Among the features of GNOME 3 is an embedded screen recorder.
Link: GNOME screencast
One restriction is the fact it has a default recording duration of 30 seconds. Do not worry as we can adjust this.
Note: We will be increasing the duration to 60 minutes.
Open a terminal and enter:
gsettings set org.gnome.settings-daemon.plugins.media-keys max-screencast-length 7200
For other durations greater than a minute, use formula: 60 * number_of_minutes.