Proteins, catalysts andenzymes

WALT: To understand the role of enzymes.

WILF: Describe what a protein is and list uses in the body. (C)Describe the role of enzymes as biological catalysts. (B)Explain how enzymes work in reference to the lock and key hypothesis. (A/A*)

Keywords

CatalystsEnzymesActive siteSubstrate

Thursday 13 April 2023

ProteinsProteins are very important in your body.

They are made up of long chains of amino acids.

Amino acids

(monomer)

Protein (polymer)

ProteinsProteins carry out a range of functions in the body:

~ structural e.g. Muscle tissue

~ hormones e.g. Oestrogen

~ antibodies

~ enzymes

B1 Link

!

Hormones and the menstrual cycle (2.3)

KeywordsOvulationPeriodFSHOestrogenProgesterone

C: Name the structures in the body that release hormones.B: Describe what the menstrual cycle is and its average length.A/A*: Explain the roles of FSH and oestrogen in the menstrual cycle.

Controlling the rate of reactionsThe rate of a chemical reaction can be increased by using chemicals called catalysts.

A catalyst speeds up the rate of reaction but it is not used up in the reaction.

e.g. Iron is the catalyst used in the production of ammonia.

EnzymesEnzymes are biological catalysts.

They increase the rate of chemical reactions in the body.

They are specific.

The long amino acid

chain is folded

forming a specific 3d

shape

1) Build small molecules into large molecules:e.g. Amino acids Proteins OR Glucose Starch

2) Break large molecules down into smaller ones:e.g Starch Glucose OR Proteins Amino acids

3) Change one molecule into anothere.g. Sugars: Glucose Fructose

Enzymes

All of these reactions are speeded up by enzymes!

Substrate molecules

EnzymeActive site

Product

The ‘lock and key’ hypothesis

Reaction happens (bonds either made or broken)

Enzymes have a specific 3D structure

Enzyme-substrate complex

The ‘lock and key’ hypothesisTasks: 1. Glue in and label your diagram which illustrates how enzymes work.2. Using the keywords below explain:a) how enzymes work b) why they are specific. Keywordsenzyme substrate active site 3D shape specific reaction product enzyme-substrate complex

Hydrogen PeroxideHydrogen peroxide is a toxic chemical produced as a by-product to the metabolic reactions (chemical reactions) in our cells.It has to be broken down into the harmless products.The enzyme catalase speeds up this reaction.

 Catalase

2H2O2 --------------> 2H2O + O2

Hydrogen Peroxide1.Catalase is an enzyme found

in liver tissue. Define the term enzyme.

2.Catalase breaks down hydrogen peroxide into oxygen and hydrogen. What are the substrates and products in this reaction?

3.Explain the importance of this reaction in the body.

4.Manganese (IV) oxide is an industrial catalyst. Look at the graph on pg 165 and describe its effect on the breakdown of hydrogen peroxide.

Enzymes Summed Up!A catalyst will speed up a reaction...

Living organisms produce biological catalysts called...

All enzymes are made up of...

The substrate of an enzyme binds to the...

Each type of enzyme has a specific...

...active site.

...proteins.

...3d shape.

...but is not used up itself.

...enzymes.