Nucleic acids Notes

genes individual segments of chromosome that codes for the production of
a a
Polypeptide
determines characteristics of individual cells (a. a chain)



NB :
functions of Nucleus

1
Genes contain info proteins Inc enzymes that control cell activities
necessary to make .
.




2 Provides info to
cytoplasm } Organelles to keep fell
functioning




Chromatin Levels
Density > not being read


•
Dark -



staining chromatin :
tightly packed ☐µ,
read to produce proteins
no DNA that is
being actively
•
Lighter staining chromatin
-
:
loosely packed DNA




2 major components of chromatin



① DNA : DEOXY Ribonucleic Acid
whose structure is coded the info of inheritance } the info for
molecule of hereditary within controlling
the cell



proteins (AKA histones) • Stabilize DNA molecules




3 1 01 more nucleoli found in nucleus

• dark -


staining spherical structures
•
synthesise ribosomes
by producing ribosomal RNA } Package it w/ ribosomal proteins to make

ribosomes




4 Nucleoplasm •
Contains ions } molecules
necessary for construction of nucleic acids
( manufactured in nucleus )

, (CHR0MOSOMES~@ chromatid
,BBeqg⑨BBg 1
Centromia

Chromatin network
•
DNA molecule unraveled =
4.8cm
total DNA length in nucleus 2.2m
•
=




•
DNA =

intricately folded { tightly bound around Histones



Nuclear membrane

cell membrane
""
Nucleolus network




Goa k
÷
Nucleoplasm



Nucleus cytoplasm 11 substances move in
Nuclear pore and out
Diagram A
Diagram B.

nuclear pore control exchange of
• -




materials between nucleus } Cytoplasm


•
nucleus contains chromatin network Chas DNA)


•

enclosed by nuclear envelope




analysis of the chromatin network reveals that it is made of two major
components