Lecture1 Flashcards
basic set of organelles
Nucleus, Ribosomes, Endoplasmic reticulum, Golgi, Lysosomes, Mitochondria & Peroxisomes
Components of cell nucleus
Nuclear envelope Nuclear lamina Nuclear pores Nucleolus Nucleoplasm
Faces the nucleoplasm, and is in contact with the nuclear lamina
- Function as a scaffold stabilizing the nuclear envelope
Inner nuclear membrane
faces the cytoplasm and continues with endoplasmic reticulum
Outer nuclear membrane
Thin, sheet-like meshwork beneath the inner nuclear membrane
Nuclear Lamina
What is nuclear lamina made up of
Lamin A&B
What does Lamin A mutation cause?
Hutchinson-Gilford Progeria syndrome (preaging)
Roles of nuclear lamina
Scaffold for nuclear envelope, chromatin & Nuclear pores
A complex that spans inner and outer nuclear membrane, and allows transport of molecules between nucleus and cytoplasm
Nuclear Pore Complex (NPC)
The site of ribosome production (ribosome factory)
Nucleolus
3 Zones of nucleolus
- Fibrillar center
- Fibrillar material
- Granular material
Staining of fibrillar center
pale staining
Role of fibrillar center
Contain DNA loops of rRNA genes for creating ribosome
Staining of fibrillar material
Dark staining
Role of fibrillar material
transcription of rRNA genes
Role of granular material
initial ribosomal assembly occurs
2 types of chromatin
Euchromatin & Heterochromatin
Staining of euchromatin and its transcription state
Light staining, and active transcription
Staining of heterochromatin and its transcription state
Dark staining, and less transcriptionally active
Complex of DNA and histones
Beads on a string chromatin
Nucleosome
When nucleosomes are packed together, it forms …
30-nm chromatin fiber
When 30-nm chromatin fiber loosely arrange, it becomes
Euchromatin
When Euchromatin and heterochromain pack together, it forms
Chromosome
Specific specialized nucleotides sequences in all chromosomes (3)
- Centromere
- Telomere
- Replication origin
Centric heterochromatin
Holds sister chromatids together
Site of kinetochore formation
Centromere