The state treasurer shall receive and keep, as provided by law, all the moneys of the state not expressly required by law to be received and kept by some other person; disburse the state moneys upon warrants drawn on the treasury according to law, and within the time limited in the constitution, and not otherwise, except that no warrant shall be required when the state treasurer is withdrawing state moneys from a bank account, demand or time, either for the purpose of transferring such moneys to another bank account, demand or time, or for the purpose of investing such moneys in obligations of the United States as authorized by law; keep a just and true account of all funds and appropriations made therefrom by law, and the disbursements made thereunder.