Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Biology 1.5 “Mammals as Consumers” Bio1.5 Life processes related to a mammal as a consumer Part One: Processing Food (physical and chemical digestion, absorption, assimilation, egestion) Here we begin our journey along the alimentary canal¹ from mouth to anus The Buccal Cavity (mouth + teeth) ¹ aka: digestive system, gut Tooth Types • Incisors – biting & cutting food • Canines – tearing meat – piercing & holding prey • Premolars – chewing, grinding soft food • Molars – chewing, grinding hard food Pre Molar or Molar? Premolars: Bicuspid (two cusps) Molars: Quadrate (humans, some other spp) Four cusps are arranged in a rectangle; there may be a fifth. Hypsodont: There is a lot of enamel and dentine above the gumline and the top of the pulp. This kind of molar is found in mammals that wear their teeth a lot, eg horse. Parts of a Tooth cement Functions of Tooth Parts • Enamel – covers crown, hardest substance in body, made of calcium phosphate • Dentine – underneath enamel, harder than bone • Pulp cavity – nerves & blood vessels run through this • Cement – covers root, holds tooth in jaw • Crown – part of tooth above gum • Root – part of tooth in jaw (molars have more roots than incisors) How Many Teeth Do You Have? • In humans, the first set (20 milk teeth) appear from age six months to two and a half years. The permanent dentition replaces these from the sixth year onwards, the wisdom teeth (third molars) sometimes not appearing until the age of 25 or 30. • Adults have 32 teeth: two incisors, one canine (eye tooth), two premolars, and three molars on each side of each jaw. Dental Formula “method of recording number and types of teeth in mammal jaws” Lower Jaw Upper Jaw Upper Lower i2 2 c 1 pm 2 1 2 m3 3 x2 = 16 x2 = 16 total = 32 Animal Dental Formula Example Dental Formulae Carnivores • Cat 3.1.3.1 3.1.2.1 • Dog 3.1.4.2 3.1.4.3 Omnivores • Pig 3.1.4.3 3.1.4.3 • Human 2.1.2.3 2.1.2.3 Herbivores • Cow 0.0.3.3 4.0.3.3 • Horse 3.1.3/4.3 3.1.3.3 • Rabbit 2.0.3.3 1.0.2.3 • Sheep 0.0.3.3 3.0.3.3 Herbivore Teeth - Sheep • Sharp lower incisors – Cutting grass • Bony pad – For incisors to cut against • Gap – diastema – Clear food, protrude tongue to grasp grass • Molars – Grinding plant material Diastema • + eyes face forward – Watch for predators Carnivore Teeth - Dog • Sharp incisors – Biting meat • Long pointy canines – Piercing, holding, tearing prey • Teeth right along jaw – Chewing meat • Overlapping teeth – “Scissor like” to chop meat • Jagged molars – Cutting & grinding meat • + eyes face front – Focus on prey *Root Canal • (endodontic treatment) -- procedure in which the diseased nerve (also called the pulp or inside core) of a heavily decayed or damaged tooth is removed and the central pulp space of the tooth is filled and sealed with dental cement. http://www.ahealthyme.com/topic/dentalterms *Knocked out teeth • Avulsion: injury in which a body structure is forcibly detached • What do you do? See: http://www.nlm.nih.gov/medlineplus/ency/a rticle/000058.htm *Shark teeth • Sit in scissor like rows • Next tooth always ready to erupt • 1000s shed over lifetime (some species lose 35,000!) F Pharynx A Tongue G Larynx H Oesophagus B Liver C Gall Bladder D Large Intestine (colon) Rectum Stomach I E J Pancreas K Small intestine (ileum) L Anus Digestion “The breakdown of food into molecules small enough to be absorbed into the blood” • Physical Digestion: Mechanical breakdown of food – chewing (mastication), churning of food by stomach. • Chemical Digestion: Enzymes + bile chemically break food down. What are physical and chemical digestion and why are both needed for the efficient digestion of food? • Physical digestion occurs when food is broken down into smaller pieces by the teeth or the muscle action of the stomach wall. • Chemical digestion is similar in that it results in food being broken down into smaller pieces, but is different in that it involves the use of enzymes to break the chemical bonds holding the food molecules together. • Both types of digestion are required because physical digestion breaks up the larger pieces of food first, thus increasing the surface area available for the enzymes in chemical digestion to work on. This increases the overall efficiency of the digestive process. Mouth • Digestion starts here: food taken in: ingestion • Food chewed into smaller pieces (physical digestion) • Saliva moistens and lubricates the food making it easier to swallow • Saliva contains salivary amylase (an enzyme) which chemically breaks starch down to glucose* (chemical digestion) • Salivary amylase is made by salivary glands, works at a pH of 7 and is a carbohydrase type of enzyme • Tongue forms food into a ball shaped “bolus” and is swallowed * Actually maltose (which is converted to glucose in the epithelium of the villi in the small intestine) Oesophagus • Food pushed to stomach by wave of muscular contraction behind the food this is called peristalsis (7s for food to get from mouth to stomach) Oesophageal Peristalsis http://www.nature.com/gimo/contents/pt1/fig_tab/gimo13_V1. Oesophagus – Barrett’s Syndrome Stomach • Large muscular bag, churns and mixes food. Food becomes a soupy mix called chyme, Food stored for ~4 hours • Acid (HCl) activates pepsin a protease enzyme (enzymes that break protein down to amino acids), produced by stomach wall, work best at pH of 2 • Acid in stomach kills bacteria in food. • Water, alcohol and some food absorbed into blood here • Gastric Juice: A thin, virtually colourless acidic fluid secreted by the stomach glands and active in promoting digestion (pepsin + HCl) ! Churning = physical digestion ! Pepsin action = chemical digestion *Why doesn’t your stomach digest itself? • Mucous stops the stomach digesting itself • Pepsin secreted as pepsinogen from stomach wall (inactive) only active when it touches the stomach acid. *Haggis • Made of sheep's or calf's heart, lungs, liver minced with oatmeal onions and boiled in the animal's stomach *Stomach Gurgles aka borborygmi http://www.youtube.com/watch?v=VgoZbf6Jm5M&featu Causes: 1 In stomach / upper small intestine as muscles contract to move food and gastric / digestive juices along (normal!) – Intestinal housecleaning? – Happens most several hours after eating – this is why stomach growling is associated with hunger. 2 Can also happen when incomplete digestion of food causes gas (eg in lactose intolerance, coeliac disease (gluten)) 3 Caused by disease … include carcinoid neoplasm and celiac sprue. http://en.wikipedia.org/wiki/Kuru_%28disease%29 Small Intestine - Ileum • Bile is added (breaks down fat, neutralises stomach acid so other enzymes can work also gives faeces their brown colour) • Pancreatic enzymes added (break down proteins, carbohydrates) • Soluble food passes across small intestine wall into blood: absorption • Villi (finger-like projections increase surface area for absorption) • Surrounded by rings of muscle which ensure peristalsis continues, forcing food along • 7 metres long, 2.5-3 cm wide Villi Structure ~ 1mm long Thin surface layer (epithelium) – food absorbed quickly Dense network of blood capillaries – to absorb food quickly (and transport to body cells) Fatty acids & glycerol may reform to fats in the intestine lining, these may be absorbed by the lacteal pass to the ‘lymphatic system’ and eventually end up in blood. Main Function • Villi (and micro villi) increase small intestine surface area – This improves effectiveness of nutrient absorption into capillaries Video Clips • Small Intestine Endoscopy: http://www.youtube.com/watch?v=Ln09qihUi3g • Worm in Small Intestine: http://www.youtube.com/watch?v=EXuoOWb8b Gg • Tapeworm Segment: http://www.youtube.com/watch?v=3uk_aCZxmW Y&feature=related • Roundworm in cat intestine http://www.youtube.com/watch?v=dB0cL3PcYZI &feature=related Peristalsis in horse intestine Villi *Extra Guts For Experts Small Intestine Size and Area • The small intestine in an adult human measures on average about 5 metres (16 feet), with a normal range of 3 - 7 metres; it can measure around 50% longer at autopsy because of muscle relaxation after death. It is approximately 2.5-3 cm in diameter. • CALCULATE THE AREA (use 5m & 2.75cm) Area = circumference x length = pi x d x l = 3.141 x 2.75 x 500 = 4319cm2 = 0.43m2 (3.141 x 0.0275m x 5m) Actual small intestine area… • Although as a simple tube the length and diameter of the small intestine would have a surface area of only about 0.5m2 or 50cm2, the surface complexity of the inner lining of the small intestine increase its surface area by a factor of 500 to approximately 200m2, or roughly the size of a tennis court. Small Intestine Parts Parts of Small Intestine • Duodenum 26 cm long. Breakdown of food, using enzymes. • Jejunum 2.5 m. Absorption of food • Ileum 3.5 m. Absorb vitamin B12 and bile salts and whatever products of digestion were not absorbed by the jejunum. * Cystic Fibrosis • Inherited genetic disease – symptoms include excess mucous production in lungs, gut • Prevents pancreatic enzymes reaching small intestine. • SOLUTION? – Coughing (lungs) – Oral enzymes (gut) • SOURCE? – Pigs • more issues… Pancreas • Produces pancreatic juice which contains enzymes that breakdown carbohydrates, fat, proteins. These are secreted into the duodenum part of the small intestine where they have their action • Pancreatic juice includes: • • • Lipases (break down fat to fatty acids and glycerol – this is possible because