Topic 1 - Key concepts in Biology Flashcards
Enzymes
Biological catalysts, they speed up reactions in living organisms
Large, complex, protien molecules
Catylysts
a substance that speeds up chemical reactions
What are the 2 types of enzymes?
Ones that break down large molecules ( polymers) and ones that synthesize new substances (needed by body) from smaller molecules
Polymers
A Chain of large repeating units called monomers
What are the 3 main types of food molecules? (nutrients)
Protien
Lipids (fats)
Carbohydrated (sugars)
these are all polymers
What do digestive enzymes do in humans, why ?
They turn the large molecules in our food into the smaller subunits they are made of. This then makes the molecules small enough to be absorbed by the small intestine
What are the molecules absorbed by the small intestine used for?
they now can be used to build the larger molecules that are needed in the cells and tissues
What is synthesis?
Building larger molecules from sub units
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What are monomers?
atoms or small molecules that bond together to form more complex structures such as polymers
What does protien break down into/ what are its monomers?
Amino acids
What does starch break down into/ what are its monomers?
Glucose molecules
What does Lipids break down into/ what are its monomers?
Fatty acids and glycerol
Why do we need enzymes?
They speed up digestion and sythesis in the body, which would otherwise happen very slowly or not at all
Where is Amylase found?
saliva and small intestine
What does amylase catylise?
Breaks down starch into small sugars
Where is catylase found?
most cells, especially liver cells
What does catylase catylise?
breaking down hydrogen peroxide made in many cell reactions into water and oxygen
where is starch synthase found?
Plants
Hwat reaction does starch synthase catalise?
synthessis of starch from glucose
Where is DNA polymerase found?
nucleus
what reaction does DNA polymerase calalise?
synthesis of DNA from its polymers
How do we mesure the amount of energy in food?
A Calorimeter
What is the active site ?
where the substrate of the enzyme fits at the start of a reaction
Biological catalysts
they speed up reactions in living organisms
How do you detect starch?
An iodine test, drop iodine onto the food.
What color does Iodine turn if it detects starch?
Deep purple / navy
What do you use to detect reducing sugars?
Benedicts solution
How do you test for sugars with benedicts solution?
Add an equal amount of benedicts solution to the food soution and place in a hot water bath for a few minutes.
What colors does benedicts solution turn when it detects reducing sugars?
Green = little sugars
orange = more sugars
Red= lots of sugars
What do you use to detect protein?
Biuret test
How do you use the biuret test to detect protien?
Mix potassium hydroxide with a food solution. then add two drops of copper sulfate.
What color does the biuret test turn when it detects protien?
Purple
what do you use to detect lipids?
The ethanol emulsion test
How do you do an ethanol emulsion test?
Food is mixed with the ethanol and is shaken. soem fo that mixture is then poured itno water and shaken. if it emulsifies there are lipids.
Chemical reagants
substances with specific properties used to identify food molecules
What determines the shape of an enzyme molecule?
the folding of the amino acid chain