Using the pictures above as a reference describe and explain how hydrogen bonding between water molecules is related to its properties and roles in living organisms. (11)1) explain the terms: -primary structure; (1)-secondary structure (3) -tertiary structure (3)-quaternary structure and name two molecules who have a quaternary structure (4) 3) Name two biological molecules with cross-links. (2)4) Describe the structure of a collagen molecule (3)5) compare the structure and function of haemoglobin and collagen (4)6) describe the molecular structure of alpha-glucose as an example of a monosaccharide carbohydrate and describe the difference between beta-glucose and alpha-glucose; (3) 7) compare and contrast the structure and functions of starch (amylose) and cellulose (3)8) compare, with the aid of diagrams, the structure of a triglyceride and a phospholipid and explain how the structures of triglyceride, phospholipid and cholesterol molecules relate to their functions in living organisms (6)9) What are enzymes? (2)10) What are biological enzymes? (2)11) Describe and explain the lock and key hypothesis. (4)12) Explain the difference between the induced fit hypothesis and the lock and key hypothesis. (2)13) Describe and explain the effects of pH, temperature, enzyme concentration and substrate concentration on enzyme activity; (7)14) Explain the effects of competitive and non-competitive inhibitors on the rate of enzyme-controlled reactions, with reference to both reversible and non-reversible inhibitors (5)15) Explain the importance of cofactors and coenzymes in enzyme-controlled reactions (3)16) Metabolic poisons can be ______ __________, such as ethylene glycol also known as __________. Ethylene glycol is broken down in the _____ by the enzyme _______ _____________, which makes a toxic by-product called ______ _____. By consuming excess amounts of _______, it can act as an antidote. It does so by _____________ __________ the enzyme, which means less toxic by-products are made, but the person might get a serious case of alcohol poisoning, though much less likely to be fatal. (6)Potassium cyanide is another metabolic poison. Describe and explain the effects of consumption of potassium cyanide. (3)17) Define the term balanced diet. (1)18)[spoiler][IMG]http://t1.gstatic.com/images?q=tbn:ANd9GcRGuhYENFosMesZsgjIWO8cRap3dLBDFMCF7KAFWoAPBrgAk-4F[/IMG][IMG]http://t2.gstatic.com/images?q=tbn:ANd9GcQwfsmbx9JeoyRFPvQv1c0YMCs0g9G-LP_cS72VJAIzL2b7qjOB[/IMG] [/spoiler]Explain how the bmi might be unrepresentative of everyone using the pictures above as help. (4)19) Suggest how a person who has a balanced diet, good level of fitness/physical ability and is free of diseases might be unhealthy. (2)20) In Folks, a toxic chemical leaked into the fields where rabbits live. Hunters commonly hunt those places and take the rabbits home for dinner. Suggest what could happen with an explanation. (3)[IMG]http://1.bp.blogspot.com/_N6UEtG09iYo/S1fR1_JI5dI/AAAAAAAAAR4/RioyX9kaaVY/s640/foodweb.gif[/IMG]The biodiversity index value is very low. Explain the term biodiversity and suggest why. (3) Suggest the possible effects on the ecosystem of the hunting and poisoning and explain why. (4)21) Suggest why humans depend on plants and why being a vegetarian might have its disadvantages. (3)22) Outline how selective breeding is used to produce crop plants with high yields, disease resistance and pest resistance (4)23) Describe how the use of fertilisers and pesticides with plants and the use of antibiotics with animals can increase food production. (4)24) Describe the causes and means of transmission of malaria, AIDS/HIV and TB. (7)25) Describe the structure of antibodies in context with their function. (7)26) Compare and contrast active, passive, natural and artificial immunity; (3)27) Explain how vaccination can control disease (3)28) Compare and contrast the primary and secondary immune responses (3)29) Explain how biodiversity may be considered at different levels; habitat, species and genetic; (3)30) Define the terms classification, phylogeny and taxonomy (4)31) The common bat used to be classified as birds, the dolphins where classified as fish and the platypus as ducks. Suggest why. (3) Traditional classification systems were based originally on observable features but more recent approaches draw on a wider range of evidence to clarify relationships between organisms. Describe and explain what evidence they have and how modern classification systems differ from the traditional ones. (4) Suggest the possible advantaged of the modern classification system and explain how this clarifies evolution a bit better and helps with phylogeny using the pictures above. (2)32) Describe the differences between continuous and discontinuous variation, using examples of a range of characteristics found in plants, animals and microorganisms (5)33) Explain and describe the theory of evolution with reference to Darwins four observations. (7)

TOTAL: 152A*) 135A) 115B) 95C) 75D) 55

1)-ice is less dense than water, because the hydrogen bonds create a lattice, keep the molecules apart>which means that the water beneath is insulated, the water currents are still mobile>this means that aquatic organisms wont freeze to death and can move in water,-high surface tension because of the hydrogen bonds, >small insects such as pond skaters can walk on water,-lots of hydrogen bonds,>which means a lot of energy is required to break the bonds and evaporate it/high specific heat capacity,>very stable environment/habitat, no drastic changes in temperature, liquid at room temperature,>when people sweat they cool down, because evaporating it will need energy/heat,-water is dipolar,>it is soluble to ions/dipolar molecules,>it can form hydrogen bonds with OH groups,>aquatic plants can get their required minerals such as NO3-, for metabolic processes,

2)aThe sequence of amino acids,-2)b The amino acids chains are coiled or folded into alpha helix or b-pleated sheets. Hydrogen bonds between the molecules give it strength.

