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78 Cards in this Set
- Front
- Back
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Species
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These are organisms that are grouped together based on similarities in characteristics such as appearance, genetics, anatomy, biochemistry and physiology. Species are also capable of producing fertile offspring.
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Habitat
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A place, in which members of a particular species live in, is called their habitat. Most organisms are well adapted to their habitat. Examples of habitats include woodland, ocean floors, forests, towns, swamps etc.
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Biodiversity
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In the world, eco-system or habitat, the amount and variety of species found is biodiversity.
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Random quadrants
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A 50cm or 1m square frame called a quadrant is used to measure sample area size. The numbers of plants in a frame are identified then the abundance is measured using an ACFOR scale.
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Transect
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A long rope or tape measure across a habitat and samples are taken along the rope of the tape.
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Sweep netting
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This will catch any small animals such as insects in a stout net which is swept through vegetation as a person walks through a habitat.
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Collecting from trees
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Small animals fall onto a net when the branch of a tree is hit with a stout stick causing vibrations.
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Pitfall trap
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A small container set in the soil to catch small animals than move through the plants. Should contain water or scrunched up paper to stop the animal crawling out.
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Tulgren funnel
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A jar is placed under a mesh under a light under leaf litter which collects small animals as the animals move downwards as the light dries the leaves
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Light Trap
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An ultra violet light is used to attract and catch flying animals such as moths at night. The light vessel contains alcohol and the attracted animal will fall into it trapping it.
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Species richness
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The different number of species found in a habitat is species richness. The more species the richer the habitat.
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Species evenness:
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The abundance or relative number of an individual in each species is species evenness. Both are used in measuring biodiversity.
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Simpson’s diversity index
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It takes into account both species evenness and richness to measure the diversity of a habitat. Measure using the formula, D is equal to 1 minus the total of little n divided by big n squared. Diversity is 1 minus the total number of individuals of a particular species ÷ individuals of all species squared. High values indicate a diverse habitat; low values suggest habitats dominated by a few species.
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Classification
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Placing living organisms into groups is called classification; biological species with similar characteristics are placed in the same group.
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Taxonomy
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This is the study of differences between species. According to their physical similarities species are grouped together.
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Natural classification
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is the variation between individuals of a species
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Phylogeny
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Is used as the basis for natural classification, as is the study of how closely related different species are, if in the past species shared a common ancestor they may appear closer together on the evolutionary tree.
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The 5 kingdoms
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All living things are placed into kingdoms, of which are 5, Protoctist, Plantae, Animalia, Fungi and Prokaryotes.
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Prokaryotes:
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Belongs to the kingdom prokaryota, includes bacteria. They have no nucleus, naked loop of DNA , no membrane bound organelles for example Golgi, ER etc. have small ribosome’s use mesomes for respiration, smaller than eukaryotes and are free living or parasitic and can cause disease.
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Protoctist
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All members are eukaryotes and contain single celled organisms, contain some multicellular organisms such as algae. They show a variety of forms, free living. They have atrophic or heterotrophic nutrition.
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Fungi
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Has a body of mycelium a network of hyphae strands. A polysaccharide wall called chitin surrounds the cytoplasm, it is multi nucleate. They are mostly free living and saprophytic which means they decay organic matter
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Plantae
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Are autotrophs because they gain their nutrients from the sun (photosynthesis). They are eukaryotes, multi cellular have a cellulose wall and produce multi cellular embryos’ from fertilised eggs.
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Animalia
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Are heterotrophic because they gain nutrients by digesting and absorbing organic matter, are able to move around, they are multi cellular, eukaryotic and can produce blastulas which are balls of cells developed from fertilised eggs
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Carl Linnaeus
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Carl Linnaeus devised the classification system we use now; he studied about 70,000 organisms and according to visible features put them into ranked categories.
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System of classification
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Ranked categories were made called taxonomic groups or taxa to put each organism. There are 8 taxa, Domain, Phylum, Class, Order, Family, Genus, and Species. (Dirty Kinky Priests Come Over For Good Sex). All members show variation but are the same, as you raise though the ranks more and more diversity is obvious. As you descend down to the lower taxonomic groups, placing species accurately becomes difficult. All living things belong to 3 domains. Bacteria (Eubacteria) Archaea (Archeabacteria) and Eukayotae
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Condensation
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Condensation is the linking of biological monomers together to form a polymer; condensation is the removal of a water molecule to form a new covalent bond.
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Hydrolysis
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Hydrolysis is the splitting of larger molecules into small ones, turning a polymer into a monomer. Hydrolysis is the addition of water molecules to break covalent bonds.
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Hydrogen bonds
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Hydrogen bonds come about due to attraction between a slightly negative molecule and a slightly positive hydrogen atom. Hydrogen bonds are weak bongs but are strong in numbers.
