Help with my 11 year old daughter?

My daughter is almost 11, just finishing 5th grade. I just dont know what to do with her. She acts like I am so embarrassing to her, she isnt very nice to me, she uses an annoyed tone of voice with me and rolls her eyes over the simplest things, she leaves empty wrappers all over the place, she loses valuable things, like her iPod touch she lost 3 times in one day. As a result, I took it away from her for several days. Last night I let her use my camera to make videos and now she cant find it, cant remember where she put it, and I need it tomorrow to take pictures at the elementary school graduation. I am constantly telling her to pick up after herself, and she does it reluctantly but then she doesnt remember the next time. Her behavior is disrepectful and hurtful, and nothing seems to change it. I have punished her, taken things away from her, I have tried to talk to her and explain my feelings and reason with her, I have tried to give her more responsibilities, nothing works. She does very well in school, she has a great group of friends and she is involved in sports. And she wasnt always like this, just in the last year or so. I guess its puberty kicking in but that shouldnt be an excuse. Its like she has no respect for me or for her surroundings. Help.