Biology HL

Chapters

553

Notes

Theme A - Unity & diversity

Theme B - Form & Function

Theme C - Interaction & Interdependence

Theme D - Continuity & Change

Biology HL

Theme B - Form & Function

Unlocking Protein Secrets: Impact of pH & Temperature

429 words

3 mins read

Last edited on 14th Jun 2024

Proteins have a unique three-dimensional shape stabilized by interactions between the R-groups of amino acids.
Like the pieces of a 3D puzzle, these bonds and interactions keep the protein in its functional form. Imagine a delicately folded origami – that’s our protein.

Denaturation is like unfolding our origami or breaking the puzzle. It means the protein loses its original shape due to the breaking of bonds/interactions.
Once a protein is denatured, it usually can't refold back. Like when you scramble an egg, you can't unscramble it!
Denatured proteins can become insoluble. Imagine milk turning into cheese-like curd when it's spoiled.

Heat🌡️
- It causes the protein to shake and vibrate, breaking the bonds.
- Not all proteins are equally sensitive. Some proteins, like those in microorganisms in volcanic springs, can handle heat up to 80°C.
  - Fun Fact: DNA polymerase from Thermus aquaticus, a microorganism found in hot springs, loves the heat at 80°C. That's why we use it in biotechnology.
- Most proteins, however, will denature at much lower temperatures. Think about how an egg white changes from clear to white when cooked!
pH Levels🍋
- Extremes, whether too acidic or too alkaline, can alter proteins.
- The reason? Changes in pH can break or form ionic bonds within the protein.
- Real-World Example: Our stomach is super acidic (pH ~1.5). Yet, there’s an enzyme called pepsin that thrives in this environment and helps digest proteins.

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

Biology HL

429 words

3 mins read

Last edited on 14th Jun 2024

Proteins have a unique three-dimensional shape stabilized by interactions between the R-groups of amino acids.
Like the pieces of a 3D puzzle, these bonds and interactions keep the protein in its functional form. Imagine a delicately folded origami – that’s our protein.

Denaturation is like unfolding our origami or breaking the puzzle. It means the protein loses its original shape due to the breaking of bonds/interactions.
Once a protein is denatured, it usually can't refold back. Like when you scramble an egg, you can't unscramble it!
Denatured proteins can become insoluble. Imagine milk turning into cheese-like curd when it's spoiled.

Heat🌡️
- It causes the protein to shake and vibrate, breaking the bonds.
- Not all proteins are equally sensitive. Some proteins, like those in microorganisms in volcanic springs, can handle heat up to 80°C.
  - Fun Fact: DNA polymerase from Thermus aquaticus, a microorganism found in hot springs, loves the heat at 80°C. That's why we use it in biotechnology.
- Most proteins, however, will denature at much lower temperatures. Think about how an egg white changes from clear to white when cooked!
pH Levels🍋
- Extremes, whether too acidic or too alkaline, can alter proteins.
- The reason? Changes in pH can break or form ionic bonds within the protein.
- Real-World Example: Our stomach is super acidic (pH ~1.5). Yet, there’s an enzyme called pepsin that thrives in this environment and helps digest proteins.

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