Enzymes Flashcards
Define Metabolism
the sum of the chemical reactions that take place within each cell of a living organism
State and define the 2 types of metabolic reactions
catabolic-reactions that break down large molecules
anabolic-reactions that build complex molecules from simple ones
Give an example of anabolic reactions
an example of catabolic reactions are the formation of tissues and organs.Different cell components are synthesised and assembled in cells,which then form tissues and organs
Give an example of catabolic reactions
Example:Digestion
large molecules produced by digestion make up smaller molecules such as starch
Define extracellular and intracellular enzymes
extracellular-enzymes that work outside the cell that made them
intracellular-enzymes that work inside the cell
Explain how catalase catalyses intracellular reactions
Catalase is involved in the breakdown of H2O2 into water and oxygen.Catalase ensures this catabolic reaction occurs quickly,preventing it from accumulating as its toxic.
Explain how amylase catalyses extracellular reactions
Digestion of starch
Amylase breaks down starch into maltose(disaccharide)
Amylase is produced by salivary glands and pancreas (into pancreatic juice).
Maltose broken down into glucose by maltase
Explain what the temperature coefficient is
It shows how much rate of reaction increases when temp is increased by 10°C.
Eg:
If Q10 is 2 the rate of reaction is doubled when temperature is increase by 10°C
Draw a graph showing the effect of temp on enzyme action
Graph showing a line increasing reaching an optimum and decreases sharp decrease
Explain how an enzyme changes when temperature is increased
Increasing temperature gives the molecules more kinetic energy
• This gives more successful collisions
• More enzyme / substrate complexes form
• Enzymes have an optimum temperature
• Above this the hydrogen bonds that hold the tertiary structure are affected
• The 3D shape changes and the active site is distorted
• The change in shape prevents the substrate from binding
• The effect of high temperature is known as denaturing
• This is irreversible
Explain how changing PH affects enzyme shape.
When PH is decreased there are more H+ ions present. This affects ionic bonding and h bonds
The H+ ions will interact with the polar parts of an enzyme (delta negative). This will change the tertiary structure of the enzyme and substrate will no longer fit.
Explain how changing the substrate concentration affects enzyme structure/action
As the enzyme substrate concentration increases the rate of enzyme action increases.
The more substrate molecules present, the more frequent successful collisions.
Draw and label a graph showing affect of PH and substrate conc.
PH-symmetrical increases reaches optimum and decreases.
Substrate concentration - graph increases gradually and platues
Define cofactor
A non-protein substance bound to an enzyme, helping it with its function
explain how enzymes speed up reactions and how activation energy is lowered
activation energy lowered when an enzyme substrate complex is formed.
rate of reaction speeds up when activation energy is lowered.
