Biology study


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Biology study

  1. 1. Keith Kiely Biology Study Keith Kiely 2011-2013Nov-11 Page 1
  2. 2. Keith Kiely 1. The Scientific Method 2. Life 3. Food 4. Cell Structure 5. Cell Diversity 6. Osmosis and Diffusion 7. Enzymes 8. Digestive SystemNov-11 Page 2
  3. 3. Keith Kiely 1. The Scientific MethodThe scientific method is the way that the knowledge of the world isfound.The main steps in the scientific method are:  Observation  Hypothesis  Experiment  Conclusion  Relating conclusion to hypothesis  TheoryObservation:This is when you look at something in the world and then you question it.Hypothesis:It makes a guess about your observation. It is an explanation for anobservation.Experiment:This is carried out to see if your hypothesis is true or not. It is the basis ofthe scientific methodConclusion:Is dependent on the result on the experiment that was carried outRelation to Hypothesis:Depending on the original hypothesis made before the experiment(s) theresult might support or reject it.Theory:After the hypothesis is proven right over a number of controlledexperiments, it becomes a theory.Nov-11 Page 3
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  5. 5. Keith KielyScientific Limitations:  Extent of knowledge  Basis of investigation  Ability to read results  Changes in natural world  Accidental discoveries  Experiments  Experiment design  Safety  Control experiments  Sample size  Random selection  Replication Extent of Knowledge: If we knew more about something we can ask more questions Basis of Investigation: If there is a mistake in an investigation, the findings are not valid Ability to Read Results: It can be difficult to read results and compare to original hypothesis Changes in Natural World: The world is changing daily so findings must be revised constantly Accidental Discoveries: Instead of following set rules for findings, they have been found by accident Experiments: For an experiment to be carried out it must be agreed to follow set rulesNov-11 Page 5
  6. 6. Keith Kiely Experiment Design: Each experiment must be designed to look at one factor only so one is being tested Safety: There is only so much things that can be done to keep the area safe. Control Experiments: A controlled experiment can only have one aside from the actual experiment Sample Size: If one simple animal or plant is being tested, the results may be because of the living organism Random Selection: It is better to pick a sample to test completely at random so it’s not biased selection Replication: You could post and publish your results so they can be known and can be replicated.Nov-11 Page 6
  7. 7. Keith Kiely 2. Life What is life?Life is processing all of these five things:  Behaviour  Response  Excretion  Nutrition  OrganisationBRENO= Behaviour, Response, Excretion, Nutrition, OrganismBehaviour:This is where living things and how they react in their surroundingenvironment.Their organs and cells help them react to Sound Smell Touch and TastePlants respond slower than animals and grow towards the light away fromtheir stimuli by photosyntsis.Reproduction:Is the production of a new individual or it is a group of new individuals.Living things are produced by other living things called reproduction.Nov-11 Page 7
  8. 8. Keith KielyExcretion:Is the removal of waste from the body by chemical reactionsNutrition:This is the way that organisms get their food.Plants can make their own food by photosyntsisand are called providersAnimals get their own food so they are consumersNov-11 Page 8
  9. 9. Keith KielyOrganisation:This just means that living this are organised by cells.Cells turn into tissues, tissues to organs, organs to organ system, organsystem toindividual organs and individual organs to populationsCells>>Tissue>>Organs>>Organ System>>Individual Organ>>PopulationMetabolism:This is all the chemical reactions in your body in one organismReactions Include:  Digestion of food  Speed of Repair  Production of New Cells  Production of Energy  Rate of photosyntsis (plants only)Nov-11 Page 9
  10. 10. Keith Kiely 3. Food The Elements of Food: There are 14 important chemical elements in food The four main types are:  Carbohydrates  Lipids  Proteins  Vitamins These are all called biomolecules The six most common elements in food are:  Carbon  Hydrogen  Oxygen  Nitrogen  Phosphorus  Sulphur The five main elements found dissolved in salt are  Sodium  Magnesium  Chlorine  Calcium  Potassium Carbohydrates: The main elements in carbohydrates are  Hydrogen  Carbon  Oxygen The elements are presented as Cx(H2O)y The elements X and Y are always going to be the same while H is always double themNov-11 Page 10
  11. 11. Keith Kiely Types of Carbohydrate: There are three different types of carbohydrates:  Monosaccharides  Disaccharides  Polysaccharides Monosaccharides: This is made up of one sugar molecule Examples would be:  Glucose  Fructose  RiboseNov-11 Page 11
  12. 12. Keith Kiely Disaccharides: This is made up of two monosaccharides. Examples are  Sucrose  Lactose Polysaccharides: This is made up of many monosaccharide molecules. Examples are:  Starch  Cellulose  GlycogenNov-11 Page 12
  13. 13. Keith KielyFunction of CarbohydrateStructural function:Cellulose forms Cell WallMetabolic Functions:Glucose gives energy when we respireGlycogen stores the energy in animalsStarch stores energy in plantsProteinProtein always contains:  Carbon  Hydrogen  OxygenAll of these form to make amino acids.Amino Acids are just building blocks of protein Amino Acids>>Peptides>>Polypeptides>>ProteinsSources of Proteins:  Meat  Fish  Eggs  Peas  BeansFunctions of Proteins:Structural Function:Keratin is found in hair and skin and myosin found in the muscles.Metabolic Functions:Enzymes control the reactions and the antibodies fight infections.Nov-11 Page 13
  14. 14. Keith KielyLipids:Lipids only contain the elements:  Carbon  Hydrogen  OxygenLipids include fat and oilsThe basic unit for a lipid is triglyceride. Each one has one glycerol andthree fatty acidsPhospholipids are fatty substances that a phosphate group replaces fattyacids  Butter  Cream  Milk  Meat  Oils  Fried foodsThese are all rich in lipidsFunctions of Lipids:  Provides energy  Stores energy  Phospholipids form part of cell membraneNov-11 Page 14
  15. 15. Keith Kiely 4. Cell StructureAnimal Cell:  Michcondrian  Nucleus  Cell MembranePlant Cell:  Cell Wall  Chloroplast  Vacuole  Nucleus  Cell MembraneFunctions:Animal:Michcondrian:Provides EnergyNucleus:Brain of CellCell Membrane:Let’s Components in and out of cellNov-11 Page 15
  16. 16. Keith KielyPlant:Cell Wall:Gives plant structureChloroplast:Helps with photosyntsisVacuole:Nov-11 Page 16
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  18. 18. Keith Kiely 5. Cell DiversityTissues:These are a group of cells working together for a similar function.:Plant tissues contain the following:  Dermal Tissues  Vascular Tissues  Ground TissuesDermal Tissues:This surrounds and it encloses the plants. Its location is in the leaf, thestem and the roots. Its shape is rectangular with a tick strong wall with awaterproof surface.The function of the dermal tissue is to protect and to prevent water lossVascular Tissues:This is for transportation; there are two types of vascular tissues.These are:  Xylem  Phloem Xylem: This tissue does not contain nucleus and cytoplasm. Tracheid’s and Vessels are two types of Xylem TissuesNov-11 Page 18
  19. 19. Keith KielyMitosisMitosis is the process by which a cell duplicates its genetic information(DNA), in order to generate two, identical, daughter cells. It is dividedinto 4 stages, Prophase, Metaphase, Anaphase and Telophase. Most cellsdivide by mitosis, these cells are called somatic cells and are generallyinvolved in growth. The other cells, germ cellsdivide by meiosis and areinvolved in reproduction and gamete formation.Mitosis divides genetic information during cell division.Preperation  The chromatin replicates itself  The cell builds up a large store of energy  Organelles either replicate or are madeProphase  First the chromatin condense to form chromosomes.  They then double to form sister chromatids  The membrane disappears and the centrioles separate and grow spindle fibresMetaphase  The centrioles move to the poles and attach to the spindle fibres to the centromere, which is the point where the sister chromatids are joined together.Anaphase  The centromere splits  The chromatids separate and are drawn to opposing polesTelophase  The centriole duplicates  The nuclear membrane reforms  The spindle breaksdown  The cytoplasm divides in two In plant cells a cell plate grows in the middle, and a cell wall is produced on either side.There are now two daughter cells, both of which are identicle to the original parentcell.Nov-11 Page 19
  20. 20. Keith Kiely 6. Osmosis and Diffusion Diffusion: Diffusion is the movement of the molecules from a region of high concentration to a region of low water concentration. It is a passive process; this means that it will not need an external force of energy Examples of diffusion:  Smell of Perfume  Bread Making  Stink Bombs  OxygenOsmosis:Osmosis is the movement of water molecules from a region of low concentration to aregion of high concentration.Diffusion and Osmosis Compared:  Both diffusion and osmosis involve in the moving of molicules from high to low concentrations, this means it is passive.  The difference between the two is that osmosis requires a semi-permuable membrane and diffusion does not.Semi-permeable Membranes:Semi-permeable membranes let some molecules in and out of the cell and trap somemolecules into the cell.Some of the molecules at can pass through it is:  Water  Oxygen  Carbon dioxideSome of the molecules that can’t easily pass are:  Salt  Sugars  ProteinsPlant Cells in Concentrated Area:  Cytoplasm has salt, starch, sugars and proteins dissolved in water  If plant cell is left in distilled water in becomes less concentrated.  Water passes through vacuole and becomes swelled, cell is a lot stronger.  This is because of turgor pressure.  This can be compared to air forced into a tyreNov-11 Page 20
  21. 21. Keith KielyTurgor pressure is the pressure of the vacuole and cytoplasm against the cell wallAnimal Cells in Concentrated Area  If an animal cell like the red blood cells are placed in a dilute solution, water will enter with osmosis  The cells will expand and might burst because animal cells do not have a cell wallOsmosis and Food Preserving:Placing food with bacteria or fungi in it in a very concentrated solution will make itlose water by osmosis; this prevents the bacteria or fungi from growing and stops foodfrom decaying.Nov-11 Page 21
