The process of DNA duplication is usually called Replication.
The replication is termed “Semiconservative” since each new cell contains one strand of original DNA and one newly synthesized strand of DNA. The original polynucleotide strand of DNA serves as a template to guide the synthesis of the new complementary polynucleotide of DNA.
In a cell, DNA replication begins at specific locations in the genome, called "origins of replication.”
STEPS OF DNA REPLICATION
TELOMERES
- Repetitive sequences at the ends of the linear DNA molecule in eukaryotic chromosomes.
- With each round of replication, these are shortened because DNA polymerase can’t complete synthesis of 5’ end of the each strand.
- This contributes to aging of the cells.
TELOMERASE
- An enzyme in eukaryotes used to maintain the telomeres.
- Has telomerase reverse transcriptase activity.
- Present only in embryonic cells, germ cells (reproductive) and stem cells.
SIGNIFICANCE OF TELOMERASE
Cancer cells have high levels of telomerase which prevents telomeres from being short and contribute to immortality of malignant cells.
REVERSE TRANSCRIPTASE
RNA dependant DNA polymerase
Requires RNA template to direct the synthesis of new DNA.
Retroviruses (HIV) have this activity.
COMPARISION OF DNA & RNA SYNTHESIS
DNA REPAIR
Can be damaged by chemicals or radiation
Incorrect bases can also be incorporated during replication.
Multiple repair systems have evolved, allowing cells to maintain the sequence stability of their genomes.
1. Excision Endonuclease
2. Uracil glycosylase
3. AP endonuclease
REPAIR OF THYMINE DIMER
REPAIR OF DEAMINATED & MISSING BASES
Cytosine can become deaminated spontaneously by reaction with nitrous acid to form Uracil
+(third+to+fourth)+and+(at+time+of+birth)of+pregnancy.png)
mbbs in Philippines
ReplyDeleteEvery year, almost 8000 foreign students take admission in Philippines Medical universities and out of which around 50% are Indian students. The standard of education in Philippines universities is well known around the world. Thousands of doctors from these medical universities are sent to various countries like USA and UK every year. There are around 2299 higher educational institutions and 40 medical colleges. The main benefits of pursuing MD degree from
Top Medical Colleges in Philippines :
EMILIO AGUINALDO COLLEGE OF MEDICINE
UNIVERSITY OF PERPETUAL HELP SYSTEM DALTA
LYCEUM NORTHWESTERN UNIVERSITY
DAVAO MEDICAL SCHOOL FOUNDATION
SOUTHWESTERN UNIVERSITY
Top Searched Topics on MBBS in Philippines
study mbbs in philippines
philippines medical colleges list
best medical colleges in philippines for indian students
philippines medical colleges
best medical colleges in philippines
mci approved medical colleges in philippines
for more information contact us : +91 90329 55688
Great post I would like to thank you for the efforts you have made in writing this interesting and knowledgeable article. https://www.xetnghiemadnchacon.com/dich-vu/
ReplyDeleteUV GULLAS COLLEGE OF MEDICINE is one of Top Medical College in Philippines in Cebu city. International students have the oppertunity to study medicine in phillipines at affordable cost and world class University. The college has successful alumni who have achieved well in the fields of law, business, politics, academe, medicine, sports and other endeavors. At University of the Visayas, we prepare students for a global competition.
ReplyDeleteDirect MBBS Admissions Open: 2020-21
Mobile No: +91 90329 55688
Apply Now: https://www.careerplus.org.in/philippines-medical-college/uv-gullas-college-of-medicine
New potential in the cellular Zero Rate Merchant Accounts is a natural result of the rapid advances in mobile wireless technologies. Now is the time to learn about and train in cellular repair to reap the rewards of a vocation that is fast becoming a mainstay in today's world.
ReplyDeleteLCD TVs can really save you from high electricity bills and office space~ Mega888 android and ios
ReplyDeleteWohh just what I was searching for, appreciate it for putting up. best wireless earbuds 2021
ReplyDelete