Enzyme

Question 1

Structure of enzyme

Answer 1

Tertiary structure
-determines shape of active site
-complimentary to specific substrate
-biological catalyst
-catalyses reaction while remains unchanged

Question 2

How does enzyme work

Answer 2

Substrate bind to active site = enzyme substrate complex
-anabolic reaction to build molecules using energy
-catatonic reaction to break molecule releasing energy
-lowers activation energy for a reaction

Question 3

Lock and key + induced fit

Answer 3

Lock and key
-active site is in a fixed shape, only 1 shape of substrate fit

Induced fit
-active site can change shape slightly for similar shape substrate

Question 4

Different factors affecting substrate activity

Answer 4

Temperature
-low = low kinetic energy
-optimal = lots of collision
-too high = bonds vibrate too much tertiary structure break down

pH
-optimal = normal
-anywhere not optimal = denature

Substrate concentration
-increases until stagnant
-limiting factor is enzyme

Enzyme conc
-keep increasing

Question 5

Graphs of different factors affecting enzyme activity

Answer 5

https://l450v.alamy.com/450v/2xp0yp3/factors-affecting-enzyme-activity-illustration-factors-that-affect-the-activity-of-an-enzymes-include-temperature-substrate-concentration-ph-and-enzyme-concentration-2xp0yp3.jpg

Question 6

How to investigate rate of enzyme activity

Answer 6

Disappearance of substrate
Appearance of product

Question 7

Inhibitors

Answer 7

Competitive inhibitors
-bind to active site
-fewer enzyme to bind to
-reversible by enzyme
-as substrate conc increased this effect is decrease
-rate of enzyme substrate complex will still reach max but slower

Non-competitive
-bind to allosteric site
-permanently changes active site shape
-enzyme inactive
-does not change even if substrate conc increased
-rate does not ever reach max

Question 8

Graphs of inhibitor activity

Answer 8

https://resource.download.wjec.co.uk/vtc/2020-21/el20-21_20-10/images/l3-s3-graph.jpg

Question 9

Immobilising enzyme

Answer 9

Make enzyme inert (non-reactive)
-stuck on gel membrane, polythene
-reduce ability for poly-peptide chain to move = tertiary structure harder to denature
-stabilise enzyme - wider range of optimal pH + temperature

In industry
-reuse = cheaper + less time to make new enzyme
-can use wider range of temperature to further reduce cost

Medicine
-biosensor like glucose oxidase electrode
-detect level of glucose in blood