Alkenes and Alkynes Examples of naturally occurring alkenes Ethylene is a plant hormone that induces ripening in fruit a-pinene is the major component of turpentine B-carotene is an important dietary source of vitamin A and is responsible for the orange color of carrots CH3 Ethylene a-Pinene B-Carotene (orange pigment and vitamin A precursor) Alkenes and Alkynes Examples of naturally occurring alkenes ▪ Ethylene is a plant hormone that induces ripening in fruit ▪ a-pinene is the major component of turpentine ▪ b-carotene is an important dietary source of vitamin A and is responsible for the orange color of carrots