나는 Yr13 Biology를 공부하는 학생들에게 Okazaki fragment가 시험에 나오든 안나오든 무조건 이해하고 설명하는 방법을 익히기를 심하게(?) 권유한다. 이유는 역시 경험해본바, 이해하지 않고는 한해한해 고달플수 있기때문이다. Health Science, Biomedicine, Pharmacy, Chiropractic등 생물과목을 듣는 학과에 입학하게 되면 1학년 부터 세포학과목과 Genetic과목을 들을텐데 DNA Replication을 제대로 이해하지 못하면 과목 한번 통과하기가 산넘어 산이다..어쩌면 에베레스트 등반만큼 어려운 길이 될수도 있다.
어쩌면 내 두뇌가 그다지 명석하지 못해서 그랬을수도 있다. 어쨌거나 배워두면 이래저래 WIN WIN 게임인데, 이왕 배우는거 기쁜맘으로(!!) 제대로 배우고 가는게 좋지 않을까? 
The overall unzipping process is in one direction, from the bottom of the diagram up to the top. However, there are 2 chains. As the new DNA chains only grow in the 5′ to 3′ direction they must grow in opposite directions.
The 2 strands of the original DNA molecule run in opposite directions.
* 이부분에서 헷갈리는건 5’과 3’의 존재다. Carbon number를 세어보도록 하자.
The deoxyribose sugar is a 5carbon sugar. Each of the carbon atoms in the sugar is given a number. These 5 carbon sugars are connected by phosphates and the end that finishes with carbon 5 exposed is the 5’end, the other is the 3′ end. In reality each sugar has a base attached so we have a chain of nucleotides. A complete DNA molecule is a double helix with the two strands running in opposite directions.
The incoming nucleotide units can join only to the exposed 3′ end thus a new DNA chain can grow only in the 5′ to 3′ direction. The strand that has its 5’end exposed is called the leading strand and grows continuously, towards the replication fork. The other strand (lagging strand) cannot start from the exposed 3′ end so instead it starts growing from a carbon 5 at the fork. It then grows away from the fork toward the 3′ end. As the fork unravels, exposing more bases, another Okazaki fragment starts forming at the fork and grows toward where the previous Okazaki fragment started from. When they meet they join up to eventually form a single lagging strand.
ref: University Busary Biology;1996;Terry Bunn and Max Thompson