6841539
Description
Flashcards by Loolah Delilah, updated more than 1 year ago
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Created by Loolah Delilah
about 8 years ago
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| Question | Answer |
| What is a mol? | One mol contains the same number of particles as there are in 12g of Carbon - 12 - A mole is the molecular mass expressed as grams |
| What is a molar solution? | A solution that contains one mol of solute in each litre of water |
| What are the 4 reasons carbon is the base of all life forms? | 1) It forms long chains 2) it is cyclic 3) it can form single, double or triple bonds 4) it readily forms bonds with other carbon atoms |
| What are the names of a) a single molecule b) many molecules | a) monomer b) polymer |
| What are a) single sugars b) paired sugars c) many sugars | a) monosaccharide b) disaccharide c) polysaccharide |
| What is the formula for a monosaccharide? | (CH2O)n - Where n can be any number from 3 to 7 |
| Name a pentose and 2 hexose sugars | Pentose - Fructose Hexose - glucose, galactose |
| What is an isomer? Give an example | An isomer is a different version of the same monomer - Eg a-glucose and b-glucose |
| What is reduction? What is a reducing sugar? | Reduction is the chemical reaction involving the gain of electrons or hydrogen - a reducing sugar is one that can donate electrons |
| What is the test for reducing sugars? | Benedicts test |
| Describe the test for a reducing sugar | 1) mix 2cm^3 of the sugar with equal amounts of benedicts reagent 2) heat for 5 minutes 3) a red colour indicates a reducing sugar |
| What is benedicts reagent and why is it used? | An alkaline solution of Copper(||) solution that creates a red precipitate of copper(||) when heated with a reducing sugar |
| What is the storage polysaccharide in plants | Starch |
| Why is starch used as the storage polysaccharide in plants? | 1) it is compact, so a lot can be stored 2) it is insoluble in water, meaning it will not affect osmosis, water balance, or diffuse out of cells 3) it is readily hydrolysed into a-glucose which is used in respiration 4) its many branched ends can be worked on simultaneously by enzymes meaning glucose monomers are released rapidly |
| What is the energy storage polysaccharide in animals and why is it different to that of plants? | Glycogen - similar but with more branched ends, so it is more readily hydrolysed as animals have a higher metabolic rate |
| What is the structural polysaccharide in plants? What monomer is it made out of? | Cellulose B-Glucose |
| What 3 structural aspects of cellulose make it so suited for its purpose? | It forms long branched chains that run parallel to each other. Hydrogen bonds act as cross links between the chains, adding strength They group into micro fibrils, which then also group to form fibres |
| What 3 atoms make up lipids? | Hydrogen, Carbon and Oxygen |
| What are the two types of lipids? | Triglycerides Phospolipids |
| What are the 4 roles of lipids on the body? | 1) Energy - they release twice the energy of carbohydrates 2) Waterproofing - insoluble in water 3) Insulation - slow conductors of heat mean they retain body heat 4) Protection - around delicate organs |
| Why are triglycerides called this? | 'Tri' means 3 fatty acids combined with glycerol |
| What bonds are formed by lipids in condensation reactions? | Ester bonds |
| What is the formula for glycerol? | CH2OH | CH2OH | CH2OH |
| What functional group attaches itself to the glycerol branch? | (-COOH) |
| What does the condensation of glycerol and 3 fatty acids create? | A triglyceride and 3 H2O |
| How many different types of fatty acid are there? | over 70 |
| If a fatty acid has only C-C bonds, what is it known as? | Saturated |
| If a fatty acid has a C=C bond or many C=C bonds, what are they known as? | Mono-unsaturated Poly-unsaturated |
| Why are mono-unsaturated and poly-unsaturated lipids oils rather than fats? | The double bonds cause the molecule to bend, meaning the chains cannot pack as close together |
| Name four structure/function properties of triglycerides? | 1) High ratio of energy storing C-H bonds to carbon atoms 2) low mass to energy ratio 3) Do not affect osmosis or water potential in cells 4) provide water when oxidised |
| What are phospolipids? | Similar to triglycerides but one fatty acid monomer is replaced by a phosphate molecule |
| What makes a phospolipid have different properties to a triglyceride? | While fatty acids repel water (are hydrophpobic), phosphate molecules attract water (are hydrophilic) - Therefore when placed near water, as they are polar they position themselves so the Hydrophillic head is as far away from the water as possibly and the Hydrophillic tail is as close as possible |
| What is the test for lipids? | 'Emulsion Test' 1) add 2cm^3 of sample to 5cm^3 of ethanol and shake 2) add 5cm^3 of water and shake again 3) cloudy white colour indicates a lipid |
| What are the 4 groups of a protein? | Amino group (-NH2) Carboxyl group (-COOH) Hydrogen atom (-H) R (side) group - that differentiate between the different amino acids |
| What bonds form between protein and where do they form? | Peptide bonds - join the carboxyl group of one amino acid with thy amino group of the other - release -OH from -COOH and -H from -NH2 to make a water molecule |
| What is the primary structure of proteins? | The sequence of amino acids |
| What is the secondary structure of proteins? | The shape of the polypeptide chain - Alpha helix - Beta pleated sheets |
| What 3 types of bonds maintain the structure of the tertiary structure of a protein? | Hydrogen bonds - many but weak Ionic - any carboxyl/amino groups form ionic bonds Disulfide bridges - strong |
| What two types of tertiary structure are there? | Fibrous and globular |
| What is Quaternary structure | Multiple peptide chains joining together, possibly with other molecules - Refers to the overall shape/makeup of the protein |
| What is the test for proteins? | 1) add equal amounts of test solution and SOH to test tube 2) add few drops of dilute copper sulfate (||) and mix 3) purple colour represents peptide bonds |
| what is an enzyme inhibitor? | a chemical that reduces the rate of enzymic reactions |
| state 3 properties of enzyme inhibitors | 1) are specific 2) block but don't destroy the enzyme 3) work in low concentrations |
| what makes some inhibitors irreversible? | they combine with the functional groups of the amino acids in the active site |
| how can be reversible inhibitors be reversed? | by increasing the substrate concentration or by dialysis |
| what are competitive inhibitors? | they compete with the substrate for the active site |
| what are non competitive inhibitors? | they bind elsewhere to the enzyme than the active site meaning they are not affected by substrate concentration |
| what is end point inhibition? | the first step of a reaction is controlled by the end point, meaning negative feedback is possible and the rate of substrate produced is controlled controlled by the need |
| what is the es complex | the enzyme substrate complex |
| explain the induced fit model | it proposes that the active site is changed by the enzyme by the proximity of a substrate, so that it fits the substrate like a glove |
| what four factors affect enzyme rate of reactions | temperature, pH, concentration of substrate, concentration of enzyme |
| how does substrate concentration affect an enzymic reaction? | too little - less than maximum rate right amount - maximum rate of reaction too much - no increase |
| how does enzyme concentration affect rates of reaction | too little - less than maximum rate of reaction right amount - maximum rate of reaction too much - no more increase in rate of reaction |
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