bile has already emulsified the fat and raised pH to a level where lipase can work. Amylase (breaks starch down to glucose) Protease (breaks protein down to amino acids) • Pancreatic duct: tube connecting pancreas to duodenum • Also: produces hormones such as insulin which controls blood sugar levels. Sweetbreads (on mushroom risotto) Sweetbreads also = thymus, testis… Gall Bladder • Stores the bile made in the liver (max = 50mL) • Bile leaves via bile duct and enters small intestine at the duodenum What does bile do? – Bile is the only non enzyme involved in chemical digestion – Bile is an alkaline solution, it raises pH of chyme leaving stomach to ph of 8 in the small intestine • Pancreatic juice contains the enzymes lipase, amlyase, protease – these work best at a pH of 8 – Bile contains salts which emulsify fats • Emulsification: break down into small droplets • This increases surface area so that: – Lipases work more effectively to break fat into fatty acids and glycerol AND THEREFORE: – Rate of absorption in small intestine will be faster Basic Emulsion Experiment 1 Fill a clean, empty bottle with water. 2 Add some oil to the bottle of water and screw the lid firmly in place. Shake the bottle vigorously so that the oil and water form a cloudy mixture. 3 Leave the bottle to stand for a while. Observe how the oil separates from the water and floats to the surface. 4 Add a few drops of dish soap to the bottle. Shake it up again. 5 Leave the bottle to stand for a while. Notice that the oil and water no longer separate but remain mixed. The oil has broken up into droplets that are held in the water by the emulsifying action of the soap. Video: Science Experiment How Bile Emulsifies Fat http://www.youtube.com/watch?v=VQrtYap84zA&feature=player_detailpage What does Bile do? Do This: • Mix a little oil + vinegar in a test tube. Observe. • Add a small pinch of mustard, mix. Observe. Results Copy title then copy & complete below: 1. Oil and vinegar d_______ mix 2. The mustard emulsified the oil (this means it spread the o____ through the v_____) 3. Bile e_____ oil and fat in the s____ i_________. This helps d_________ by breaking lipids like f__ and o____ into smaller pieces so that the enzyme l______ can work more effectively as it has more s_______ a_____ to work on. !Why does the gut have different regions / sections? • Why not just have one big sack where everything is digested in the one place? Large Intestine - Colon • Water & minerals absorbed, pass into blood • Surrounded by rings of muscle which ensure peristalsis continues, forcing remaining insoluble food to rectum • 1.5 metres long, 6 cm wide From Greys Anatomy pub. 1918 Appendix • No CLEAR function in humans • BUT some suggestion that the appendix may harbour and protect bacteria that are beneficial in the function of the large intestine • In some herbivores bacteria in the appendix break down cellulose • About 10cm long 7-8mm wide Appendix Rectum • Temporary storage for faeces. • When full the nervous system triggers need to defecate. Anus • Function: expelling faeces (egestion or defecation) Liver • Assimilation: Food molecules packaged & stored for use in cells (energy, growth, repair) • Produces bile (helps breaks down fat & is stored in gall bladder) • Breaks down toxins (eg alcohol) ! The only internal human organ capable of natural regeneration of lost tissue; as little as 25% of a liver can regenerate into a whole liver *How long does it take for a damaged liver to repair itself? • The liver is a unique organ. It is the only organ in the body that is able to regenerate... that is completely repair the damage. With most organs, such as the heart, the damaged tissue is replaced with scar, like on the skin. The liver, however, is able to replace damaged tissue with new cells. An extreme example is a patient who suffers an overdose from Tylenol. In this example up to 50 - 60 percent of the liver cells may be killed within 3 - 4 days. However, if no other complications arise, the patient's liver will repair completely, and a liver biopsy after 30 days will appear completely normal with no signs of damage and no scar. However, the long-term complications of liver disease occur when regeneration is either incomplete or prevented by progressive development of scar tissue within the liver. This occurs when the damaging agent such as a virus, a drug, alcohol, etc., continues to attack the liver and prevents complete regeneration. Once scar tissue has developed it is very difficult to reverse that process. Severe scarring of the liver is the condition known as cirrhosis. The development of cirrhosis indicates late stage liver disease and is usually followed by the onset of complications. A liver riddled with multiple