(D) Enzymes in Action Flashcards
What are enzymes?
A protein molecule that acts as a catalyst in a biochemical reaction
What are proteins made of?
Amino acids
What are amino acids?
Molecules that can combine to make proteins
What is the structure of an amino acid?
A central (Alpha) carbon atom with 4 chemical groups attached
What chemical groups are attached to the central(alpha) carbon in a amino acid?
- A hydrogen atom
- An amino group
- A carboxyl group
- A variable R group (side chain)
How many R groups and amino acids are there?
There are 20(multiple) different R groups so there are 20(multiple) different amino acids
What are the main types of amino acid?
- Polar/Hydrophilic
- Non-polar/Hydrophobic
- Acidic/Negatively charged R group
- Basic/Positively charged R group
Peptide bond
Bonds that link amino acids together
What is a condensation reaction?
A reaction that occurs between two amino acids and produces water as well as a peptide bond
What is a dipeptide?
When two amino acids are linked together by a peptide bond
What is a tripeptide?
When three amino acids are linked together by a peptide bond
What is a polypeptide?
When several amino acids are linked together by a peptide bond and a polypeptide with more than 50 amino acid is a protein
What is a protein structure and the types of protein structure?
A protein structure is the structure of a protein and there are 4 types;
* Primary
* Secondary
* Tertiary
* Quaternary
What is a primary protein structure?
A polypeptide chain/amino acid sequence
What is a secondary protein structure?
When a polypeptide chain forms a shape (secondary structure) usually a α-helix or a beta plated sheet
What types of secondary structures are there?
- α-helix
- Beta plated sheet
What are secondary protein structures held by?
Hydrogen bonds between -NH of one peptide and the -C=O of another amino acid
What are tertiary protein structures?
A secondary structure which folds into three dimensional shapes
What does a tertiary protein structure do?
Gives an enzyme the shape of it’s active site
What bonds hold a tertiary protein structure together?
- Peptide
- Hydrogen
- Ionic
- Disulphide bridge
What is a disulphide bond?
A bond that forms due to a oxidization reaction
What is an active site?
An active site is a a region on an enzyme that binds to a substrate
What is a substrate?
The molecule that binds and is broken down by the enzyme
What is denaturation?
When the tertiary structure(active site) of the enzyme is changed
What is a catalyst?
A substance that speeds up a reaction, enzymes are biological catalysts
What is catalytic activity?
Increase in the rate of a reaction caused by the inclusion of an catalyst
What is collusion theory?
For a reaction to occur;
* Particles have to collide
* Particles must have enough energy to react
What is activation energy?
The minimum energy required for a particles to react
What is the enzyme-substrate complex
When a substrate enters the active site, this forms the enzyme-substrate complex. Then the reaction occurs, converting the substrate into products
What is different(specific) about every enzyme?
Enzymes are specific because different enzymes have different shaped active sites
The shape of the active site is complementary to the shape of its substrate
How does an enzyme lower the activation energy it needs?
- More particles have the required energy needed
- There are mores successful collisions
- There is a faster reaction
How can the rate of reaction be measured?
The initial rate of reaction must be recorded
* Measuring the decrease in substrate
* Measuring the increase in product
What are the factors that affect enzyme activity?
- Temperature.
- pH
- Substrate and enzyme concentration
How does temperature affect enzyme activity?
The closer the temperature is to the optimum(37°C) the faster the rate of reaction
What happen to an enzyme if the temperature is below the optimum?
Below this, there is less energy so less collision so slower reaction
What happen to an enzyme if the temperature is above the optimum?
Above this, the enzyme starts to denature and the hydrogen bond in the enzymes start to break
How does the pH affect enzyme activity?
Most enzymes have an optimum pH between 7 and 8, if the pH is outside this range then enzyme activity decreases
How does the substrate and enzyme concentration affect enzyme activity?
Increase in substrate/enzyme concentration →
Increase in the rate of collisions →
Increase in the rate of reaction
How much can the substrate and enzyme concentration affect enzyme activity?
