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43 Cards in this Set
- Front
- Back
What are living things made of? |
Thousands of different chemicals which are called organic because they contain the element carbon |
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What kind of compounds do organic and inorganic compounds contain? |
• Organic compounds contain carbon-carbon bond • Inorganic compound don't |
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What are the 4 types of organic molecules found I living organism? |
• Carbohydrate • Protein • Lipids • Nucleic acids (DNA) |
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What elements do carbohydrate contain? |
• Carbon • hydrogen • oxygen |
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What is the monomer of carbohydrate? |
• Monosaccharides • Most important and common is Glucose |
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What are the isomers of glucose? |
• Galactose • Fructose |
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How are disaccharides formed? |
• When two monosaccharides are joined together by GLYCOSIDIC BOND |
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What is the reaction called where two molecules combine to form a bigger molecules? |
Condensation reaction |
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What is the reaction where a big molecule is split into two smaller molecules? |
Hydrolysis |
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What are the three common disaccharides and what are they made from? |
Glucose + Glucose = Maltose Glucose + Fructose = Sucrose Glucose + Galactose = Lactose |
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What is starch broken by and into what? |
• Amylase • Maltose |
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Give 3 examples if polysaccharides? |
• Starch • Cellulose • Glycogen |
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What are lipids? |
• Mixed group of hydrophobic compounds • Carbon, hydrogen, oxygen, phosphorus |
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What are the most common types of lipids? |
Triglycerides and phospholipids |
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What is triglyceride made of and what are they used for? |
• 3 fatty acid + 1 glycerol • Joined by ester bond • known as fats or oil • insoluble in water(don't dissolve) > Used for storage > Insulation > Protection |
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Why are triglycerides not a good source of energy? |
Because they cannot be mobilised quickly as they are insoluble so not good for quick energy requirement |
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What does saturated mean? |
No C=C bond • High melting point • found in warm blooded animals • Room temperature they are solid |
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What does unsaturated mean? |
Has a C=C bond • Low melting point • Found cold blooded animals and plants • Room temperature are liquids |
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What is the structure of phospholipid? |
They have 2 fatty acid, a glycerol and a phosphate • Hydrophilic head • Hydrophobic tail |
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What type of bond are amino acids joined together by? |
Peptide bonds through condensation reaction |
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How are proteins made? |
Through polymerisation of amino acid in protein synthesis which takes place in ribosomes and requires a RNA template.
The sequence of amino acid in polypeptide chain is determined by the sequence of bases in the DNA |
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What is the primary structure of a protein? |
Sequence of amino acid in a polypeptide chain |
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What is the secondary structure of protein? |
• Held together by hydrogen bond to form backbone • Alpha helix • Beta sheet |
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What is the tertiary structure of protein? |
• Compact globular shape • polypeptide chain folded together • Every protein has a unique tertiary structure which is responsible for its properties and function |
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What is the quaternary structure of proteins? |
• Compose of more than one polypeptide chain • Arrangement of different chain |
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What are the 3 dimensional shape of protein? |
Globular and fibrous protein |
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What is the test for starch? |
• Add few drops of iodine to sample • Blue-black colour formed |
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Describe the test for reducing sugar |
• Add few drops of benedict reagent to sample • Shake and heat for a few minute in a water bath at 95 degrees • A coloured ppts indicates reducing sugar (brown/red) |
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Describe the test for non reducing sugar |
• First hydrolyse to monosaccharide • By boiling tube with dilute hydrochloric acid • To hydrolyse glycosidic bond • Add sodium hydrogen carbonate • Do the test for non reducing sugar |
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Describe the test for lipids |
• Emulsion test • Shake test sample with ethanol • Put into a test tube of water • A cloudy white emulsion is formed |
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Describe the test for protein |
• Add biuret solution to the sample • Shake • Turns lilac-purple |
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What are enzymes? |
Enzymes are biological catalyst that speed up the rate of reaction |
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How do enzymes work? |
1) Manipulate substrate in active site 2) Provide an alternative pathway 3) Lower activation energy |
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Describe the lock and key model of enzyme action |
• Active site is complementary to substrate • Substrate fits 'perfectly' • Binds with one substrate only |
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Describe the induced fit model |
• Enzyme is flexible • Active site can change shape • Isn't excited complementary to substrate • When substrate binds, active site changes shape to for the substrate • Distorts substrate molecule • Change into product |
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What are the factors that affect rate of enzyme? |
• Temperature • PH • Enzyme concentration • Substrate concentration • Inhibitors |
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How does temperature affect rate of enzyme reactions? |
• Organisms have an optimum temperature which they work best • Higher temperature increases the rate of reaction until it reaches the optimum temp • There's more kinetic energy • More molecules have enough energy to overcome activation energy
• At too high a temperature • Enzyme is denatured as • Weak hydrogen bond holding tertiary structure is broken • So enzymes lose specific shape becomes random coil • Substrate can no longer bind |
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How does PH affect the rate of enzyme reactions? |
There's an optimum PH at which enzymes work best • Increase in PH will increase the rate of reaction • Too high of an increase would denature the enzyme as the shape of enzyme would be changed • As well as the charge of the active site |
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How does enzyme concentration affect the rate of reaction? |
• As enzyme concentration increases the rate of reaction increases • More enzyme to catalyse the reaction • At very high enzyme concentration the substrate conc may be limiting • So the rate of reaction slows down |
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How does substrate concentration affect the rate of reaction? |
• Curve dependence • As substrate conc increases rate of reaction increases • More substrate molecule collides with enzyme so more reaction takes place • At higher conc the active site becomes Saturated with substrate • So there are few enzyme molecules • Adding more substrate won't make any difference |
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How does inhibitors affect rate of reaction? |
Inhibitors work by reducing the rate of reaction. They are used artificially as drugs, pesticides and research tools. 2 types:
Those that bind weak- reversible inhibitor
Those that bind strongly-irreversible inhibitor |
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What are the 2 types of inhibitor? |
1) Competitive inhibitor- - similar structure to normal substrate molecule - so compete with substrate for active site
2) Non-competitive inhibitor - different structure to normal substrate - do not fit the active site - bind to other site other than the active site - change the shape of the whole enzyme including active site - substrate can no longer bind to enzyme |
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Distinguish between enzyme and receptors |
- Enzyme had an active site, receptors have binding site - In enzyme the substrate is changed and released as a different molecule - In receptors the substrate remains the same |