-2)cThe coils/folds themselves are coiled or folded even further to give 3D shape. This gives it a unique specific active site. Ionic, Hydrogen, Di-sulphide bonds and hydrophilic/phobic interactions gives it further support.-2)d The quaternary structure is when one or more different polypeptides are joined together to make a complex molecule. E.g. Haemoglobin has a quaternary structure with a prosthetic group and two alpha and two beta polypeptides. Collagen has three poly-peptides wound around each other forming a rope with cross-links.

3) Collagen and Cellulose4) Three chains of poly-peptides (each poly-peptide is an alpha-peptide with left handed helix) are wound around each other into a helix which is stabilised with lots of hydrogen bonds, which is called a microfibril. Lots of microfibrils are called macrofibrils.5) -haemoglobin has 4 polypeptide groups whereas collagen only has three, -haemoglobin also has a prosthetic group whereas collagen doesnt,-haemoglobin is a transport protein whereas collagen has structural roles,-both have a quaternary structure,-haemoglobin is lobular and soluble, collagen is insoluble and fibrous,6) Alpha glucose is made up of lots of glucose molecules with glycosidic bonds. The bond forms between the OH group on the 2 carbon and the OH group of the forth carbon on another molecule, releasing water. Alpha glucose: the OH group on the second carbon is below it, whereas in beta-glucose its above it.

7) -both are carbohydrates; however starch has amylose molecules whereas cellulose has beta-glucose molecules. Both are insoluble.-cellulose has cross links, starch doesnt.-starch is a branched chain, which means that it is very compact and a storage molecule, whereas the arrangement of macro-fibrils in cellulose make it ideal to have structural roles such as in cell walls, it is embedded in pectin.8) -triglycerides are made up of one glycerol molecule and three fatty acid chains, it can act as an insulating layer of fat or be energy storage,-phospholipids are made up of a glycerol molecule, two fatty acid chains and one phosphate containing groups, which means that the head is hydrophilic and the tails hydrophobic, this makes it ideal to be a barrier, like in the cell membrane-phospholipid bi-layer,-cholesterol are made up of four, they have high energy density and they are used in the phosphor-lipid bi-layer to control fluidity.

9)-catalysts, they increase the rate of reaction/speed processes up, without being used up. They have a specific shape/active site and are globular.

10) Enzymes speed reactions up, without being used up. Biological enzymes are naturally made/found in the body,

11) An enzyme has a uniquely shaped active site which is complimentary to specific substrates. When an enzyme and complimentary substrate collide, it binds to enzyme creating enzyme substrate complex. The enzyme will break it up, the end-products leave the active site. Enzyme is ready to work again.

12) -in the induced fit hypothesis, it states that when substrate enters active site, the shape of active site changes slightly/fits around more snugly also because oppositely charged groups are near each other on enzyme and substrate, This change in shape puts strain on substrate, so its destabilised-reaction occurs more easily. Products have different shape, so dont fit and leave. 13) Ph: if it is too different (too high or too low) to the optimum Ph of the enzyme, it will denature as hydrogen and ionic bonding will be disrupted. Enzyme will unravel.Temp: too high will denature enzyme as hydrogen, ionic, disulphide bonds will vibrate too much and eventually break as they are quite weak.Enzyme conc: If there is an unlimited supply of substrate, the enzyme conc will act as a limiting factor if it runs out-no more active sites available, therefore the reaction cant happen/stops. Vice versa.

14)-competitive inhibitors have a similar shape to that of substrate, they temporarily bind to complimentary active site of enzyme, less enzyme-substrate complexes are made, lower rate of reaction, this is reversible,-non-competitive inhibitors have different shape to substrate but bind to enzyme somewhere other than the active site, which changes the shape of enzyme and active site, which is irreversible, so less enzyme substrate complexes and much lower rate of reaction or maybe no reaction,

15) -coenzymes carry molecules/chemical groups between enzymes if there is more than one stage of reaction in sequence,>co enzymes change in shape during reaction, but are recycled back, they are non-protein,>they might be prosthetic groups, which are permanent parts of an enzyme molecule and speed it up, such as carbonic anhydrase,-some in-organic co-actors (certain ions) can increase the rate of reaction

16a) Metabolic poisons can be competitive inhibitors such as ethylene glycol also known as antifreeze. Ethylene glycol is broken down in the liver by the enzyme alcohol dehydrogenase, which makes a toxic by-product called oxalic acid. By consuming excess amounts of ethanol, it can act as an antidote. It does so by competitively inhibiting the enzyme, which means less toxic by-products are made, but the person might get a serious case of alcohol poisoning, though much less likely to be fatal. (6)

16b)-potassium cyanide non-competitively inhibits an important respiratory enzyme called cytochrome oxidase found in the mitochondria. This means that the person cant respire aerobically and thus lactic acid is build up-which can be very fatal.

