Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to...
-
Upload
alaina-griffith -
Category
Documents
-
view
215 -
download
0
Transcript of Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to...
![Page 1: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/1.jpg)
Nucleus
General features of nucleiA-Major components
1-nuclear envelope2-Nuclear Sap
3-one to several nucleoli4-Nuclear chromatins
![Page 2: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/2.jpg)
B-nuclear function
1-In heredity(store house for gentic information)
2-Cell division(nucleus regulates the processes of cell division
3-Controlling all cellular function
![Page 3: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/3.jpg)
C-Nuclear Morphology
1-Nuclear size: small,medium,large2-Number per cell: one nuclus,two nuclei
(liver cells,superficial cells of transitional epithelium)&many nuclei (osteoclast cells of bone&skeletal muscle cells
3-shape : round,oval,flattened,rod-shaped,kidney shape,segmented
Nuclear location:basal,central or eccentric
![Page 4: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/4.jpg)
Nuclear Structures
![Page 5: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/5.jpg)
Structures of nucleus
Four components1-nuclear envelope
2-nuclear sap3-nucleolus
4-Nuclear chromatin
![Page 6: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/6.jpg)
1-Nuclear envelope
Dark basophilic membrane which surrounds the nucleus
LM: appears as single dark membranea-Inner fibrillar membrane(rich in chromatin
fibersb-outer granular membrane(rich in ribosomes)
c-nuclear pores(formed nuclear membrane complex which is formed of peripheral spoks&cenral plug this plug diaphragm which regulate the passage of protein from cytoplasm to enter the nucleus
![Page 7: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/7.jpg)
High mag TEM of a nucleolus
Pars fibrosa/granulosa (dense black) and
fibrillar center (arrow)
![Page 8: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/8.jpg)
2-Nuclear Sap
It is acolloidal clear solution,it is formed of
nucleoproteins,enzymes,phosphors,potassium&calciumTwo type of nuclei
1 -open face nucleus: large amount of nuclear sap present in liver cells
2 -condensed nucleus: less amount of nuclear sap(lymphocyte)
Function of nuclear sap1 -provide amedium in which ribonucleic acid(Ri,t&m
RNA)2-Move towards the nuclear pores
![Page 9: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/9.jpg)
3-nucleolus:
basophilic mass formed of RNA&DNA
The nucleolus may enlarge in size in protein forming cells in rapidly growing cancer cells
LM: dark basophilic massFunction of the nucleolus
It forms rRNA&mRNA
![Page 10: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/10.jpg)
4-Chromatin material
basophilic particles&chromosomes are formed during cell division
Structures: are formed mainly of nucleoprotein which is formed of DNA nound to basic protein called histones
Stain:basophilic due to presence of DNA
LM: basophilic granules
![Page 11: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/11.jpg)
There are two type of chromatin
1-Euchromatin(active chromatin2-Heterochromatin(In active)
![Page 12: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/12.jpg)
1-Euchromatin:
Invisible by LMVery lightly with basic stain
Most active chromatinControl protein synthesis
![Page 13: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/13.jpg)
2-Heterochromatin:
inactive chromatinVisible by LM as cours granules
Appears as masses of nucleoprotein called nucleosomes
Stain dark with basic stainThey do not dirct any protein
synthesis
![Page 14: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/14.jpg)
Function of chromatin
1-guides protein synthesis inside the cell
2-stores the genetic information of the individuals
3-DNA chromatin material====rRNA,mRNA,tRNA are formed
![Page 15: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/15.jpg)
TEM of interphase nuclei and a mitotic cell with condensed chromosomes (arrow)
![Page 16: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/16.jpg)
Nuclear pores (arrows) Nuclear pores (en face)
![Page 17: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/17.jpg)
Colorized TEM of nuclear pores (blue) en face
![Page 18: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/18.jpg)
![Page 19: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/19.jpg)
Nucleic Acid
They are the bases of life,control the cellular functions
Two Types of nucleic acid: DNA&RNA
![Page 20: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/20.jpg)
1-DNA= Deoxy-ribonucleic acid
DNA molecules are present in the nuclear chromatin,chromosomes&mitochondria
DNA represent the hereditary substances or genes
DNA molecules consists of two chins forming double helix
There are 4 types of nitrogenous bases in DNA molecules
![Page 21: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/21.jpg)
1-Adenine(A) ,2-Thymine (T),3-Guanine(G),4-cystosine (C)
DNA carries&stores the genetic,information of ech cell
