Get an answer in 5 minutes

We'll notify as soon as your question has been answered.

Plus iconAsk a question to our educators
BIOLOGY
Asked by Zahid

I keep struggling with what enzymes are and on my last exam all my questions wrong were about enzymes even though I had written notes down please help?

Hi Zahid, Enzymes at GCSE level are really simple once you wrap your head around them. Enzymes are biological catalysts. This means they speed up chemical reactions within your cells to keep you alive! Enzymes work by fitting their specific substrate(s) (sort of like reactants) into their active site. What this means is that the enzyme/substrate system works like a lock and key, where the enzyme is the lock, the substrate is the key. The enzyme is shaped in such a way that there is a section of it that is the exact shape of its substrate. The enzyme is specific to its own substrate. The substrate binds with the enzyme at this specifically shaped spot (the active site) and the substrate is released, after being broken down into two smaller products (degradation) or two smaller substrates are combined into one larger product (synthesis). The shape of the enzyme does not change as a result of this, so it can be reused for another substrate. Enzymes work best at certain temperatures and pH levels. For human enzymes, the temperature is around 37°C (which is why your body is at this temperature). The pH varies, however, for example this is why your stomach contains acid - to accommodate for the enzymes in your stomach. However, when the conditions an enzyme is in exceed tolerable limits of temperature and pH, they become denatured. This means that the shape of their active site has changed, so they cannot bind with their specific substrate any longer. This means the reaction happens much slower, and eventually kills the organism. This is why body temperature is so important! Human enzymes tend to denature at around 60°C. And since the optimum pH changes, the tolerable limits for each enzyme change too. Denaturing is irreversible. When an enzyme gets too cold, it does not denature, but the enzyme activity slows down and eventually stops. When the organism is heated again however, the enzyme activity eventually returns to normal. I hope this helped in some way! If you have any more questions, feel free to ask me and I’ll do my very best to answer them. Thanks, Graeme

Graeme's profile picture
Verified
Graeme Docherty
·

177 students helped

Get an answer in 5 minutes

We'll notify as soon as your question has been answered.

Plus iconAsk a question to our educators

Badge showing the text 'New'Learn with Video Lessons

A-Level Physical Chemistry
1hr 9m · 7 videos
Ibrahim's profile picture
Ibrahim Dangra
·

608 students helped

A-Level Physical Chemistry
GCSE Maths - Numbers
1hr 28m · 8 videos
Paja's profile picture
Paja Kruzikova
·

441 students helped

GCSE Maths - Numbers
How to Analyse (Unseen) Poetry
20m · 7 videos
Nina's profile picture
Nina Modak
·

2k students helped

How to Analyse (Unseen) Poetry
COVID-19 Guidance For Students
30m · 5 videos
Jackie's profile picture
Jackie Jones
·

800 students helped

COVID-19 Guidance For Students

Premium video lessons available now on Scoodle

50% discount available

Scoodle's video lessons make learning easy and fun. Try it for yourself, the first lesson is free!