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Water
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About 80% of cell content is water. Water has loads of important functions. It is a reactant in chemicals process like photosynthesis and hydrolysis reactions. It is a solvent; some substances are able to dissolve init. It transports substances because it is a liquid and solvent and it helps with temperature control
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Proteins
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Proteins are made from long chains of Amino acids.
Dipeptide: A dipeptide is 2 amino acid chains. Polypeptide: A polypeptide is more than 2 amino chains. Proteins: Proteins are made up of 1 or more polypeptide. |
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Amino acids
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All amino acids have the same structure, a carboxyl group (C O O H), an amino group (NH2) and a variable group (R) attached to a carbon.
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Peptide bonds
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Amino acids are linked together by peptide bonds between C and N to from dipepetides.
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Structure Levels of Proteins
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Proteins have four structural levels. Primary: A sequence of amino acids in the polypeptide chain. Secondary, the polypeptide chain begins to coil into alpha helix or fold into beta pleated sheets. Tertiary, the final 3D structure, the polypeptide chain has coiled or folded even more. It is held together by numerous bonds. The tertiary structure is vital to it structure.
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Bonds in Structure Levels of Proteins
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Primary structures have peptide bonds. Secondary structures have hydrogen bonds. Tertiary structures have Ionic interactions (attracts between positive and negative charges on a molecule, it is weak), disulfide bonds between two molecules of cystine (an amino acid) which has a sulphur atom in each cystine bonds, hydrophobic and hydrophilic interactions and hydrogen bonds
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Fibrous proteins
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Fibrous proteins such as collagen form support tissue in animals, so need to be strong. Fibrous proteins are tough and rope shaped because it is made up three polypeptide chains coiled into a triple helix which are linked by strong covalent bonds. Minerals can bind to the helix to help increase its rigidity.
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Globular proteins
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Globular proteins are round and compact, they are soluble, so can be easily transported in fluids. Haemoglobin is an example of a globular protein. They hydrophobic R-groups are inside the centre f the structure and the hydrophilic are on the outside
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Quaternary structure
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Quaternary structure is a protein that is made up of more than one polypeptide sub unit together, or a polypeptide and an inorganic compound, for example Haemoglobin and Insulin.
*Haemoglobin consists of four polypeptide sub-units. Two alpha chains and two beta chains. |
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Prosthetic group
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A prosthetic group is a group not made of amino acids but is found in proteins and is an essential part of the molecule for example the haem group in haemoglobin.
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Protease
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Protease is an enzyme that catalyses the breaking down of peptide bonds.
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Carbohydrates
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Carbohydrates are very large complex molecules made up of long chains of monosaccharides. Glucose is monosaccharide with 6 carbon atoms in each molecule.
There are two types of glucose alpha which has the H above the hydroxide group and beta glucose which has the H below the hydroxide group. |
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Monosaccharides
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Monosaccharides are joined together by glycosidic bonds, to form disaccharides and polysaccharides. Disaccharides and polysaccharides are formed when two monosaccharide’s are condensed, losing H20 forming a glycosidic bond.
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Maltose
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Maltose is two alpha glucose molecules joined by a glycosidic bond.
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Pentose
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Pentose sugar is 5-carbon monosaccharides.
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Hexose
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Hexose sugars are 6-carbon monosaccharides.
*The most common are hexose sugars which includes glucose and fructose. C6H12O6. Carbohydrate has a general formula if CnH20n. |
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Triose
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Triose sugars are 3-carbon monosaccharides.
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Starch
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Starch is the main energy storage material in plants. Plants store excess glucose as starch. Starch is a mixture of 2 alpha glucose polysaccharides. Amylose which is a ling unchained branch of alpha glucose has a coiled structure, like a cylinder making it compact and so good for storage. Amylopectin is a long branched chain of alpha glucose, has side branches to allow the enzymes which break down molecules to get to the glycosidic bonds easily.
*Starch is insoluble in water, so it is good for storages as water won’t enter the cell through osmosis |
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Glycogen
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Glycogen is the main storage in animals. Excess glucose is stored as glycogen, a polysaccharide of alpha glucose. It is compact and has loads of side branches coming off it.
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Cellulose
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Cellulose is a major component in cell walls in plants; it is a long branched chain of beta- glucose. The cellulose chains are linked to together by hydrogen bonds forming micro fibrils that provide structural support.
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Lipids
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Lipids are a group of chemicals that dissolve in organic substances such as alcohol but are insoluble in water. They include fatty acids, triglycerides and cholesterol.
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Triglycerides
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The product of hydrolysis is triglycerides which is one glycerol and 3 fatty acids. Fatty acid tails are long hydrocarbons which are hydrophobic making them insoluble in water.
