Tutor profile: Alejandro D.
Subject: R Programming
What are the differences between "<-" and "="
Nothing! They are both assignment operators and they can be used to assign something to a variable. They can also be used in the opposite direction ("->")
Subject: Basic Chemistry
What is an acid?
An acid is a substance that has a pH concentration of less than 7. pH is a way of measuring the number of Hydrogen ions in a solution. This can be measured with the equation -log[H+] If the pH is 7, that means that the number of Hydrogen ions is equal to the number of hydroxide ions.
What are the steps of DNA replication?
The first step of DNA replication is to unwind the two DNA strands. This is done with the help of and helicase which breaks apart the hydrogen bonds and creates a replication fork. The replication fork is composed of a leading strand (3' -> 5' direction) and the lagging strand (5' -> 3' direction). For the leading strand, RNA primers are able to bind to their complementary bases. The DNA polymerase will bind to the leading strand and add complementary bases. Since DNA polymerase can only work in the 5' -> 3' direction, the lagging strand is replicated discontinuously. In other words, the complementary strand will be built in fragments called Okazaki fragments. Afterward, an exonuclease will remove the RNA primers while another exonuclease error corrects the newly synthesized strand. Ligase will "glue" the different Okazaki fragments together. The DNA will then coil back to its helical shape.
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