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Why do we eat


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This is for biology students..on the topic WHY DO WE EAT. ? …

This is for biology students..on the topic WHY DO WE EAT. ?

Any one can see it..really its useful and knowledgable for everyone.

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  • Brainstorm 4 main food types and where they come from Fat and protein meat, fish Sugars fruit, sweet things Crbs from pasta, potatoes etc
  • KOH and CuSO4 Biuret Expt H/O whats in our foodtest a variety of foods
  • What happens in times of famine, turn on each other, strong survive Hunt in packs or individually (dogs , spider – what are the benefits of each? Sharing in times of need idea of love and family helps share the bounty – mutualism (communism)
  • What do you notice? Crocodile and shark continue to grow new teeth Why doesn’t it chew for a long time?
  • Much bigger than t rex scales and tail for defence, tend to be herd animals for defence in numbers like african zebra Slow moving not as much energy in the food and plants don’t run away! What if there is a drought? What happens to the carnivores?
  • How does the sheep teeth differ from carnivore? What are the ridges on the elephant tooth for? GRINDING – cellulose is hard to digest due to cell wall so needs to chew for a long time Gap in teeth for rechewing grass, no canine. What about the muscle strength Rabbit teeth continualy grow and are eroded by the hard plant material they eat Why so many molars?
  • Oviraptor Still dependent on plants but will take any opportunity to feed
  • Have survived for millions of years, always plenty of dead things
  • What happens if one factor is missing – plant dies What is the effect on herbivores and carnivores Dinosaur extinction theory, asteroid hits dust and volcanic explosion block out sun for several years… What about the fly trap – tops up its nutrition with protein rich flies! H/O Food chains cut out pics
  • What are the trophic groups in this diagram (all consumers) Assume the little fish feeds on algae then there is a herbivore, series of carnivores and a top predator
  • Important to draw the arrows to indicate direction of food flow
  • Food webs can get very complex EXERCISE – Rose bush food web
  • H/O food chain Qs
  • Name the trophic levels (producer, herbivore, carnivore) Why is it a good idea to eat from the bottom of the pyramid/? Poisons accumulate, energy decreases so need to eat more, don’t need to be as active plants don’t run
  • H/O anticipation guide digestion and absorption H/O vocab square digestion H/O game structure of digestive system Stretch out person until intestine is straight they are 8m long, HORSE 30M! shine torch Ingestion Digestion Absorbtion Egestion
  • Masseter muscle zygomatic arch, cranial ridge = carnivore Herbivore – diastema plate for incisors to press against Epiglotis prevents food going down the wrong way
  • A good way to describe peristalsis is an ocean wave moving through the muscle. These diagrams don’t separate the esophagus from the mouth functions, you might want to talk about what happens in the mouth too.
  • The stomach takes around 4 hours to do it’s job on the food, depending on what kinds of food are digested. Digestive juices HCL and pepsin (protein breakdown)
  • Enzymes breakdown large molecules. Villi look like little fingers Blood system is in close proximity to carry nutrients away around the rest of the body
  • Livers can regenerate missing pieces if necessary. Is one of the largest organs in the body.
  • Explain to students that removing the stones typically means removing the gallbladder, but that the body eventually adjusts to not having the bile stored.
  • Explain the difference between the two types of diabetes. In type 1, the pancreas fails to produce enough insulin. In type 2, the body stops responding properly to the insulin it creates. Enzymes for breakdown of protein, cbh, sugar
  • Depending on the maturity of the group, you can talk about the feces leaving via the anus. Mention the appendix at the bottom of the ascending colon and that it might have been used long ago but is not today Mention the portions of the large intestine, ascending, transverse, descending, sigmoid, and rectum (last one if the audience is mature enough)
  • H/O game word play
  • H/O in teams complete 69 the digestive system then use it to Draw full size body and position organs
  • Why do we need these nutrients from food? H/o match up Plant and animal cell components
  • Anticipation guide microscope Expt view cheek cell, onion cell, hay infusion – scientific drawing practise
  • We burn coal in oxygen to give us energy in powewrstations Factory analogy lorries bring reactants represent blood, factory is mitochondria, co2 h2o are waste products, energy is used for growth, reproduction, movement etc How does body transport blood (oxygen, glucose, co2 etc) pumped via heart H/O Energy in food Expt burn variety of foods
  • Anticipation guide transport in the body lorry need to transport oxygen and food BRAINSTORM PARTS Pump 2 = right side of heart pump blood to oxygen plant (lungs) Return to pump 1 sends blood to factory (rest of body) Heart = pump Vessels like tree branches
  • Video? (major organs H/O) Discuss flow of blood Oxygenated, deoxygenated, 2 pump, left thicker, artery leave heart, veins return, valves Complete heart H/O Dissection of heart Elephant beat 25/min Mouse 600/min Baby 120/min Us 70/min How many beats in a lifetime? Same for mouse? Heart jigsaw in teams EXPT Measure pulse before and after exercise Why does the pulse rate go up? Muscles need more oxygen therefore blood needs to be pumped quicker. Who had lowest rate = fittest ALSO who’s returned to normal quickest.
  • Blood vessels laid out = 100000Km round the earth 2x
  • Exception pulmonary artery Atherosclerosis thickening of artery wall fat deposits hard work for blood to be pumped, finally blocked stroke, heart attack blood flow to heart is blocked and muscle dies SMOKING increase pulse rate (heart beats)15 bpm , Increase blood pressure so heart works harder Increase fats so vessels narrow Increased clotting thick blood harder to move Wbc anaesthetised get more infections PULSE RATE EXPT can feel high pressure in arteries
  • H/O diagram of capillary O2, CO2 and food can pass into/ out of capillaries X =O2 Y= CO2 Z = sugars
  • Exception pulmonary vein Harvey EXPT tie arm drain vein
  • Round the room exercise Blood (5 reading workstations) Blood 50% water, 50% RBC life span 120 days made in bone marrow, rbc like donut, no nucleus 25 trillion Recap H/O circulatory system then provide letter home to Mum H/O
  • Transcript

