Em
To make the chord changes in the above progression easier, play the Em chord with your first and second fingers. This allows the use of pivot fingers between G to Em and Em to C.
A pivot can also be used between C and D7 and a slide finger between G and D7. Alternative fingering for any chord shape can be used to make chord progressions easier to play.
Rhythm Pattern
In this turnaround there are two chords in each bar. Use your first and second fingers as pivots when changing between C and Am.
Notice the similarity in sound in the Turnaround progressions above. They are the same progression but in two different keys.