Validity

How well the experiment measures what it is intended to measure (the aim) and does it relate to the hypothesis

Validity

How well the experiment measures what it is intended to measure (the aim) and does it relate to the hypothesis

Validity 2

• Data collected is valid because controlled variables were used

• Experiment investigated the aim

• frothing height could be influenced by inconsistencies in mixing or delay in measuring, affecting validity

Accuracy

Refers to how close measurements are to true value

Accuracy 2

• ruler to measure the froth height gave quantifiable results

• thermometer ensuring correct temperatures

• human error in reading height could alter results

Reliability

Consistency of results

Reliability 2

• Repetition of 3 test tubes per temperature

• same amount of concentration and measurement of spinach and solution

• average was calculated too to summarise data collected

Lock and key

Enzyme active site acts like a “lock” precisely shaped to fit a specific substrate “the key”

• the substrate fits perfectly without any changes made to the enzyme

Induced fit

Substrate binds to enzyme

enzyme goes under conformational change to better accommodate the substance

Which one is better

Lock and key provides foundational understanding of enzyme specificity

induced fit reflects dynamic nature of enzyme substrate interactions, supported by more recent experimental evidence.