1) Add a sample of the solution to be tested into a test tube and add an equal volume of sodium hydroxide solution. 2) Add a few drops of dilute copper (II) sulfate solution and mix gently. 3) A colour change from blue to purple indicates a protein
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What is in Biuret reagent?
Sodium hydroxide and copper (II) sulfate solution
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What elements make up amino acids?
Carbon, hydrogen, oxygen, nitrogen, sometimes sulfur
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What is the primary structure of a protein?
The number and sequence of amino acids in the polypeptide chain
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What determines primary structure?
The gene sequence
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What is the secondary structure of a protein?
The shape that the polypeptide folds into, caused by hydrogen bonding between O and H of adjacent amino acids. Shapes are either alpha helix or beta pleated sheet
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What is the tertiary structure of a protein?
The 3D shape which the alpha helix/beta pleated sheet is folded into
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What is the quaternary structure of a protein?
The arrangement of different polypeptide chains within the protein
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Give an example of a protein with quaternary structure
Haemoglobin, collagen, insulin
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What bonds are expressed in primary structure?
Peptide bonds
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What bonds are expressed in secondary structure?
Hydrogen bonds
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What bonds are expressed in tertiary structure?
Disulfide bridges, ionic bonds, hydrogen bonds
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What bonds are expressed in quaternary structure?
Ionic bonds, disulfide bridges
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Give an example and function of fibrous proteins
Collagen, for structural functions
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What is the structure of a fibrous protein?
Long chains which run parallel to one another, linked by cross bridges. They form very stable, insoluble molecules
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Give an example and function of globular proteins
Enzymes, e.g. amylase, for metabolic functions
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What is the structure of a globular protein?
It has a 3D shape to carry out metabolic functions and is soluble
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What is ATP short for?
Adenosine Triphosphate
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What are the 3 parts of ATP?
Adenine- a nitrogen containing base, Ribose- A pentose sugar, Phosphates- 3 of them
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Define metabolism
Total of all anabolic and catabolic reactions in an organism
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Define metabolic pathway
The sequence of enzyme controlled reactions
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Define specificity in relation to enzymes
The enzymes catalyse 1 reaction only
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What is a substrate?
The molecule the enzyme works on
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Give 4 ways in which enzymes work
Lower activation energy, allow reaction to occur in smaller steps, bring substrates together in correct sequence, induced fit
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Other cards in this set
Card 2
Front
Describe the biuret test
Back
1) Add a sample of the solution to be tested into a test tube and add an equal volume of sodium hydroxide solution. 2) Add a few drops of dilute copper (II) sulfate solution and mix gently. 3) A colour change from blue to purple indicates a protein
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