secondary cancer deposits Digestion Terms Summary What Where How Ingestion Mouth Food taken into body Digestion Gut Absorption Stomach (a little), Small Intestine (most) Food broken into pieces small enough to be absorbed into the blood Food molecules cross gut wall into the blood for transportation to body cells (via circulatory system) Assimilation Liver Food molecules enter cells and are used for energy, growth, repair Egestion Undigested food (+ bacteria) leaves the body as faeces Anus Enzymes • • • • • are chemicals are protein are not living don’t eat speed up chemical reactions (eg digestion by breaking chemical bonds between molecules) They don’t look like this They look like this Pepsin Visual Summary of Enzyme Action Tabular Summary of Enzyme Action Group of enzyme Carbohydrases Proteases Lipases Proteases Example Site of production Substrate Products Optimum pH Amylase Salivary Gland / Pancreas Starch Glucose 7 Stomach Wall Protein Pancreas Lipids Glycerol + Fatty Acids 8 Pancreas Proteins Amino Acids 8 Pepsin Lipase Trypsin + Chymotry psin (*or maltose, later converted to glucose) Amino acids 2 (*actually peptides which are later digested to amino acids by trypsin) * What does xenical do? * Read: http://biology.about.com/library/organs/bldigestpan2.htm Enzymes and optimum pH pH affects how different enzymes function, each digestive enzyme has an optimum pH that it works best at. Outside of this their effectiveness is less. At extreme pH their 3D shape is changed (denaturated) and they can no longer bind to food particles and break them up • explain how pH affects the functioning of an enzyme • elaborate upon why different foods are digested in different parts of the gut. Enzymes are not alive therefore they can’t be killed Enzymes and their location • Because enzymes have different optimum pHs they must be located in separate regions of the gut therefore the food they digest is also digested in different locations – Eg salivary amylase digest starch to glucose in the mouth (optimum pH:7 which matches the neutral pH of the mouth). Amylase is denatured in stomach acid this is a pH of 2 which is the optimum pH for pepsin to digest protein. *Kiwifruit vs Agar Task: Place a slice of kiwifruit on some agar. Leave it for 10min. Observe. Copy & Complete: Kiwifruit vs Agar Observations before: Observations after: Inferences: A method to test our inferences: *Q: Why Won’t Pineapple and JellO Be Friends? • A: If Jell-O™ ads and 1950s cookbooks are to be believed, you can mix almost anything with gelatin and have it come out tasty. Ham? Absolutely. Carrots? Sure thing. Tomato soup? M’m, m’m, good. • The only ingredient that seems to be taboo is the one that actually sounds delicious: fresh pineapple. Unfortunately, the tropical treat works like kryptonite on Jell-O because it contains an enzyme called bromelain, which prevents gelatin from forming into a solid. But fret not, fruit salad and mold fans: canned pineapple doesn’t contain bromelain. The canning process heats the pineapple to a temperature sufficient to break the enzyme down, making it oh-so Jell-O friendly. Source: http://blogcritics.org/tastes/article/q-why-wont-pineapple-and-jell/ So, what’s Bromelain??? http://en.wikipedia.org/wiki/Bromelain Digesting Starch Experiment • Did salivary amylase break down the starch to glucose? • What was the evidence? • How do we know the saliva didn’t contain glucose? • Why did we leave the tube for 20min? Comparing Guts of Different Consumers Herbivores Koala Goat Carnivores Vampire bat Wolf Omnivore - Pig Herbivore Gut Features • • • • • • • (not including features of teeth) Salivary carbohydrate enzymes – begins chemical digestion in mouth (head start required to get max nutrients out of low nutrient diet) Extensive chewing – breaks open tough plant cells & increase surface area of food to aid chemical digestion (both to get max nutrients out of low nutrient diet). May rechew (cud in cows) Weak stomach acid – diet low in protein (don’t need to activate much pepsin) Large stomach – to hold max amount of low nutrient food. Slow gut transit time – to allow for maximum time to digest difficult to digest food & absorb all nutrients in the low nutrient food Long Small intestine – large surface area to absorb max nutrients out of low nutrient food (and allow max chance of full chemical digestion) Long large intestine - Use bacteria to breakdown indigestible fibre in the large intestine Specialised Herbivores Humans can’t digest cellulose (sugar in plant cell walls = fibre) as lack enzyme cellulase. Herbivores lack cellulase too BUT may have bacteria in their gut which have cellulase. The bacteria break cellulose down to glucose using some for themselves the remainder can be used