#DNA replication

[robotics5]

You've heard of angels as machinery, but what about angels as molecular machinery? Proteins and the like. Imagine a topoisomerase angel unwinding the threads of fate, which are then split apart into multiple timelines by a helicase angel

[barelyacademia]

basics of dna replication

[justkidneying]

The Origin of Your Genetic Material

You may not have even an itch in your dad's pants a few decades ago, but you were an egg in your mom's ovary.

What I'm trying to say is that females are born with all the (precursors to) eggs they will ever have (about 400 of them), while males continue to produce gametes throughout their life. I'm talking about MEIOSIS!

Meiosis makes four cells (each with half the original DNA) and is involved with sexual reproduction. Mitosis makes two identical cells and is necessary for life.

Now, let's go back to when you were an embryo. A group of cells (primordial germ cells) was set aside. Eventually, they go to your gonads. If this gonad becomes an ovary, they will become ova (eggs). If the gonad becomes a testis, they will become spermatozoa. This doesn't actually happen until puberty. Before that wonderful event, they're still primordial germ cells.

The cool thing is that the primordial germ cells in a female embryo are all that she will ever have. Meiosis of these cells begins while you are in the womb, but stops in the first Meiosis (there are two cycles of meiosis).

For every cell that goes through Meiosis I & II, there are four things produced. For male sex cells, there are four sperm made. For females, there is one egg and three polar bodies.

For males, this happens billions of times in an hour. For females, this happens once a month, one at a time. The 400 germ cells give enough eggs to menstrate from about 13 to 40 years old. Then menopause happens because she ran out of germ cells to make ova from.

Fertilization happens when a sperm meets an ova, and there is finally a complete set of DNA (46 chromosomes). This is made of 22 pairs of regular DNA, and 1 pair of sex chromosomes. The sex of the embryo is determined by the sperm.

A lot of fun diseases are X-linked. I could name some, but that would be a waste of time. The cooler thing is that mitochondrial (the power house of the cell) DNA only comes from your mother. It's also round (unlike the regular helix) and mitochondria act more like bacteria when they replicate (binary fission). So mitochondrial disorders all have a maternal inheritance pattern.

[er-cryptid]

Major Eukaryotic DNA Polymerases

Patreon

[kamalkafir-blog]

Multigenerational cell tracking of DNA replication and heritable DNA damage

Cell culture and treatments All cell lines were grown at 37 °C under standard cell culture conditions (humidified atmosphere, 5% CO2) in Dulbecco’s modified Eagle’s medium (DMEM, Gibco) containing 10% FBS (Corning) and 1% penicillin–streptomycin antibiotics. Stable endogenously tagged U-2 OS PCNA–mEmerald 53BP1–mScarlet cells were maintained in the presence of 4 µg ml−1 blasticidin (InvivoGen)…

[ruxxspinstalkedhome]

Your an evil person and your spending this countries money on online slots. Real founders don't need to be pedophiles to stay who they were born as. You've taken our blood and harvested everything so you could transfer it to people who heist bees and hide in the mountains likely with stolen children. Yoive hacked my families network so you can use it as a tivo to breed more weirdos. I'm framing Skylar roski for being in Jesus Christs apps. Fucking help. They just use us to create spinoff versions. He never deserved this.

Shame. on. you!

[biology-geology-beaches-india]

TSRNOSS, page 206.

[bestupsciascoachingdelhi]

Mechanism of DNA Replication: A Key Concept for Zoology Optional in UPSC By Pradip Sarkar | Sapiens IAS

DNA replication is one of the most crucial biological processes, fundamental to life, as it ensures the transmission of genetic information from one generation to the next. For aspirants of the UPSC Civil Services Exam, particularly those opting for Zoology as their optional subject, understanding the intricacies of DNA replication is essential. Under the expert guidance of Pradip Sarkar at Sapiens IAS, students delve into this topic, gaining insights not only for the exam but for their broader understanding of biological sciences.

What is DNA Replication?

DNA replication refers to the process by which a cell copies its DNA, creating two identical sets of DNA. This process occurs during the S-phase of the cell cycle and is vital for cell division, whether through mitosis or meiosis. Each resulting daughter cell receives an identical copy of DNA, ensuring continuity of genetic information.

DNA replication follows a semi-conservative model, meaning that each of the two new DNA molecules consists of one original (parent) strand and one newly synthesized strand. This model was confirmed by the famous Meselson-Stahl experiment and remains a core concept in genetics.

Why is DNA Replication Important?

The accurate replication of DNA ensures the faithful transmission of genetic information from parent to offspring. Any errors during replication can lead to mutations, which may result in genetic disorders, diseases, or evolutionary changes. This makes DNA replication not only a biological necessity but also a key area of study in fields like evolutionary biology, genetics, and medicine.

