Although 1 cent is the lowest amount for a click, Google takes its own percentage which in this case is 50%. 50% of 1 cent is 0.5 cents (or half a cent).
They get this for:-
hosting the ads sorting out which ads to show collecting the money from the advertiser paying the publisher other stuff
Obviously if you arrange ads yourself on a site you get more of the take. Generally % payouts vary with Google from ~ 50% up to 100% (although this is extremely rare). It all depends on how much your site costs Google.