As Biology test Biological molecules Flashcards
Three examples of monomers
Amino acid
Glucose
Fructose
Galactose
What is a monomer?
Is an individual molecule that bonds with a series of others to make a polymer chain
What is a polymer?
A compound made of several repeating units or monomers bonded together
Three examples of polymers
Cellulose
Glucagon
Starch
What is hydrolysis?
Is the chemical interaction with water and a compound which results in the decomposition of this compound.
What is condensation?
A chemical reaction in with a joining of two organic compounds results in the productions and release of water
Draw an alpha glucose molecule.
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Draw a beta glucose molecule,
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Draw a maltose molecule.
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Describe the benedicts test.
Place 2cm3 of the sample in a test tube as well as 2cm3 of the Benedict’s reagent (greenish-blue). Place the test tube in a boiling tub for 2 minutes. If the colour of the solution is redish orange, it is a reducing sugar. If it stays a greenish/blue colour, it is a non reducing sugar.
Describe the structure of starch.
It consists of 2 polysaccharides amylopectin and amylose. The structure is long chains of alpha glucose linked together by glycosidic bonds.
Give three properties of starch.
- insoluble in water (since it will not change the water potential of solutions, it’s grate for storage in plants)
- the helical shape is compact so able to store a lot of glucose
- the branches make it easy to hydrolyse and release glucose monomers for energy
Draw a glycogen molecule.
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Describe the structure of cellulose.
Consists of adjacent chains of long polysaccharides of glucose joined by beta 1-4 glycosidic bonds. These strands are joined by hydrogen bonds to form microfibrils.
Give three properties of cellulose.
- gives strength and sturdy structure to the plant due to the hydrogen bonding between each strand forming microfibrils
- the beta glycosidic bonds requires a specific enzyme to break it so its not easy to break down
- the hydrogen bonds prevent water from entering the fibrils and causing hydrolysis so it’s hard to break down.
Draw a glycerol molecule.
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Draw a polyunsaturated fatty acid.
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Draw a saturated fatty acid.
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Draw an ester bond.
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Draw a simple diagram of a triglyceride
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Draw a phospholipid
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Describe the emulsion test for lipids
Put 2cm3 of the sample in a test tube and add 2cm3 of ethanol to it till it dissolves. The. Add 2cm3 of water. If the sample has lipids, the final solution will produce a white precipitate.
Draw an amino acid
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Draw a dipeptide
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What is a R group?
Is at hydrogen or carbon chain that is bonded to the alpha carbon and determines the type and characteristics of the amino acid it is.
Describe the primary structure of a protein.
A sequence of amino acids in a polypeptide chain.
Describe the secondary structure of a protein
Is the folding of the polypeptide chains due to the hydrogen bonding creating an alpha helix or beta sheet
Describe the tertiary structure of a protein.
A 3-D structure is formed from a further folding of the alpha helicies which is maintained by fairly strong disulfide bonds,ionic bonds between carboxyl and amino groups and hydrogen bonds.
Describe the quaternary structure of a protein
The combination of a number of different polypeptide chains linked in various ways and non-protein groups into a large complex protein molecule
Describe the biuret test for proteins.
Place a sample with equal volume of sodium hydroxide solution in a test tube. Ten add a few drops of dilute copper sulfate solution and mix gently. If the solution turns purple, it is a protein and if it stays blue, it isn’t.
List three properties of globular proteins.
- have complex tertiary and sometimes quaternary structures
- folded into a spherical/globular shape
- usually soluble (because the hydrophobic side chains are in the centre of the structure).
