B3 - Tissues And Organ Systems Flashcards
Enzymes
Special biological catalysts that speed up reactions.
Different enzymes have ___ optimum ___.
optimum , pHs
Calculation for rate of an enzyme-controlled reaction
1 / Time taken for end point to be reached
What does the rate of an enzyme-controlled reaction mean?
How quickly a reaction occurs.
Comparing the rates of reactions taking place under different conditions can enable you to …
determine the optimum conditions for an enzyme.
Carbohydrates are made up of …
units of sugar
Simple sugars
Carbohydrates containing only one or two sugar units.
Carbohydrates and Benedict’s solution
Carbohydrates turn blue Benedict’s solution brick red on heating.
Consistency of Lipids
Three molecules of fatty acids bonded to a molecule of glycerol.
Lipids and Ethanol
Ethanol test indicates the presence of lipids in solutions.
Consistency of Protein
Molecules made from long chains of amino acids.
Protein and Biuret reagent
Protein turns Biuret reagent from blue to purple.
What is a catalyst?
A substance that increases the rate of chemical reactions without being used up.
What are Enzymes, exactly?
Proteins. They fold their amino acid chains into an active site, which matches the shape of a specific substrate.
The ___ binds to the ___ ___ and the reaction is ___ by the ___
The SUBSTRATE binds to the ACTIVE SITE and the reaction is CATALYSED by the ENZYME.
What is metabolism
The sum of all the reactions in a cell or in the body.
Factors affecting enzyme activity
Temperature and pH
Effect of high temperatures on an enzyme
High temperatures denature the enzyme, changing the shape of the active site.
Effect of pH on an enzyme
pH can affect an enzyme’s active site and make it work either very efficiently or stop it working altogether.
[True or False] Enzymes are killed when conditions surpass either their optimum temperature or pH
False
Enzymes are molecules, not living things themselves. Instead, they denature past their optimum temperature and/or pH.
What does digestion involve?
Involves the breakdown of large insoluble molecules into soluble substances that can be absorbed into the bloodstream across the wall of the small intestine.
How digestive enzymes are produced
By specialised cells in glands and in the digestive system lining.
Effect of amylase on carbohydrates
Catalyses the breakdown of carbohydrates to simple sugars.
Effect of protease on protein
Catalyses breakdown of protein to amino acids.
Effect of lipase on lipids
Catalyses breakdown of lipids to glycerol and fatty acids.
Purpose of Hydrochloric acid in the stomach
It gives the suitable pH conditions for protease secreted in the stomach to work efficiently during digestion.
Purpose of alkaline bile in digestion
Neutralises the hydrochloric acid and gives ideal pH conditions for the enzymes from the pancreas and small intestine to work well during digestion.
[True or False] Bile is an enzyme because it breaks down fat molecules.
False.
It EMULSIFIES fat molecules into tiny droplets, increasing the surface area for lipase to increase the rate of digestion.