    • 1. Why do we eat ????
    • 2.
      • Type
      • Carbohydrate
      • Fat
      • Protein
      • Sugars
      • Use
      • Long term energy
      • Protecting organs and long term energy store
      • Making muscle, enzymes, skin, hair
      • Fast energy
    • 3.
      • Food type
      • Protein
      • Sugar
      • Fat
      • Carbohydrate
      • Test
      • Biuret turns purple if protein is present
      • Benedicts turns from blue to red/brown if sugar is present
      • Greaseproof paper gets an oily residue
      • Iodine turns blue/black if starch is present
      Food tests
    • 4.
      • Only eats meat
        • E.g. Spider, lion
      • Its survival is dependent on finding and catching prey
      Top predator – Nothing eats him! Carnivore
    • 5. Carnivore Teeth Adaptation
    • 6.
      • Only eats plants
        • E.g. Cow, aphid
      • Depends on a large supply of plant matter.
      • Longer gut as less energy available in their food.
    • 7. Herbivore Teeth Adaptation
    • 8.
      • Eats a mixture of plants and animals
        • E.g. Pigs, humans
      • Increased chance of survival as they are not restricted to one diet.
    • 9.
      • Breaks down and recycles dead material.
        • E.g. Bacteria, fungi
    • 10.
      • Plants can make their own food using
        • Sunlight
        • Chlorophyll
        • Water
        • Carbon dioxide
      • How are all the consumers and producers linked?
      Primary Producers (Plants)
    • 11.
      • Trophic level
      • Producer
      • Consumer
      – feeding group in food chain (eg Herbivore) – makes own food – eats other organisms for food Definitions
    • 12. Phytoplankton Zooplankton Fish Shark Label the trophic levels as herbivore, carnivore, producer, top predator. Indicate which are consumers. Top Predator Carnivore Herbivore Producer Consumers Food Chain
    • 13.  
    • 14.
      • Food chains describe how organisms gain______ from eating each other in a community.
      • Plants are called _______ because they make glucose using energy from the ______
      • _________ must eat other organisms for their _______ and nutrients.
      Producers Sun Consumers Energy Food Food Chains
    • 15. Only about 10% of energy passed on between trophic levels Few Carnivores More Herbivores All supported by energy from producers Most is lost through the organisms living processes Energy Pyramids
    • 16.
      • Mouth
      • Oesophagus
      • Stomach
      • Small Intestine
      • Liver
      • Large Intestine
      • Gall Bladder
      • Pancreas
      • Rectum
      • Anus
      Let’s find out what happened to your breakfast today! (Breaking food down into smaller pieces) The Digestive System
    • 17.
      • Teeth
      • (mechanical breakdown)
        • Incisors used for cutting
        • Canines used for stabbing and holding
        • Molars large surface area used for grinding
      • Saliva
      • (chemical breakdown)
        • Enzyme (speeds up reactions in the body)
        • Breaks down carbohydrate
    • 18.
      • Approximately 25cm long
      • Moves food from the throat to the stomach
        • Muscle movement called peristalsis
      • If acid from the stomach gets in here that’s heartburn.
    • 19.
      • Stores the food you eat
      • Chemically breaks it down into tiny pieces
      • Mixes food with digestive juices
      • Acid in the stomach kills bacteria
    • 20.
      • Small intestines are roughly 6 metres long.
      • Enzymes and bile are added.