  22. 22. Keith Kiely 7. EnzymesFeatures of Enzymes:An enzyme is a protein that spends up chemical reactions without being changed itselfMetabolism is the the sum of all chemical reactions taking place in an organismMetabolism includes: Reactions in which complex molecules are broken down. It is also known as Catabolic Reactions. Reactions on which complex molecules are formed. Also known as Anabolic Reactions.Energy Sources:  The sun gives the original form of energy for all living things. In photosyntsis the suns energy is converted into chemical energy in biomolecules such as glucose  Cellular energy from chemical bonds. This is released through respiration and used by living things to allow metabolismFeatures of Enzyme Action:  The molecule that an enzyme reacts with is a substrate  The molecules produced my an enzyme is the product  Enzymes work because they have the correct shape to attach to the substrate  Enzymes are specific. That means that the active site allows each enzyme to join with one substrate  Enzyme reactions are reversible. This means they can join molecules to form a bigger one or break down to form smaller onesNov-11 Page 22
  23. 23. Keith KielyFactors Affecting Enzymes:There are two Factors affecting enzyme action:  Temperature  pHTemperature:  At 0˚C water freezes to ice. This means that enzyme and substrate molecules can’t move. Enzyme action is zero at this point.  As temperatures increase, enzyme activity is faster. This causes them to collide more often  Human enzymes change their shape when it comes to 37˚C. above this temperature reactions will fall  As the temperatures get higher, enzymes become less useful and die. This is called denaturedpH:The pH scale runs in-between 0 to 14. 0 to 6 are acids, 7 are neutral and 8 to 14 arebasics.  Most enzymes work best at a pH close to 7 (7-9)  At higher or lower pH values the active site becomes altered  Enzymes can be denatured by unsuitable pH levels  Pepsin is an enzyme that is adapted to work in the stomach at a pH of 2Nov-11 Page 23
  24. 24. Keith KielyImmobilised Enzymes:Bioprocessing is the use is the use of enzyme controlled reactions to make a producer.Immobilised enzymes are attached to each other or to an inert substanceBenefits:  They are as efficient as isolated enzymes or sometimes more  The product contains no enzyme so saves on separation costs  The enzymes that are very expensive can be used over and overUses:  Glucose is often used for sweeteners in drinks  Penicillin is an antibiotic used to control bacterial growth  Enzymes can be immobilised on paper or plastic and used to find certain substancesNov-11 Page 24
  25. 25. Keith Kiely 8. Human Nutrition and Digestive SystemTypes of Nutrition:Nutrition is the way which organisms gets and uses their food, the two types ofnutrition is:  Autotrophic  HeterotrophicAutotrophic:This type is when organisms can make their own foods. Examples would be, plants,seaweeds and some bacteriaHeterotrophic:This is when organisms get their food from the surrounding environment. Exampleswould be, Animals, fungi, amoeba and some bacteriaThere is three types of heterotrophic nutrition:  Herbivores  Carnivores  OmnivoresHerbivores:These are animals that feed only on plants. Examples would be, cattle, sheep andrabbits.Carnivores:These are animals that feed on other animals. Examples would be, dogs and catsOmnivores:These are animals that feed on animals and plants. Examples would be, humans andbadgersEvents in Human Nutrition:  Ingestion  Digestion  Absorption  EgestionNov-11 Page 25
  26. 26. Keith KielyIngestion:Physical intake of food into the mouthDigestion:The physical and chemical breakdown of food. It is to allow small molecules of thefood to be absorbed in the small intestineAbsorption:This happens when food passes through the small intestine and into the bloodEgestion:This is when all the unabsorbed food passes through the anusThe Digestive System: ~~~~~~~~~~~~~~~~~~~~~~~~The Mouth:Physical Digestion is taken place in the mouth by the teeth. There is four types ofteeth, their names are:  Incisors  Canines  Molars  Pre-MolarsIncisors:These are the four front teeth and used for cutting and slicing the foodCanines:These are the two teeth, one either side of the Incisors and they are used for tearingfoodMolars/Pre-Molars:These are all the back teeth and all are used for grinding and chewing the foodChemical Digestion:This is carried out in the mouth by the enzyme called amylase found in the saliva. ThepH in the mouth is between 7-8 which is the optimum pH for amylase to work on.Amylase also digests starch to maltoseNov-11 Page 26
  27. 27. Keith Kiely 9. PhotosynthesisIntroduction:Photosyntsis is the process of how plants make their own food. The sun gives light tothe plant and it combines with carbon dioxide and water to form glucose and oxygen.Chlorophyll is used as catalysts in this processThe equation for Photosyntsis is:6CO2 + 6H2O>>>chlorphyll+light>>>C6H12 + 6O2Role: Makes its own food Makes food for animals (when eaten) Forms oxygen for plants and animals Formed fossil fuelsLocation:Sources of Light, CO2 and Water:The Light Stage:The Dark Stage:Nov-11 Page 27