeogenesis?
The reverse of glycolysis.
What are some Respiratory Proteins?
Rotenone (kills insects and fish), Cyanide (inhibits oxygen binding), Dinitrophenol (short circuts ETC)
What is Cellular Respiration?
The process by which energy-rich molecules are broken down to produce energy in the form of ATP
Why is food a good source of energy?
Because of the abundance of C-H bonds. Oxygen bonds contain less potential energy. C-H bond electrons can easily be removed to do work, because electrons farther from the nucleus contain more energy.
Why is oxygen gas a good terminal electron accepter?
Because of its high affinity for its electrons.
What are Dehydrogenases?
Groups of enzymes that facilitate the transfer of electrons from food to a molecule that acts as transport. NAD+, FAD.
Which is oxidized and which is reduced:
NAD+, NADH
Oxidized, reduced.
NAD+ + 2e- + H NADH
