2.7-2.14 Biological Molecules Flashcards
What are lipids made up of?
carbon
hydrogen
oxygen
What are carbohydrates made up of?
carbon
hydrogen
oxygen
What are proteins made up of?
carbon
hydrogen
oxygen
nitrogen
Describe the structure of carbohydrates
Can be a monosaccharide, disaccharide or polysaccharide.
Monosaccharide:
single sugar (e.g. fructose, glucose)
Disaccharide:
Two sugar molecules linked (e.g. maltose, sucrose)
Polysaccharide:
Many sugar molecules linked (e.g. starch, glycogen)
Describe the structure of lipids
most made of triglyceride
one glycerol molecule chemically bonded to three fatty acids
lipids are fats when solid at room temperature and oils when liquid at room temperature
Describe the structure of proteins
long chains of amino acids
there are 20 different types of amino acids
Describe the test for glucose
The test for glucose involves adding Benedict’s solution to the sample and heating it in a boiling water bath.
A positive result is a color change from blue to brick red.
Describe the test for starch
The test for starch involves adding drops of iodine solution to the food sample.
A positive result is a color change from orange-brown to blue-black.
Describe the test for protein
The protein food test involves adding drops of Biuret solution to the food sample.
A positive result is a color change from blue to violet/purple.
Describe the test for lipids
The test for lipids involves mixing the food sample with ethanol, straining it, and then adding the ethanol solution to cold water.
A positive result is a cloudy white emulsion forming.
What is an enzyme?
An enzyme is a protein that acts as a biological catalyst to speed up the rate of a chemical reaction.
What is an enzyme-substrate complex?
The enzyme-substrate complex is formed when a substrate attaches to the active site of an enzyme.
Define the term denatured
When an enzyme is denatured this is the process of an enzyme losing its specific shape and becoming inactive due to high temperatures or unsuitable pH
What happens to enzymes at low temperatures?
At low temperatures, enzymes work slowly due to a lack of kinetic energy and collisions between the substrates and active sites.
How does increasing temperature towards the optimum temperature affect enzyme activity?
Increasing the temperature towards the optimum increases enzyme activity as the molecules have more kinetic energy, leading to more collisions with substrate molecules and a faster rate of reaction.
