Image encryption is essential to keep images secure either in personal devices or over the cloud drives. Various robust image cryptosystems have been implemented during the past decades to keep the encrypted images far from illegal decryption by eavesdroppers. Biological sequences contain high density information that introduce new challenges and opportunities to traditional cryptography. This article presents a novel image cryptosystem, namely Image-to-Protein (I2P), that is based on successively encoding the image pixels into sequences of symbols analogous biological DNA and Protein sequences, and then scrambling these sequences into frequent and non-frequent patterns which in turn are binary encoded into the encrypted file. The proposed cryptosystem has been applied on experimental grayscale and color images. The large key space and the complicated Protein encoding operations guaranteed resistance to many known cryptographic attacks. Furthermore, the biological encoding of the plain image pixels resulted in high similarity that achieved noticeable lossless compression when compressed using known text compression techniques.