      • Villi increase the surface area to help absorbtion .
      • Nutrients from the food pass into the bloodstream through the small intestine walls.
      Small Intestine
    • 21.
      • Directly affects digestion by producing bile
        • Bile is an enzyme that helps dissolve fat
      • Processes nutrients in the blood, filters out toxins and waste.
      • Is often called the body’s energy factory
    • 22.
      • Stores bile from the liver
      • Delivers bile when food is digested
      • Fatty diets can cause gallstones
      Gall Bladder
    • 23.
      • Produces compounds to digest fats and proteins
      • Neutralizes acids that enter small intestine
      • Regulates blood sugar by producing insulin
    • 24.
      • About 1.5 metres long
      • Accepts what small intestines don’t absorb.
      • Absorbs water and minerals from the waste matter.
      • Absorption means taking into the body via the blood stream.
      Large Intestine
    • 25.
      • Rectum
        • About 15cm long
        • Stores waste before egestion.
      • Anus
        • Muscular ring that controls egestion.
      Rectum and Anus
    • 26. Write the name of each colored organ:
      • Green:
      • Red:
      • Pink:
      • Brown:
      • Purple:
      • Green:
      • Yellow:
    • 27. Answers
      • Green: Oesophagus
      • Red: Stomach
      • Pink: Small Intestine
      • Brown: Large Intestine
      • Purple: Liver
      • Green: Gall Bladder
      • Yellow: Pancreas
    • 28.
      • Cells are the building blocks of life
      • All cells have the following in common:
      • Nucleus
      • Cytoplasm
      • Mitochondria
      • Cell membrane
      • Plant cells also have a cell wall and chloroplasts
    • 29.
      • Nucleus
        • largest organelle
        • control centre
        • Instructions for the whole body
      • Cell membrane
        • Controls the entry and exit of material
      • Cytoplasm
        • Liquid containing cell parts and nutrients
      • Mitochondria
        • Powerhouse (burns energy from food)
      Function of cell organelles
    • 30. ENERGY C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O +
      • Respiration is the conversion of glucose into energy
      • Glucose is “burnt” with oxygen
      • It takes place in the Mitochondria
      Glucose Oxygen ENERGY Carbon Dioxide Water Turning food into energy
    • 31. What is it for ? We need 2 pumps because 1 would not have enough energy to push blood through the lungs and then around the body. Circulatory System
    • 32.
      • Oxygenated blood
        • To the body
      • LHS thicker
      • Deoxygenated blood
        • To the lungs
      Anatomy of the Heart
    • 33. Blood Vessels
    • 34.
      • Oxygenated blood leaving heart
      • High pressure
      • Thick muscular walls
      Structure of Arteries
    • 35.
      • Carry blood to cells
        • Remove waste
        • Deliver oxygen
        • Deliver food
      • Single file r.b.c.
      • Very thin walls (single cell thick)
      Structure of Capillaries
    • 36.
      • Deoxygenated blood returning to heart
      • Thin walls
      • Low pressure
      • Valves – allow flow of blood in one direction
      • Muscle contraction
      Structure of Veins
    • 37.
      • Plasma
        • Liquid carries other components
        • Nutrients
        • Waste like carbon dioxide
      • Red Blood Cells
        • Carry oxygen and carbon dioxide
      • White Blood Cells
        • Fight disease
      • Platelets
        • Clotting
    • 38.