Cell lecture 1
Terms
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- What is special about eukaryotic cells vs prokaryotic?
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eukaryotic Contains
Nuclear envelope
histones
membrane bound organelles
prokaryotic is only bacteria - How do nuclei in normal tissue appear vs cancerous?
- normal is uniform in size and morphological features where cancerous are irregular
- What is fluid in nucleus called?
- nucleoplasm
- What is unique about the nuclear envelope?
- it is a double membrane of two phospholipid bilayer
- What is the space between nuclear envelope?
- perinuclear cisterna or perinuclear space
- Explain the surface of nuclear envelope
- it is covered with ribosomes and forms attachments with rough endoplasmic reticulum
- what helps to stabilize the nuclear envelope?
- fibrous lamina or nuclear lamina
- What is the function of nuclear lamina?
- regulates chromatin, stabilizes nuclear envelope
- What does fibrous lamina do during mitosis?
- breakdown the nuclear envelope through phosphorylation
- What structures allow fluid flow in/out of the nucleus?
- Nuclear Pore Complexes
- What is a nuclear pore complex derived from?
-
Nucleoporins make the octagonal structure
GP210 anchors - How do large molecules enter through Nuclear Pores? what must they posess?
- The molecule must have the nuclear localization signal, they bind to a chaperone protein that guides them to and NPC where GTP is used for active transport.
- What is the nucleosome made of?
- 146 DNA base pairs wrapped around histones with 48 base pair linker regions
- What is chromatin made of?
- Nucleosomes
- What is the structure of chromatin?
- Solenoid (helix coil of wire)
- What is unpacked chromatin called and how does it show up in a stain? why is it unpacked?
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euchromatin
it is poorly colored
It is unpacked for transcription (active form) - What is packed chromatin called and how does it show up in a stain? why is it packed?
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Heterochromatin
dark in stain
not actively transcribing it is well protected - What is the highest packed chromatin?
- chromosomes ready for mit/meiosis
- What structures are in the nucleolus?
-
pars amorpha
nucleoleonema
- pars fibrosa
- pars granulosa - What does the pars amorpha do?
- contains Nuclear organizer DNA - sequences of bases that code for rRNA
- What does pars fibrosa consist of?
- newly synthesized primary transcripts of rRNA and associated proteins
- what does pars granulosa contain?
- maturing ribosomal subunits undergoing assembly to be exported to cytoplasm
- What are the 4 main phases of the cell cycle
- mitosis, interphase, Gap 0 (prep for mitosis), Gap terminal differentiated - nondividing cells
- what are the phases of interphase and what occurs in each?
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1. Gap 1
just RNA/protein synthesis no DNA
Grows to parental size
ongest phase
2. Synthesis
DNA synthesis and replication
3. Gap 2
damaged DNA repaired
create tubulin for spindle
Maturation promoting factor - what does Maturation promoting factor do?
-
disentegrate nuclear envelope
condense chromosomes - What are the steps of mitosis?
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Prophase
metaphase
anaphase
telophase - What happens in prophase?
-
chromatin coils form chromosomes
nucleoli disentegrate
mitotic spindle forms - what happens in metaphase?
-
nuclear envelope disentegration
chromosomes line up equator
chromosome splititng into sisters
spindles attach to centromeres - what happens in anaphase?
- sister chromatids separate and move to opposite poles
- what happens in telophase?
-
nucleoli and nuclear envelopes reappear as components of two separate nuclei
purse string constriction
cytokinesis - ends mitosis