From Memory Alpha:
A typical transport sequence began with a coordinate lock, during which the destination was verified and programmed, via the targeting scanners. Obtaining or maintaining a transporter lock enables the transporter operator to know the subject's location, even in motion, allowing the beaming process to start more quickly. This is an essential safety precaution when a starship away team enters a potentially dangerous situation that would require an emergency beam-out.
A transporter lock was usually maintained by tracing the homing signal of a communicator or combadge. When there was a risk that such devices would be lost in the field or are otherwise unavailable, personnel could be implanted with a subcutaneous transponder before an away mission, to still provide a means to maintain a transporter lock. Alternatively, sensors could be used to scan for the biosign or energy signature of a subject, which could then be fed into the transporter's targeting scanner for a lock.
Next, the lifeform or object to be beamed was scanned on the quantum level, using a molecular imaging scanner. At this point, Heisenberg compensators took into account the position and direction of all subatomic particles composing the object or individual and created a map of the physical structure being disassembled, amounting to billions of kiloquads of data.
Simultaneously, the object was broken down into a stream of subatomic particles, also called the matter stream. The matter stream was briefly stored in a pattern buffer while the system compensates for Doppler shift to the destination.
The matter stream was then transmitted to its destination across a subspace domain. As with any type of transmission of energy or radiation, scattering and degradation of the signal must be monitored closely. The annular confinement beam (ACB) acted to maintain the integrity of the information contained in the beam. Finally, the initial process was reversed and the object or individual was reassembled at the destination.
This is basically stating that the bio-matter being transported is converted from regular matter into subatomic particles (possibly into energy itself) and then reconfigured back into it's proper 'pattern' at the new location.
So, the data being transmitted in the stream would only be the pattern after the initial scan, eveything else would be the matter (or energy) from the original bio-matter.