DNA transfers the genetic information by the following 2 processes
a-replication of DNA to to form more DNAb-transcription of DNA to form 3 types of
RNA
![Page 22: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/22.jpg)
2-RNA= Ribonucleic Acid
The same structure to DNA but with some differences
DNA: present in nucleus,mitochondria of cytoplasm
DNA present in the nucleus&cytoplasmDNA: takes blue colour=========
RNA: takes red colour=========Methyl-green-pyronin stain
![Page 23: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/23.jpg)
1-Ribosomal RNA=r-RNA
They are formed in the nucleolus from loops of DNA
Move to the cytoplasma&are known as ribosomes
Present free in cytoplasmFunction: they are the sites for protein
synthesis
![Page 24: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/24.jpg)
2-Messenger RNA=mRNA
Information codes for proteine synthesis are present on DNA
DNA---------------mRNA======which control the processes of protein synthesis
mRNA can direct the synthesis of many identical protein signal which indicate where to begin and where to end translation
![Page 25: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/25.jpg)
3-Transfer RNA=tRNA
t-RNA are formed inside the nucleus from DNA has two arms
a-tRNa==attched to amino acid== called anticodon
![Page 26: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/26.jpg)
DNA is used to produce mRNATranscription
![Page 27: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/27.jpg)
Steps of protein Synthesis in the cell
1-DNA molecule: specific types of protein which share information of hormones&enzymes
2-DNA: have ability to from copies of DNA by replication of DNA
3-DNA :can manufacture three kinds of RNA
![Page 28: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/28.jpg)
a-r-RNA=protein factoriesb-m-RNA=code carries
c-t-RNA=Amino acid transfers
![Page 29: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/29.jpg)
4-m-RNA molecule in the cytoplasm&association with
a-ribosomes(read the secret messages which are present on the mRNA
b-three t-RNA molecules(wanted amino acids from the cytoplasm
c-three amino acids
![Page 30: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/30.jpg)
5-amino acid by tRNA====mRNA&correct aligment
6-amino acids to form apolypeptide7-release polypeptide&dissociation
of ribosomes from messenger RNA====newly synthesized protein
![Page 31: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/31.jpg)
Ribosomes
-composed of rRNA (ribosomal RNA) & protein -may be dispersed randomly throughout the cytoplasm or attached to surface of rough endoplasmic reticulum -often linked together in chains called polyribosomes or polysomes -Primary function to produce proteins
![Page 32: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/32.jpg)
Protein synthesisThe principal organelles involved are The nucleus
+ ribosomesTranscription mRNA molecule cytoplasm
associate
Ribosomal RNA+ associated proteins globular structure
Transfer RNARibosomes +mRNA molecules polyribosomes or polysomes attached to intracytoplasmic
membrane system known as ENDOPLASMIC RETICULUM
+
![Page 33: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/33.jpg)
![Page 34: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/34.jpg)
TRANSLATION mRNA then moves from the nucleus into the
cytoplasm & is used to produce a protein
![Page 35: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/35.jpg)
The life cycle of the cell
Changes which occur in the cell during division(mitosis)&during rest(Interphase)
The cell cycle==mitotic part(two doughter cell)
== Interphase part (resting condition before starting another cell division
![Page 36: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/36.jpg)
Subdivide into 3 three stages
1-G-1 stage(Gap one stage)presynthesis): 46-s-Chromosomes
2-S.2 stage(DNA synthesis)replication of DNA molecules have 46 identical paris of chromatids(92 chromatids
3-G2(post DNA duplication): have 46 D-chromosomes
![Page 37: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/37.jpg)
Types of cells in relation to their cell renewal
Three types of cells in the body1-Non-renewing cells
Cells cannt divide== nerve cells they are not replaced
2-continously renewing cellsThese cells unable to divide:replaced by
doughter cells arising from mother cells called stem cells of the same family
![Page 38: Nucleus General features of nuclei A-Major components 1-nuclear envelope 2-Nuclear Sap 3-one to several nucleoli 4-Nuclear chromatins.](https://reader036.fdocuments.us/reader036/viewer/2022062421/56649e675503460f94b62693/html5/thumbnails/38.jpg)
Stem cells
a-unipotential stem cell: one type of the cells ex. Testicular cells
b-multipotential stem cells: bone marrow cells produce different type of cells
3-potential-renewble cellsEx.of these cells are:liver cells&endocrine cells
Nuclear changes during cell necrosis
1-pyknosis:nucleus becomes smaller&deeply stained
2-karyorrhexis:nucleus breks into small fragmentsKaryolisis:the nucleus dissolves&disappears