The focus of your research was to answer a specific question. While it may be interesting to you, it must be relevant to a larger body of research to have scientific value. It is critical that you are able to finish your thesis and tell anyone asking why what you did was important. Your thesis will begin with an introduction and end with a conclusion; place your research into a broad perspective in both these sections.
Your college or university will provide guidance for the structure of your thesis. However, your thesis will generally begin with a table of contents and be followed by a short introduction. Then one or more chapters will fill the bulk of your thesis, each representing a different research project or line of thought. A short conclusion section will follow the last of these chapters. You will also want to write an acknowledgment section where you thank the people who helped you throughout your graduate studies and sources of funding. You can place this either at the beginning or the end of your thesis.
Your thesis will either begin or end with an acknowledgment section. It is in this section you will thank members of your graduate committee, fellow graduate students, your major professor and even family members. Also give credit to people whose laboratory you used and sources of funding you received. Compile this list well ahead of time, and add to it as you remember individuals making sure not to leave anyone out.
Although writing a chapter for your thesis can be much different than writing a paper for publication in a peer-reviewed journal, it does not have to be. If your intent is publication, construct your chapters so they adhere to the guidelines of the target journal. Generally, papers will begin with an introduction and be followed with methods, analysis, results and discussion sections. Journal editors have an eye toward concise and focused writing. If you write your thesis tightly, submitting it to a journal should be seamless.