Triglycerides are mainly used as energy storage molecules. They have long hydrocarbon tails with lots of energy. They are insoluble in water so they don’t cause water to enter the cell by osmosis; they bundle together as insoluble droplets. |
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Phospholipids
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Phospholipids is the main component in cell membrane, it is made up of one glycerol, 2 fatty acid tails and a hydrophilic phosphate head. The phosphate head is ionised, so attracts water.
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Cholesterol
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Cholesterol is often found in cell membrane, or can be used in the production of steroids. Cholesterol is a hydrocarbon tail with a polar hydroxyl group making it soluble.
Cholesterol strengthens the phospholipid bilayer by interacting with them. The small size and flattened shape allows cholesterol to fit in between phospholipids molecules, causing them to be packed more closely together, making it less fluid and more rigid. |
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Ester bond
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An ester bond is the new bond formed when a condensation reaction takes place, forming a new covalent bond called an ester bond. The ester bond is between the glycerol and fatty acid. Ester bonds are found in triglycerides. Phospholipids also have ester bonds.
Respiration of lipids requires hydrolysis of ester bonds. The glycerol and fatty acid can be broken down into C O 2 and H 2 O releasing energy in the form of ATP |
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Cholesterol
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Cholesterol is four carbons based structured rings joined together, used to form steroid hormones. It is made in the liver by cells. Too much in the bile can cause gallstones and too much in the blood can cause atherosclerosis which is plaque deposits on the lining of the blood vessel, causing circulatory problems.
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Vector
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A vector is a form of transmission.
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Transmission
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Transmission is the way in which a parasitic organism travels from one host to another carrying the disease around.
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Malaria
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Malaria is caused by a eukaryotic organism, the protoctist. The plasmodium parasite causes the disease. The female anopheles mosquito carries the plasmodium from person to person. The anopheles mosquito is a vector; they have fine tube or proboscis mouths that can penetrate the blood vessels. Mode of transmission, female anopheles sucks on blood; the plasmodium develops on the stomach of the mosquito and moves to the mosquitoes salivary gland, and when an uninfected person is bitten the plasmodium migrates to the liver, where it multiples, then once developed it goes into the blood, the uninfected person is not infected with malaria. The gametes of the plasmodium are now in the blood ready to be sucked by the anopheles mosquito where it travels to the stomach joining with zygotes ready to start the cycle again.
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HIV/AIDS
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HIV is a pathogen that causes a virus. The virus enters the body remain, inactive for many years. (HIV Positive) when the virus becomes active it attacks and destroys T-helper cells, weakening the immune system allowing opportunistic infections to be contracted.
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Tuberculosis
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TB is cause by a bacterium. There are two species mycobacterium TB and M.Bovis. TB is usually found in the lungs. TB is spread by droplet infect that is released when a person sneezes, coughs, laughs or even talks. TB can also be contracted from milk or meat of cattle.
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Primary defence:
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Your primary defence is your first line of defence. It protects your body from pathogens entering the body.
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Skin
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Main primary defence. The skin covers the body and is made up of an outer layer called the epidermis which is a layer of cells and has a keratinised layer of dead cells acting as a barrier to pathogens.
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Mucous membrane
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Areas such as the airways, lungs and digestive system are protected by mucous secreting cell called goblet cells. The mucus lines airways trapping tiny pathogens in the air and using ciliated cells move the mucus into the top of the trachea where it can enter the oesophagus where it is swallowed into the digestive system where it is killed by the stomachs acidity of pH 1 to 2 which denatures the pathogens enzymes. Mucous membranes are also found in the gut, anus, nose and ears.
*The eyes are protected by antibodies in the tear fluid. Wax in the ear canals trap pathogens. The vagina is protected by slightly acidic conditions |
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Phagocytes:
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Phagocytes are a secondary defence, if pathogens break through the primary defence. Non specific phagocytes kill pathogens before they reproduce and cause symptoms of a disease. There are two types of phagocytes.
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Neutrophils
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Neutrophils are made in the bone marrow and have a multi lobed nucleus; they travel in the blood and can often squeeze in and out of tissue fluid. They can also be found on epithelial surface, they are short lived but are released in large numbers during an infection.
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Macrophages
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Macrophages are larger than Neutrophils and are also made in the bone marrow. They travel in the blood as monocytes. They are found on body organs particularly lymph nodes, where they develop into macrophages.
*Macrophages play an important role in initiating specific responses to a disease, known as an immune response. |
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Phagocytosis
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Phagocytes work by engulfing and destroying pathogenic cells, when a pathogen enters the cell it is recognises as foreign by antigens. Antibodies then attach to the foreign antigens. Phagocytes have a receptor site which binds to the antibody already attached to the pathogen, enveloping it by folder its membrane inwards. The pathogen is now trapped inside a vacuole called a phagosome which then fuses with lysosome which release enzymes called lysine which digest bacterium/pathogens.