17) When an individual is free of disease, has a balanced diet and is of mental, social and economic well-being.

18) -The person might work out, which means that they have a different build/muscle mass to other people,-different bone density,-gender,-age,-person might be pregnant,

19) -the person might be mentally ill and have no social life/reclusive,

20a)-The rabbits would have taken in some of the poison, if the hunters regularly hunted rabbits from that area and eat lots of rabbits, this would mean that the poison would accumulate/build up in the humans and it might affect them after a while.20b)-Biodiversity is the measure of the variety in life/species richness and species evenness. It might be low because the species have an uneven distribution such as lots of rabbits but only two or three foxes.20c)-the rabbits would have eaten some of the poisoned grass/carrots/water., which would have killed some of them. The hunters would further reduce their numbers. This means that the foxes and owls and other predatory animals will be affected and they in turn will reduce in numbers as they will have less food. Even if the hunters didnt hunt the rabbits, the poison would have accumulated in the food-chain, which would have killed the predatory animals. This will disrupt the eco-system and perhaps damage the biodiversity irrevocably,

21) -because plants are the basis of the food chains, they can make energy/food,-vegetarians might not get all the essential amino acids they need,-easier to get protein deficiency,

22) -Plants with desired characteristics are selected, or two different plants with desired characteristics are interbred,-asexual reproduction such as self-pollination, or other methods,-offspring will have desired characteristics,-the whole selection process is done again, this goes on for many generations,

23) -antibiotics will reduce the spread of diseases and infections and increase the yield,-fungicides kill fungus,-fertilisers replenish the soil with nutrients/minerals that the plant needs for growth and repair, which in turn will increase their yield,-pesticides will kill pests that damage the plant,

24) -plasmodium causes malaria, its transmitted by a vector, female anopheles mosquito, mosquito bites,-HIV causes AIDS, through sexual intercourse, sharing of bodily fluids, cuts, blood transfusions,-(mycobacterium Bovis/TB causes TB, droplet infection,

25) -constant region enables it to bind to phagocytes (cell receptor on it),-variable region gives it a unique shape that is complimentary to specific antigen (pathogen),>more than one polypeptide means that agglutination can happen, neutralisation,-hinge region allows a certain degree of flexibility,

26) -Active immunity is usually long-lasting immunity. Passive immunity is acquired by the transfer of antibodies from another thing,-natural immunisation is made in the body, nothing unnatural is introduces e.g. breast milk,-artificial means vaccination or something like that where a harmless strain of the antigen is introduced to start a false primary immune response,

27) If the majority of the people are vaccinated, they will get artificial immunity to the disease, so disease wont spread, will die, as antibodies will kill it, immunological memory will provide long-term immunity to that particular pathogen,

28) -the primary response is much slower, the amount of antibodies made is much lower, in secondary response antibodies will already be there, and increase exponentially in much less time,

29) Explain how biodiversity may be considered at different levels; habitat, species and genetic; (3)-Habitat-environmental variety,-Genetic-individual differences,-Species-genetic differences, DNA structure,

30) Taxonomy: study of the principles of classifications,Phylogeny: study of the evolutionary relationships between organisms,Classification: process of sorting living things into groups based on similarities/differences,. Evolutionary relationships (natural classification), the more closely related they are the more likely to be in the same category,

31a) -common bat has wings and can fly,-dolphins live in water,-platypus lays eggs and has a beak,31b) -DNA/ RNA evidence, enzyme evidence,-the more similar DNA structure the more closely related they are,-cytochrome C-fossil evidence,-behavioural/physical evidence, e.g. platypus breastfeed their youngs so they have mammal characteristics, dolphins have lungs,

31c)It gives a clearer picture as to how simpler organisms evolved and makes it easier to see evolutionary links between species, makes it easier to observe/research/make sense of things. -more convenient, easier to do research on cures,

32) -continuous means there are two extreme values with a range of intermediates, bigger gene-pool, lots of variation, e.g. height in humans,-discontinuous is quantitative, fewer genes, distinct categories, e.g. colours of flowers,

33) Explain and describe the theory of evolution with reference to Darwins four observations. (7)-Complex organisms have evolved from simpler ones, speciation,>offspring appear similar to parents,>no two individuals are identical,>organisms have ability to produce larger number of offspring,>populations in nature tend to remain fairly stable in size,-which suggests that there is selection pressure, the fittest/better adapted individuals survive to reproduce and pass on their genes to offspring, happens over many generation, giving rise to a new species,-allopatric/sympatric speciation,TOTAL: 152