It is found, determined, and declared that the carrying out of the purposes of the authority as defined in this article is in all respects for the benefit of the people of this state and that the purposes are public purposes; that the authority will be performing an essential governmental function in the exercise of the powers conferred upon it by this article; and that the activities authorized in this article will develop and promote trade, commerce, industry, and employment opportunities to the public good and the general welfare and promote the general welfare of the state. The state covenants with the holders of the revenue bonds that the authority shall be required to pay no taxes or assessments of the state or its municipalities or political subdivisions upon any of the property acquired or leased by it, or under its jurisdiction, control, possession, or supervision or upon its activities in the acquisition, construction, operation, or maintenance of the facilities erected or acquired by it, including the purchase of tangible personal property for such purposes, or any fees, rentals, or other charges, for the use of such facilities, or any other income received by the authority. Further, the state covenants that the revenue bonds of the authority, their transfer, and the income therefrom shall at all times be exempt from taxation within this state by the state or its municipalities or political subdivisions. Any exemption from taxation provided by this Code section shall not include exemption from sales and use taxes on sales made by the authority in transactions or to persons not otherwise exempt therefrom.