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Antigens
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Antigens are molecules that trigger an immune response. Antigens are large molecules with a specific shape. Foreign antigens stimulate the production of antibodies. Antigens are usually proteins or glycoproteins in or on the plasma membrane.
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Antibodies
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Antibodies are produced in the lymphocytes in the immune system. They are released in response to an infection. They are large proteins with a complementary specific shape that is particular to an antigen. Antibodies are Y-shaped and have a variable region (the arms) and a constant region (the body). It is 4 polypeptide chains held together by disulphide bridges. The constant region enables the antibody to attach to phagocytic cells and helps in the role of Phagocytosis. The variable region which has a specific shape which varies for each antibody due to the different amino acid sequences. The variable group is complementary to the shape of the antigen. Antibodies also have a hinge region to allow a degree of flexibility so it can attach to more than one antigen.
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Cell signalling
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Cell signalling s the communication between cells that allows effective co-ordination of a response.
When a body cell is infected by a pathogen, it is usually damaged in some way. Internal organisms such as lysosomes try to fight the invader. So some pathogen cells are damaged, these parts of the pathogen end up attached to the host plasma membrane which acts as a distress signal which is detected by other cells in the immune system. It also acts as markers to indicate the host cell is infected allowing T-killer cells to recognise the cell is infected and must be destroyed. Next the macrophages partially digest the pathogen then separate out the antigens and incorporate them in to a cell surface molecule which is exposed on the surface of a macrophage which now becomes known as an antigen presenting cells whose function it is, is to find lymphocytes that can neutralise that particular antigen. |
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Immune response
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The immune response is a specific response to the detection of pathogens. It involves B and T lymphocytes. These are white blood cells with very large nucleus and specialised receptors in their plasma membrane. An invading pathogen has antigens which are detected as foreign by B and T lymphocytes. These T and B lymphocytes carry receptor molecules on their membrane. Once the T or B lymphocytes detect the antigen, the immune response can start. Because there are only a few T and B cells in the body, once the correct lymphocyte has been detected it must divide by mitosis a number of times.
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T lymphocytes
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T lymphocytes develop into three types of cells. T helper cells which release cytokines (chemical messenger) that stimulate Phagocytosis. T killer cells which attacks and kills infected body cells and T memory cells. B lymphocytes develop into plasma cells which flow around the blood manufacturing and releasing antibodies and B memory cells which will remain in the body for a number of years and act as the immunological memory. B lymphocytes have antibodies and T lymphocytes have receptors.
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Active immunity
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Expose to an antigen so your body releases its own antibodies, two types, natural when you become immune after catching the disease and artificial when you become immune after you’ve been given a vaccination.
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Passive immunity
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You get given the antibodies made by a different organism. Your body doesn’t produce its own. Natural is when a baby becomes immune due to the mother and artificial, this is when you become immune after being injected with antibodies from someone else. In passive immunity memory cells aren’t produces.
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Nucleic acid
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Nucleic acids come in two forms, D N A and R N A.
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Nucleotides
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Nucleotides are monomers of nucleic acid. Each single nucleotide is 3 subunits. One phosphate group, one organic nitrogenous base and one sugar molecule. The bases are Adenine, Thymine, Guanine, Cytosine and Uracil. DNA has deoxyribose sugar or ribose sugar in RNA. Condensation reaction between phosphate groups of one nucleotide and the sugar of another nucleotide joins the two together.
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DNA
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DNA is a long chain polymer of a polynucleotide. RNA exists in three forms. m RNA which is made up of a strand complementary to 1 strand of DNA, it is a copy of the other DNA (coding strand). r RNA is found in ribose and t RNA carries amino acids to the ribosome’s where they are bonded by polypeptides.
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Enzymes
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The majority of the reactions that occur in living organisms are enzyme-controlled. Without them, the rate of the reactions would be so slow as to cause serious, if not fatal, damage. Without enzymes toxins would soon build up and the supply of respiratory substrate would decrease.
Enzymes are proteins and thus have a specific shape. They are therefore specific in the reactions that they catalyse - one enzyme will react with molecules of one substrate. The site of the reaction occurs in an area on the surface of the protein called the active site. Since the active site for all molecules of one enzyme will be made up of the same arrangement of amino acids, it has a highly specific shape. Generally, there is only one active site on each enzyme molecule and only one type of substrate molecule will fit into it. |
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Test for Proteins
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The reagent used to test for proteins is called biuret reagent. It can be used as two separate solutions of copper sulphate and potassium or sodium hydroxide or as a ready-made biuret solution. In either case, a purple colour indicates a positive result.
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