Biological Molecules Flashcards
What is a condensation reaction
Two monomers join together and lose a molecule of water
What is a hydrolysis reaction
Two monomers are broken apart and a molecule of water is added
What is the test for reducing sugars
Add Benedict’s reagent and heat the mixture a positive result is it goes orange-brown
What is the test for starch
Add iodine solution and shake a positive test is blue-black colour
What is the test for lipids
Add ethanol and water then shake. A positive test shows a cloudy white colour
What is the test for proteins
Buirets test (sodium hydroxide and copper II sulfate. A positive result shows a purple colour
Carbohydrates bond
Glycosidic bond
Lipid bond
Ester bond
Protein bond
Peptide bond
Starch’s structure
-alpha glucose monosaccharides
-branched or unbranched
Glycogen structure
-Found in animals and bacteria
-highly branched
Cellulose
-made of beta glucose
-unbranched
-hydrogen bonds
-cross linkages between adjacent chains
Triglycerides structure
-three fatty acids
-glycerol
Triglycerides structure rated to properties
-low mass to energy ratio so good storage molecules
-doesn’t affect osmosis as they are insoluble and non-polar
Phospholipids
-two fatty acids
-glycerol
-phosphate
-hydrophilic head=interacts with water
-hydrophobic tail=interacted with fat
Protein structure
Primary structure- amino acid monomers joining making a polypeptide
Secondary structure-gains hydrogen bonds causing it to twist into a 3D shape
Tertiary structure- contains disulphide bridges, ionic bonds and hydrogen bonds
Quaternary structure- form complex molecules such as Haemoglobin
Induced fit model
The enzyme doesn’t have to be very specific to the substrate. It can mild around the substrate and change the shape of its active site
Temperatures effect on enzyme action
A rise in temperature means an increase in kinetic energy making a higher frequency of collisions of enzymes and substrates. When the temperature gets above the optimum it causes bonds (hydrogen) to break causing the active site of an enzyme change shape and denature.
Ph effect on enzyme action
Enzymes can only work at there optimum ph of the ph is changed it will alter the charge on the amino acids breaking the bonds so the substrate can’t attach
Concentration affect on enzymes
If you increase the concentration of either the substrate or enzyme then the rate of reaction will be increased up until they have no more to bind to
Competitive inhibitor
They have a similar structure to substrates so that they can occupy the active site of an enzyme . It is not permanently attached so can be replaced
Non competitive inhibitors
They attach themselves to a binding site of an enzyme not the active site. They alter the shape of the enzyme so the substrate can no longer attach
A DNA nucleotide
-phosphate group
-base( A T C G)
-Pentose sugar (deoxyribose)
A RNA nucleotide
-phosphate group
-base ( A U C G )
-Penrose sugar (ribose)
