NUCLEUS Flashcards
the largest organelle , It is usually spheroid to elliptical in shape , and typically about 5 μ in diameter .
the nucleus
Most cells have a single nucleus, but there are exceptions
a nuclear / multinuclear
no nucleus
a nuclear
several nucleus
multinuclear
It contains the chromosomes inside it and is responsible for the transmission of genetic traits and controls cell division and cellular functions and activities , Inside the nucleus is a small body known as the nucleus , The nucleus is surrounded by a membrane with small nuclear holes that act as a means of transport and exchange from the nucleus between the cytoplasm .
the nucleus
Nuclear envelope , Nucleolus , Nucleoplasm
, Chromosomes
contents of the nucleus
It consists of two layers of membranes surrounding the contents of the cell , It has holes that allow specific molecules to pass outside the nucleus .
nuclear envelope
It is a dark and dense region that forms RNA
A place to manufacture (ribosomal RNA (rRNA)).
It fades upon cell division
nucleus
It is the substance or liquid inside the nucleus
nucleoplasm
They are convoluted bodies which are condensed chromatin , It contains the genetic material that is transferred from parents to children during reproduction
chromosomes
DNA , Gene or allele , Chromatin , Chromosome
they are the genetic materials
consist of a nucleotide replicate
nucleic acids
ribose sugar , nitrogenous bases , phosphate group
contents of the nucleotide
When nucleotide is bound together in chains it is known as
polynucleotide
Ribose sugar plus nitrogen base equal to
nucleoside
A nitrogenous base consisting of two rings
purines
A single-ring nitrogen base
Pyrimidines
deoxy ribonucleic acids
DNA
ribonucleic acids
RNA
in nucleus can leave
DNA
leave the nucleus , its function at cytoplasm
RNA
have two double helix nucleotide chains
DNA
one nucleotide chains
RNA
A.T.C.G. nitrogenous bases
DNA
A.U.C.G. nitrogenous bases
RNA
Deoxyribose sugar
DNA
Ribose sugar
RNA
Codes for synthesis of RNA and proteins
function of DNA
Carries out instructions in DNA, assembles proteins
function of RNA
one type only
DNA
have three types
RNA
mRNA , tRNA , rRNA
types of RNA
Polynucleotide strands are found in the nucleus and mitochondria, which have a Thymine base
DNA
have a complementary and antiparallel
DNA
Nitrogenous bases are bound together by hydrogen bonds , which links nucleotide are phosphatic links
complementary of DNA
Means that each thread is in the opposite direction
antiparallel
Is the bond between the phosphate of one nucleotide 5’ and the hydroxyl group of the next nucleotide 3’
Phosphodiester Bond
It is a single strand of polynucleotide found in the nucleus and cytoplasm having a base of Uracil instead of Thymine.
RNA
Transferring the genetic code, storing the genetic information and passing it on from one generation to another, and gives the code to be translated into a protein in the cell by mRNA.
DNA function
Storage and transmission of genetic information , Stimulus , The rRNA syntax , Protein synthesis .
the function of the RNA
It carries messages in ‘codon’ form . to manufacture protein
m RNA
AUG
its the start codon
UAA,UAG, UGA
they are the terminal codon
3 nucleotides
codon , anticodon
Holds the code ‘anticodon’
t RNA
part of the ribosome structure and it has a role in protein synthesis
r RNA
It is the genetic material during cell division and DNA folds and condenses in the form of a chromosome, and the length of one DNA molecule reaches about 2 meters and the diameter of the nucleus does not exceed 10 microns, so it takes a space inside the nucleus and wraps more than 16 thousand times (super coiled) .
chromosome structure and nature
Each chromosome has a region associated with the spindle, at the centromere cell division
Each chromosome consists of 2 chromatids when dividing two lengths in the Centromere region
Each Chromatid has two Telomere arms
The first is short over the Centromere called p arm
The other is long below the Centromere called q arm
chromosome structure and nature
Acrocentric ‘Terminal’ , Submetacentric ‘Near medial’ , Metacentric ‘medial’ , Telocentric ‘final’ .
terms according to length and position of centromeres
similar pairs of chromosomes
homologues chromosomes
there is two types of chromosomes
sex chromosomes , autosomal chromosomes
XX sexual chromosomes
females sexual chromosomes
XY sexual chromosomes
males sexual chromosomes
Shape and number of chromosomes in eukaryotic cells are different depending on the type
karyotype
It is the genetic material outside the cell division, that is, in the interphase, which is a complex structure of protein and DNA that is not coiled without condensation
chromatin
euchromatin and heterochromatin
they are types of chromatin
the active part (copies and synthesizes protein)
euchromatin
the inactive part is usually dense ( neither used nor copied, found in (Telomere - Centromere) area . )
heterochromatin
The DNA strand binds to both histone and non-histone proteins , Nucleosome = DNA + Histone proteins , Histone proteins work by tightly regulating and wrapping DNA and converting it from chromatin filaments to chromosomes inside the nucleus of real cells , Non-histone proteins regulate gene activity and support their synthesis
DNA binding to proteins
Nucleosome = DNA + Histone proteins , Histone proteins act on bundles of eukaryotic genetic material and are in the form of Histone octamer. These octets consist of H3, H4, H2B, H2A except for H1
Nucleosome
DNA is the complete combination of
genome
it is part of the DNA in the chromosome In eukaryotes
It has a special place on the chromosome
The place assigned to it is called locus
Each gene has its own code, which is a special sequence of amino acids that is transcribed by rRNA, tRNA, and mRNA.
gene
