When I click on a photo in Iphoto a

In your Pictures folder there should be an icon called iPhoto Library. If you then hold down Control while selecting the icon with your mouse, you should get a menu with the item Show Package Contents. A window should open in which the two folders Modified and Originals, should appear (among a number of other items). In Originals, your photos are grouped by year. If you've set up the date on your camera properly, you should be able to find your photo from there.