9 & 10 - Enzymes + Higher Level En

Enzyme

Biological (or organic or protein) catalyst

Metabolism

(All) chemical reactions in a cell (or organism)

Distinguish between the terms anabolic and metabolic

Anabolic: building up large molecules from small molecules or (a reaction) using energy

Catabolic: breaking down large molecules to small molecules or (a reaction) releasing energy

Describe the active site theory of enzyme action to explain enzyme function and specificity

Active site has a complimentary shape to only one substrate / active site changes shape (or induced fit) to accommodate substrate / enzyme substrate complex is formed / product formed / enzyme unchanged or active site changes back to original shape

What is the function of the active site of an enzyme?

To combine with the substrate or convert substrate to product

Give the products of each of the following enzymes:

i) Amylase

ii) Lipase

iii) Protease

i) Maltose

ii) Glycerol and fatty acids

iii) Amino acids or peptides

To which group of biomolecules do enzymes belong

Protein

Specificity (in terms of enzymes)

Enzymes can only act on one substrate

Give two factors that affect the function of an enzyme

pH / temperature

What is a denatured enzyme?

An enzyme that has lost it’s function

Is the reaction shown below an anabolic reaction or a catabolic reaction? Explain your answer.

Catabolic - Large molecule broken down into smaller molecules or energy released

Give one example of a catabolic enzyme and one example of an anabolic enzyme

Catabolic: Amylase

Anabolic: Polymerase

Explain the term optimum activity in relation to enzymes

Working at its maximum rate

What is an immobilised enzyme?

An enzyme that has been trapped in an insoluble material (or attached to each other)

Give one advantage of immobilised enzymes

Pure product formed or more stable than free enzyme or reusable

Describe how enzymes may be immobilised

Enzyme added to (sodium) alginate / calcium chloride added to solidify gel

Identify the cell organelle where enzymes are produced

Ribosome

In the context of cell metabolism, what does NAD stand for?

Nicotinamide Adenine Dinucleotide

Name two types of particle that are transferred by NAD

Electrons (e^-)

Protons (or hydrogen ions or H⁺)

Identify X and Y

X = lipase

Y = glycerol

Suggest why enzymes are included in washing powder

To break down food-based (or other biological) stains

Write notes on the following topics. You are required to make a minimum of three points concerning each topics.

i) Metabolism

(The sum of) all reactions in cell (or organism) / controlled by enzymes / catabolism explained / anabolism explained

Write notes on the following topics. You are required to make a minimum of three points concerning each topics.

ii) ADP

Adenosine di-phosphate / a low energy (molecule) /

+ phosphate (P) / + energy / ATP formed

Comment upon enzymes molecular shape

Folded (Globular)

Is the conversion of ADP to ATP catabolic or anabolic?

Anabolic

Bioprocessing

The use of enzyme-controlled reactions to produce a product

Bioreactor

Vessel in which products are made by cells (or organisms)

Give one application of a named immobilised enzyme. In your answer, refer to substrate, enzyme and product

Lactase - converts lactose into glucose and galactose

or

Glucose Isomerase - converts glucose into fructose

Experiment: Enzyme immobilisation

Name the enzyme you immobilised

Sucrase (in yeast)

Experiment: Enzyme immobilisation

Describe the procedure you used to immobilise the enzyme

Dissolved alginate in water and added yeast / dropped into solution of calcium chloride / beads hardened or beads filtered or rinsed

Points may be obtained from an appropriately labelled diagram

Experiment: Enzyme immobilisation

Describe how you examined the application of the immobilised enzyme

Place beads of immobilised enzyme into a separating funnel / add a solution of yeast and water into a second separating funnel / pour sucrose solution into each separating funnel / test the products by letting them drip onto glucose strips / immobilised yeast is slower to start forming glucose / glucose is formed more quickly by the non-immobilised yeast

Experiment: Investigation of the effect of heat denaturation on enzyme activity

Name the enzyme you used, its substrate and its product

Enzyme: Catalase

Substrate: Hydrogen Peroxide

Product: Oxygen + water

Experiment: Investigation of the effect of heat denaturation on enzyme activity

Describe how you carried out the investigation. Use a labelled diagram if necessary.

Boil enzyme / unboiled enzyme / place enzyme solution into a graduated cylinder / pH 9 buffer added / placed in water bath at 25^oc / left for a time / noted production of foam or not

Experiment: Investigation of the effect of heat denaturation on enzyme activity

Describe the results of this investigation.

Boiled enzyme showed no activity (did not produce foam)

Fresh enzyme showed activity (produced foam)

Experiment: Investigation of the effect of pH on the rate of activity of an enzyme

Name the enzyme you used in this investigation

Catalase

Experiment: Investigation of the effect of pH on the rate of activity of an enzyme

Describe how you varied the pH in this activity

Added different pH buffers

Experiment: Investigation of the effect of pH on the rate of activity of an enzyme

Describe how temperature was kept constant during this investigation

Waterbath

Experiment: Investigation of the effect of pH on the rate of activity of an enzyme

Briefly describe how you measured the rate of enzyme activity

Determined the volume of foam / produced in a set period of time

Experiment: Investigation of the effect of pH on the rate of activity of an enzyme

Draw a labelled diagram of the apparatus that you used in this investigation

Diagram: graduated cylinder with liquid

Labels: Graduated cylinder / Enzyme / waterbath / foam / washing up liquid / buffer

Experiment: Investigation into the effect of temperature on the rate of enzyme action

Name the enzyme that you used

Catalase

Experiment: Investigation into the effect of temperature on the rate of enzyme action

Name the substrate of this enzyme

Hydrogen Peroxide

Experiment: Investigation into the effect of temperature on the rate of enzyme action

Why was it necessary to keep the pH constant in the course of this investigation?

To eliminate it as a possible influence on rate or only one variable

Experiment: Investigation into the effect of temperature on the rate of enzyme action

How did you vary the temperature in the course of the investigation?

Waterbaths

Experiment: Investigation into the effect of temperature on the rate of enzyme action

Use the axes below to summarise the results of your investigation. Do this by

1. labelling the axes,

2. drawing a graph to show how the rate of enzyme action varied with temperature.