المحاضرة الرابعة من الجين

lecture4
DNA repair:

-if there's mispair (one or more than one nucleotide(either base ,or the whole nucleotide), and this happened each day in one cell about a million mismatch escape the proofreading property of DNA polymerase.
_agents which cause mutations or alteration could be
endogenous(mainly by replication system mispair)
exogenous(by radiation,chemicals,UV light,free radicals....etc)
_ newly synthesized strands aren't methylated,so this is use to identify ,and diffrentiate b\w them and parental strand(v.imp).
-excinuclease v.imp identify and excise the dimers by UV specific endonuclease.
-xeroderma pigmentosum v.imp
_correction of base alteration :
cytosine is deaminated to uracil by nitrous oxide,there will removal of base(uracil)by uracil N glycosylase(can recognize ) and Apyrimidinic site is formed,then apyrimidinic endonuclease will cut the strand ,so the lyase will cut in order for DNA poly can work and ligase will seal both parts of the strand.
_repair of ds. breaks :
those breaks caused by radiation and free radicals or gene rearragements.
-house keeping genes breaks is lethal
-high eupkaryotes(plants and animals)
-lower euokaryotes(monocellualar ,fungi ,viruces,algae)
-there's no repair in transcription
RNA is single strand of ribonucleac acid
functions of different RNA are imp
DNA mutation is replicated b\c genetic material of DNA is preserved as it is.
and,this will result may may be in producing supraactive enzyme or non functioning one.
in 5 prime of mRNA there's a cap(protect from exonucleases)and it's consists of methyl guanosine triposhpate,and recognition
in 3 prime ther's poly A tail also protect from exonuclease actitvity.
rRNA is part of ribosomes(rRNA+proteins)
tRNA transfer of A.As and contain anticodon that recognize the seqense of nucleotide in order to put the right A.As on

ملف بايو2 كامل

lecture 5
mRNA production occur in nucleus,but it's function in ribosomes and it's giuded by special eupkaryotic str. that exist in the 5 prime end a chemical str. called cap and it exist for two purposes:
(protection\recognetion).
Genome : all DNA that is present in organism
the number of nucleotides(bp): it's not proportional to number of genes ,it doesn't mean that the more chr. the more the number of genes .
there's no different in gens b\w human (healthy individuals)
-gene expression=transcription+translation(in case of protein only)
because for example tRNA ,rRNA,and snRNA are only transcribed.
-RNA polymerase synthesize the RNA strand in direction of 5prime to 3 prime
-promotor is never transcribed(receive receptor hormone complex ,and regulate the process)
-the genes and promoters are the same in each cell for the same gene ,but what make the promoter start a transcription of same genes differntly is the transcription factors and acticvators
-holoenzyme:is very imp. recognize promoter region.
-difference b\w replication &transcription is very imp.

المحاضرة الخامسة من الجين ركزوا ع الرسمات!

تعديل
صفحة 6
DNA poly. I read the lagging strand from 3to 5 prime direction and synthesize it from 5 to 3.

لاستقبال أسئلتكم واستفساراتكم وأيضًا اقتراحاتكم👆🏻

زملاؤنا المتقدمين لامتحان BC142، هذه بعض الحاجات اللي ممكن تفيدكم:

تفريغـات لمحاضرات دكتور عبّاس، يُعتبر د.عبّاس عقبري البايوكيمستري في مصر، ويوصل في المعلومة بطريقة سلسة ولا تُنسى، وأنا شخصيًّا استفدت منّه في شابتر الأمينو ميتابوليزم، وكانت الأسئلة ساهلة -في نظري- بالرغم من صعوبتها.

Lipid metabolism:
https://drive.google.com/drive/mobile/folders/0B1CphvNl8KscaEEwMmNUOWtfbUE?usp=drive_web&tid=0B1CphvNl8KscaGpaOG5qZWtfbFk

Amino acid metabolism:

https://drive.google.com/drive/mobile/folders/0B1CphvNl8KscWGNLRkJpMUxIeUk?usp=drive_web&tid=0B1CphvNl8KscaGpaOG5qZWtfbFk

Playlist لمنهج بايو 2+3
د.عبّـاس.
https://www.youtube.com/playlist?list=PL0_tN0panMs-Iz5zKo_ObzfjAYgAWrchI

https://www.mediafire.com/folder/v3u476n862i79
ملف بايو 2 كامل.
يتضمن شيتات وتسجيلات د.محمد القرقوري.

شيت د.عبّــاس:
Lipid metabolism :
http://www.mediafire.com/file/k9j957dlu37n929/

كتاب عُرابي المنهج النظري:

http://www.mediafire.com/file/g775s70spaa6w6s/

كتاب عُرابي MCQs:

http://www.mediafire.com/file/3u8vxqr5hnaq3w6/Biochemistry+Questions+%26+Answers+Said+Oraby+..+Volume+II+..+Abdulrahman+Zaghloul.pdf

وهذا ما لدينا حتّى الآن لِ BC142، موفّقين، سهّل الله أمركم.

#SoMA
#BC142

Mnemonics for memorizing classification of A.As

Mnemonics تسهل تصنيف amino acids تعبر مراجعة

https://www.youtube.com/playlist?list=PLTF9h-T1TcJhy6Og8piwo8doDJavTFOvg

نينجا نيرد!!
ما تفوتوشي في الـ metabolism!