A phosphate group is a part of a molecule (i.e. group) with the formula PO4.
Depending on the molecule it is part of it can be either inorganic phosphate or organic phosphate.
Phosphate groups are essential to many biochemical processes (e.g. ATP for energy storage, phosphorylation of DNA to inhibit/enable gene expression).
There are three phosphate groups in a molecule of adenosine triphosphate (ATP).
between phosphate groups
There are two phosphate groups in one molecule of ADP.
The DNA backbone, are made of alternating sugars and phosphate groups.
Two, as it now becomes adenosine diphosphate. when it has three it is adenosine triphosphate.
Adenosine Triphosphate (ATP) has three Phosphate Groups, hence Triphosphate.
Between the phosphate groups
A negative charge, as do all phosphate groups.
The original molecule has two phosphate groups attached.
There are three phosphate groups in an ATP molecule. Go on to Google images and type in ATP or adenosine triphosphate. Look for a picture that contains chemical symbols and lines. Now, commonly on the right hand side you will see the bulk of the picture. On the left should be a line with P's and O's in the middle of it. The P's of course are the phosphates. The P closest to the bulk is called the alpha phosphate. then working out you have the beta phosphate and then the gamma phosphate. The symbols for these phosphates are the Greek letters for Alpha, Beta, and Gamma.
High energy bonds in ATP are found between the second and third phosphate groups. This bond is called a phosphoanhydride bond and contains a large amount of chemical energy due to the repulsion between the negatively charged phosphate groups.
An ATP molecule has an extra phosphate group compared to an ADP molecule. This is because ATP has 3 phosphate groups as where ADP only has two phosphate groups.