Mechanism of DNA Replication

DNA replication is a highly coordinated process involving multiple enzymes and steps. Here’s a step-by-step overview of the mechanism:

1. Initiation

Replication begins at specific sites called origins of replication. In prokaryotes, there is typically one origin, while eukaryotes have multiple origins due to their larger genome. At the origin, DNA helicase unwinds the double helix, creating a replication fork, where the DNA strands are separated and made available for replication.

2. Unwinding of DNA

The enzyme helicase breaks the hydrogen bonds between the base pairs of the DNA strands, unwinding the helix. Single-strand binding proteins (SSBs) then stabilize the separated strands, preventing them from reannealing.

3. Primer Synthesis

DNA polymerase, the enzyme responsible for synthesizing new DNA strands, cannot initiate synthesis on its own. It requires a short RNA primer. The enzyme primase synthesizes these RNA primers, which provide the starting point for DNA polymerase to begin adding nucleotides.

4. Elongation

DNA polymerase III, the key enzyme in replication, adds nucleotides to the growing DNA strand in a 5' to 3' direction. The process differs slightly for the two strands:

Leading Strand: DNA polymerase continuously synthesizes the leading strand, moving toward the replication fork in a 5' to 3' direction.

Lagging Strand: The lagging strand is synthesized discontinuously, in short fragments called Okazaki fragments. DNA polymerase works in the opposite direction of the replication fork, so the synthesis of the lagging strand happens in short bursts.

5. Joining of Fragments

Once the lagging strand has been synthesized, the Okazaki fragments need to be joined together to form a continuous strand. This is accomplished by the enzyme DNA ligase, which seals the gaps between the fragments.

6. Termination

Replication continues until the entire DNA molecule has been copied. In prokaryotes, this usually happens when two replication forks meet. In eukaryotes, termination occurs at specific sequences known as telomeres at the ends of chromosomes. Special enzymes called telomerases help extend the ends of chromosomes, preventing their shortening during replication.

Significance of DNA Replication in Zoology Optional for UPSC

For UPSC aspirants, especially those who have chosen Zoology as their optional subject, understanding DNA replication is vital. This topic is not only essential for conceptual clarity in molecular biology but also connects with other topics like genetics, cell biology, and evolutionary biology. The depth of understanding required for the UPSC exam, particularly for the Mains paper, is significant. Students need to explain these processes clearly, sometimes even diagrammatically.

At Sapiens IAS, under the mentorship of Pradip Sarkar, students are provided with detailed explanations, diagrams, and real-life examples to grasp the complex mechanisms of DNA replication. His teaching methodology simplifies tough concepts, making it easier for aspirants to comprehend and retain knowledge.

Conclusion

DNA replication is a fundamental biological process that ensures genetic continuity across generations. For UPSC aspirants with Zoology as their optional, mastering this concept is essential for success in the exam. With expert guidance from Pradip Sarkar at Sapiens IAS, students can develop a deep understanding of the mechanisms involved, preparing them to tackle both theoretical and applied questions in the exam.

[one-shitpost-a-day]

til that dna polymerase is shaped like a right hand??? with like fingers and a thumb and a palm

just thought that was interesting

[tenth-sentence]

It is a dimeric protein that binds with exceptionally high affinity to duplex DNA at specific nucleotide sequences forming a termination complex that prevents further DNA replication.

"Chemistry" 2e - Blackman, A., Bottle, S., Schmid, S., Mocerino, M., Wille, U.

[scichores]

What is Chromosome remodeling? Explained

Imagine a library with millions of books tightly bound together – that's kind of like DNA in chromosomes without remodeling. Remodeling acts like librarians carefully unstacking and organizing books to make them accessible to readers. Read more...

CHROMOSOME REMODELING Chromosome remodeling is a vital process within cells that ensures the DNA instructions encoded in chromosomes can be accessed and used when needed. Imagine a library with millions of books tightly bound together – that’s kind of like DNA in chromosomes without remodeling. Remodeling acts like librarians carefully unstacking and organizing books to make them accessible to…

[christianityandculture]

Origin of Life: You Can't Trust Everything You Hear (Long Story Short, E...

[clinquant-afternoon]

9/20/23

DNA replication is the single most complicated process I have ever encountered but I’m happy that it makes flowers possible.

[ouransisters]

"There was a fight to determine the heir and Danny lost" "Danny faked his death on a mission and ran away" "it wasn't safe and Talia smuggled Danny away" NO. Danny tripped and fell into the lazarus pit! The evil green goo dumped him in the American midwest and now he's being raised by these random mad scientists!

[the-worms-in-your-bones]

‘The timeless child means that river would have to be Amy and the doctors daughter’

Hey, hey come here, I have something to tell you. Ignore the hammer

[k20spock]

if i have to see one more article going omg dire wolves have been brought back from extinction!! im gonna strangle somebody