Biology HL
Biology HL
4
Chapters
553
Notes
Theme A - Unity & diversity
Theme A - Unity & diversity
Theme B - Form & Function
Theme B - Form & Function
Theme C - Interaction &  Interdependence
Theme C - Interaction & Interdependence
Theme D - Continuity & Change
Theme D - Continuity & Change
IB Resources
Theme D - Continuity & Change
Biology HL
Biology HL

Theme D - Continuity & Change

Revolutionize Gene Editing Unlock CRISPR-Cas9 Secrets

Word Count Emoji
570 words
Reading Time Emoji
3 mins read
Updated at Emoji
Last edited on 14th Jun 2024

Table of content

In a Nutshell 🌟

The CRISPR-Cas9 system, borrowed from prokaryotes, is like the "find and replace" function in a word processor, but for genes! Let's break it down.

CRISPR Basics

C.R.I.S.P.R: Like the crisps you munch on? Not really! It stands for Clustered Regularly Interspaced Short Palindromic Repeats. Here's what each word means

  • Repeats: Same base sequence pops up multiple times.
  • Short: Just between 23 and 47 base pairs. Tiny, right?
  • Clustered: All grouped together like a reunion.
  • Regularly Interspersed: Between these repeats are unique sequences called spacers. Think of them as dividers in a cookie box.
  • Fun fact: these spacers come from viruses that tried to attack the prokaryotes. It's like a genetic "Most Wanted" poster!
  • Palindromic: Reads similarly backward and forward (almost).

The Role of Cas9

  • It's a natural enzyme, acting like a DNA detective.
  • Its partner-in-crime is guide RNA (gRNA) that's derived from a CRISPR array.
  • As it moves along DNA, it seeks out specific sequences to match with its gRNA.
  • Once it finds a match, it performs a snip-snip action, cutting through the DNA.

💡 Real-world example: Imagine a barcode scanner scanning products to find a match. Cas9 is the scanner, and the gRNA is the barcode it's looking for.

How Do We Use It for Gene Editing?

  • Scientists always wanted a tool like search and replace for genes. Enter CRISPR-Cas9!
  • Prime editing: An improved method using special RNA, pegRNA. It's kind of like CRISPR 2.0.
    • This RNA connects with modified Cas9, looking for target genes.
    • When found, instead of a double-cut, it makes a single cut (nick) in the DNA.
    • Using a feature of pegRNA, new genetic information is added, replacing the old.
    • Our body's natural repair system takes over from here, fixing any mismatches.

💡 Real-world example: It's like using an advanced software patch to fix bugs in a program. The software (CRISPR) searches for the bug (specific gene sequence), then patches it (modifies it)!

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IB Resources
Theme D - Continuity & Change
Biology HL
Biology HL

Theme D - Continuity & Change

Revolutionize Gene Editing Unlock CRISPR-Cas9 Secrets

Word Count Emoji
570 words
Reading Time Emoji
3 mins read
Updated at Emoji
Last edited on 14th Jun 2024

Table of content

In a Nutshell 🌟

The CRISPR-Cas9 system, borrowed from prokaryotes, is like the "find and replace" function in a word processor, but for genes! Let's break it down.

CRISPR Basics

C.R.I.S.P.R: Like the crisps you munch on? Not really! It stands for Clustered Regularly Interspaced Short Palindromic Repeats. Here's what each word means

  • Repeats: Same base sequence pops up multiple times.
  • Short: Just between 23 and 47 base pairs. Tiny, right?
  • Clustered: All grouped together like a reunion.
  • Regularly Interspersed: Between these repeats are unique sequences called spacers. Think of them as dividers in a cookie box.
  • Fun fact: these spacers come from viruses that tried to attack the prokaryotes. It's like a genetic "Most Wanted" poster!
  • Palindromic: Reads similarly backward and forward (almost).

The Role of Cas9

  • It's a natural enzyme, acting like a DNA detective.
  • Its partner-in-crime is guide RNA (gRNA) that's derived from a CRISPR array.
  • As it moves along DNA, it seeks out specific sequences to match with its gRNA.
  • Once it finds a match, it performs a snip-snip action, cutting through the DNA.

💡 Real-world example: Imagine a barcode scanner scanning products to find a match. Cas9 is the scanner, and the gRNA is the barcode it's looking for.

How Do We Use It for Gene Editing?

  • Scientists always wanted a tool like search and replace for genes. Enter CRISPR-Cas9!
  • Prime editing: An improved method using special RNA, pegRNA. It's kind of like CRISPR 2.0.
    • This RNA connects with modified Cas9, looking for target genes.
    • When found, instead of a double-cut, it makes a single cut (nick) in the DNA.
    • Using a feature of pegRNA, new genetic information is added, replacing the old.
    • Our body's natural repair system takes over from here, fixing any mismatches.

💡 Real-world example: It's like using an advanced software patch to fix bugs in a program. The software (CRISPR) searches for the bug (specific gene sequence), then patches it (modifies it)!

Unlock the Full Content! File Is Locked Emoji

Dive deeper and gain exclusive access to premium files of Biology HL. Subscribe now and get closer to that 45 🌟