Biological Molecules Flashcards
What chemical element are in carbohydrates and proteins and lipids
Carbohydrates - CHO
Lipids - CHO
Proteins - CHONS
What is the structure of carbohydrates, proteins and lipids
Carbohydrates- monosaccharides
Proteins- amino acids
Lipids- glycerol + 3 fatty acids
What is the test for starch
Iodine test
+ Blue/black
- Yellowy brown
What is the test for protein
Biuret reagent
+ Lilac
- Blue
What is the test for lipids
Emulsion test (ethanol + water)
+ milky white
- clear
What is the test for glucose
Benedict’s test
+ Brick red
- Blue
Prepare water bath at 75 degrees Celsius and place test tube in water bath for 5 mins
What is the role of enzymes
Biological catalysts in metabolic reactions that speed up reactions
Describe how enzymes work
The enzyme has an active site which is specific to the substrate molecule
They temporarily combine to form an enzyme-substrate complex
The enzyme puts tension in the substrate which lowers the activation energy needed for the reaction to take place
During the reaction the substrate is turned into a product
This is released from the enzymes active site and the enzyme molecule is left unchanged to catalyze more reactions
Describe how enzymes work
The enzyme has an active site which is specific to the substrate molecule
They temporarily combine to form an enzyme-substrate complex
The enzyme puts tension in the substrate which lowers the activation energy needed for the reaction to take place
During the reaction the substrate is turned into a product
This is released from the enzymes active site and the enzyme molecule is left unchanged to catalyze more reactions
What is the effect of high temperatures on enzymes
The enzyme denatures
The bonds holding together the shape of the active site and enzyme change
The substrate no longer fits into the enzyme so there is no enzyme-substrate complex formed so the reaction stops
What is the effect of pH on enzymes
Enzyme denatures Different enzymes have different optimum pHs and work best in different environments
E.g. Pepsin in stomach works best at pH 2 due to acidic conditions
