We know that early life on Earth evolved without it. This is when oxygen first appeared.
What is 2-3 billion years ago?
100
Within the mitochondria, each pyruvate is broken apart and combined with the coenzyme CoA to form this.
What is Acetyl CoA?
100
Mitochondria are specialized to carry out this process.
What is aerobic respiration?
100
At the end of the Krebs Cycle, energy from the chemical bonds of glucose is stored in diverse energy carrier molecules; ATP, NADH, and also these.
What are FADH2?
100
The organelle in all eukaryotic cells where stages 2 and 3 of aerobic respiration produce ATP.
What is mitochondrion?
200
The event that prompted Oxygen's arrival.
What is photosynthesis of bluegreen bacteria?
200
The Krebs Cycle begins by combining each Acetyl CoA with a four-carbon carrier molecule to make a 6-carbon molecule of this, which gives the Krebs Cycle its other name.
What is citric acid?
200
The inner membrane of mitochondria folds into this, dividing the organelle into three compartments.
What is cristae?
200
The primary purpose of the electron transport chain is to transport this from other carrier molecules to ATP.
What is energy?
200
Stage 2 of aerobic cellular respiration; a series of chemical reactions which completes the breakdown of glucose begun in stage 1, releasing more chemical energy and producing carbon dioxide.
What is the Krebs Cycle?
300
The levels of oxygen on Earth increased with the evolution of these.
What are land plants?
300
A series of chemical reactions take place in the Krebs Cycle which gradually release energy and captures it in these.
What are carrier molecules?
300
The three compartments of the mitochondria.
What are the intermembrane space, cristae space, and matrix?
300
In both photosynthesis and aerobic respiration, the energy lost in the process is harnessed to pump hydrogen ions into a compartment, creating this.
What is an electrochemical or chemiosmotic gradient?
300
The process of "splitting glucose" - stage 1 of aerobic cellular respiration and also the basis of anaerobic respiration; splits glucose into two 3-carbon pyruvates.
What is glycolysis?
400
The percentage of oxygen in our atmosphere today.
What is 21%?
400
This is required to drive the Krebs Cycle, but not actually consumed by the cycle's chemical reactions.
What is oxygen?
400
The compartment where the Krebs Cycle takes place.
What is the matrix?
400
After passing through the ETC, low energy electrons and low energy hydrogen ions combine with oxygen to form this.
What is water?
400
A series of molecules which accept and pas along energy-carrying electrons in small steps, allowing the energy lost at each transfer to be captured for storage or work.
What is the electron transport chain?
500
Pyruvate is created during glycolysis, and enters this organelle if oxygen is present.
What are the mitochondria?
500
At the conclusion of the Krebs Cycle, glucose has completely broken down and four molecules of this have been produced.
What is ATP?
500
This is embedded in the inner membrane of the mitochondria.
What is the electron transport chain?
500
The number of ATP produced in the last stage of cellular respiration.
What is 34?
500
The process in cellular respiration or photosynthesis which produces ATP using the energy of hydrogen ions diffusing from high concentration to low.