by the herbivore. Hindgut Digestion/Fermentation eg rabbit, horse, rhino, rodents Bacteria found in caecum / appendix – this is AFTER the small intestine (where absorption occurs) so rabbits will have to eat their faeces in order to get the glucose provided by the bacteria (they may eat faeces anyway to allow for more digestion / absorption of http://www.youtube.com/watch?v=maWXVKI-gq4 nutrients). Copraphagy = eating faeces http://www.merricks.com/digestion.html#lgintest http://www.youtube.com/watch?v=8lqk7igz9L4&feature=related Foregut Digestion/Fermentation aka ruminant eg cow, sheep, goat Simple Version: Cellulose digesting bacteria found in a four chambered stomach. These break down cellulose to glucose which is absorbed in the small intestine. Even with these bacteria cellulose is difficult to digest and a long small intestine is necessary. * More detail Food softened in first two stomach compartments (by bacterial action). Bacteria break down cellulose to glucose (absorbed in small intestine) Regurgitates this food (cud), rechews to further break down plant matter and stimulate digestion (ruminating).In third compartment water and minerals are absorbed. In fourth food is digested in a similar way to in humans ** Even more detail The four parts of the stomach are rumen, reticulum, omasum, and abomasum. In the first two chambers, the rumen and the reticulum, the food is mixed with saliva and separates into layers of solid and liquid material. Solids clump together to form the cud or bolus. The cud is then regurgitated, chewed slowly to completely mix it with saliva and to break down the particle size. Fibre, especially cellulose and hemi-cellulose, is primarily broken down into volatile fatty acids in these chambers by microbes (Cellulomonas spp.). Protein and some other carbohydrates are also fermented. Even though the rumen and reticulum have different names they represent the same functional space as food can move back and forth between them. Together these chambers are called the reticulorumen. The degraded digesta, which is now in the lower liquid part of the reticulorumen, then passes into the next chamber, the omasum, where water and many of the inorganic mineral elements are absorbed into the blood stream. After this the food is moved to the true stomach, the abomasum. The abomasum is the direct equivalent of the stomach in humans, and food is digested here in much the same way. Want MORE detail? Go to: http://en.wikipedia.org/wiki/Ruminant * Extra For Experts • Compare the efficacy of hindgut and foregut digesters http://en.wikipedia.org/wiki/Hindgut_fermentation • Compare the caecal and faecal pellets of rabbits http://en.wikipedia.org/wiki/Rabbit#Diet_and_eating_habits Carnivore Gut Features (not including features of teeth) • Strong stomach acid – to activate pepsin (to digest meat) • No extensive chewing – meat easy to digest (chewing not needed to increase food surface area, swallow in bulk allows you to compete with other carnivores for max food) • Small stomach – but rapidly expands to engorge food (carnivores may irregularly get food) • Short small intestine – meat nutrient rich (only a short small intestine is needed to absorb the nutrients required) • Short large intestine (colon) - No further digestion / absorption of food (also lack cellulose digesting bacteria here) • Fast transit time – meat nutrient rich, easy to digest (long time not required to digest and absorb meat) Omnivore Features The human system is closer to that of a primate, who has a slightly longer large intestine and shorter small intestine. But both share attributes of both systems: • • • • Salivary enzymes (to start digesting carbs) herbivore trait. Strong stomach acid (to digest meat), carnivore trait. Short large intestine carnivore trait. Fast transit time carnivore trait. Bio1.5 Life processes related to a mammal as a consumer Part Two: Circulation (transport of products of digestion within the body) Circulation System Notes • Organ system consisting of heart (pump), vessels (veins, arteries, arterioles, capillaries) • Transports: – Oxygen (from lungs) to the cells that need it for respiration (to produce energy) – Glucose (from small intestine) to the cells that need it for respiration (to produce energy) – Other molecules (food, hormones) that have been packaged by the liver – Wastes such as carbon dioxide to the lungs for exhalation *Basic Circulation Plan *Detailed Circulation Plan *Heart Exterior http://wikieducator.org/The_Anatomy_and_Physiology_of_Animals/Heart_Worksheet *Heart Interior *Heart Interior (v2) *Components of Blood Red Blood Cells • Disc shaped, no nucleus • Haemoglobin pigment binds to oxygen weakly (oxygen released in tissue where oxygen is low) • Life