Drubin Lecture 25 - Drubin Lecture 25 Nuclear and Chromatin...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Drubin - Lecture 25: Nuclear and Chromatin Structure MCB 130 The Nucleus and Chromatin Structure 1 . Overall nuclear organization: Separation of nucleoplasm from cytoplasm in eukaryotes allows spatially separate processing of transcripts in nucleus before they are exported for protein synthesis (Figure 1). a) nuclear envelope (NE) – connected to ER; A double membrane system b) nuclear pores – route of mRNA transport. Nuclear pores provide passages through both membranes (figure 1). c) chromatin: DNA molecules are packaged with histones and nonhistone proteins as chromatin. (DNA 1/3 mass, histones 1/3, nonhistone chromosomal proteins 1/3) heterochromatin – more condensed, transcriptionally inactive, contains many middle repetitive and highly repetitive sequences, found near the nuclear envelope, is usually late replicating euchromatin – less condensed, actively transcribed genes, found in nuclear interior 2. The nucleus has specialized functional domains: a) nucleolus: site of ribosomal RNA synthesis The nucleolus is organized by a special domain on one of the chromosomes that contains rRNA genes (Nucleolar Organizer Region). It consists of a fibrillar central matrix, i.e. DNA, dense fibrillar cores, and a granular zone where ribosomal precursors are being assembled.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern