The synthesis of ATP, the cells energy currency, involves a number of steps performed by a tiny molecular motor, found in the mitochondrial membrane, called ATP synthase.
1. Binding of ADP and the phosphate to ATP synthase
2. Formation of the new high energy phosphate-phosphate bond between the ADP and phosphate
3. Releasing the newly made ATP
ATP synthase - shown here in 3D with each protein shown a different colour
Exploring ATP synthase in 3D
- left mouse button to rotate the protein model.
- middle mouse button or scroll wheel to zoom (option-click on a Mac)
- right mouse button for more options and information (control-click on a Mac).
Have a go yourself now ==>
The ATP synthase molecule
ATP synthase is built up of different groups of proteins: the F0, the F1 and the axel - each with a important role.
The contains alpha (shown in light blue) and beta (shown in dark blue) protein chains. It also binds the adenosine diphosphate (ADP) molecules and the adenosine triphosphate (ATP) . See if you can zoom in on the ATP identify how many phosphates (atoms shown in orange) are found.
Q1: Where is the F1 region located within the ATP synthase, and what is its role?
Q2: How many ATP and ADP can you find and how is related to the number of protein chains in the F1 motor?
The rotates putting the motor into three different conformations as the ADP binds, the phosphate bond is formed and the ATP being released.
is a circular rotor that is formed of alpha helices that sit in the mitochondrial membrane. The hydrogen ions travel around the circular F0 motor, and turning the rotor in the process, much like a water wheel. The hydrogens are passed alone a chain of aspartic acid residues (amino acids) in the F0 motor, and then transferred to an arginine amino acid. The arginine passes the hydrogen to the rotor, which turns all the way around. Then the hydrogen is then passed to the opposite side of the membrane.
To the right is a structure of ATP synthase shown using the Jmol viewer within Proteopedia.
Click '>here</scene> for a view where the different components are coloured differently? See how many you can identify
Q3: What is the location and role of the FO region?
ATP synthase is an example of a molecular motor.
Use the Structure to answer the questions below.
Q4: How many phosphates does ATP have?
Q5: How many phosphates does ADP have
Key Terms
Aspartic acid
ATP
AMP
ATP synthase