span: 4 months (dies, broken down, iron stored in liver) • Made in bone marrow (ribs / breast bone) White Blood Cells • Also called leucocytes • Some engulf / eat / destroy bacteria at infection sites or in blood • Other produce antibody to inactivate pathogens • Made in red marrow of bones Platelets • Help clot blood to stop bleeding at wounds • Made when pieces of cytoplasm bud off larger cells Plasma • Liquid part of blood, straw coloured • Carries dissolved substances (salts, + products of digestion: amino acids, glucose, + wastes (urea, CO2) + hormones (eg adrenalin) • Carries plasma proteins (for clotting), antibodies (for protection against pathogens) Blood Loss* Four classes: • Class I Hemorrhage involves up to 15% of blood volume. There is typically no change in vital signs. • Class II Hemorrhage involves 15-30% of total blood volume. A patient is often tachycardic (rapid heart beat). The body attempts to compensate with peripheral vasoconstriction. Skin may start to look pale and be cool to the touch. The patient may exhibit slight changes in behaviour. Saline solution is all that is typically required. Blood transfusion is not typically required. ABL about here (33%). ABL = allowable blood loss • Class III Hemorrhage involves loss of 30-40% of circulating blood volume. The patient's blood pressure drops, the heart rate increases, shock, capillary refill worsens, and the mental status worsens. Saline solution and blood transfusion are usually necessary. • Class IV Hemorrhage involves loss of >40% of circulating blood volume. The limit of the body's compensation is reached and aggressive resuscitation is required to prevent death. Blood* • How much & how much can I lose? – Allowable blood loss calculator^ (amount you can lose before you need a transfusion) and estimate of total volume: http://www.manuelsweb.com/blood_loss.htm • NB: The hematocrit (Ht or HCT) or packed cell volume (PCV) or erythrocyte volume fraction (EVF) is the volume percentage (%) of red blood cells in blood. It is normally about 45% for men and 40% for women. • ^ who would need to know this? Why? Bio1.5 Life processes related to a mammal as a consumer Part Three: Respiration (use of food at the cell level) From Ass. Specification: Structure includes lungs but structures in lungs not needed… Respiratory System • Organ system (lungs etc) that its function is – exchanging gases with the environment OR – to get oxygen into the body and remove carbon dioxide. – NOT: breathing (not enough detail) – NOR using O2 to release energy from food (that’s respiration) Remember….! • Respiration is NOT breathing • Breathing is inhalation/exhalation of air • Gas exchange diffuses oxygen into the blood and carbon dioxide out of the blood • Circulation delivers oxygen and glucose to the cells (for cell respiration) and takes carbon dioxide away (EASIER) Respiration (ATP!) (ATP!) (nb: respiratory enzymes speed up the process of respiration) What is so important about ATP? • The ATP molecules provide the energy needed for all other cellular processes. • This energy is essential as it is used to join small molecules together to make larger ones (metabolism). It enables muscle cells to contract so that mammals can move. It is necessary for the active transport of chemicals. If these processes were not to happen the animal would not survive, as it would be unable to move, feed, grow or repair itself. What is so important about ATP? (more detail) • When the last bond in ATP is broken energy is released – this is the energy that fuels cellular processes • This results in ADP + a phosphate ion (respiration ‘recharges’ this back to ATP (HARDER) Respiration “the process by which energy is released from food” • Cellular respiration involves the breakdown of glucose molecules. Respiratory enzymes convert glucose into carbon dioxide and water, and capture the energy released in the process in ATP molecules. • The ATP molecules provide the energy needed for all other cellular processes. • This energy is essential as it is used to join small molecules together to make larger ones (metabolism). It enables muscle cells to contract so that mammals can move. It is necessary for the active transport of chemicals. If these processes were not to happen the animal would not survive, as it would be unable to move, feed, grow or repair itself. • Respiration also produces the heat that keeps the body of warm blooded animals above environmental temperature. Aerobic Respiration (requires oxygen) Glucose reacts with oxygen to produce carbon dioxide and energy (in the form of a chemical called ATP) O2 + C6H12O6 CO2 + H2O + energy(ATP) Oxygen + Glucose Carbon dioxide + Water + energy(ATP) Anaerobic Respiration (in absence of oxygen) Glucose breaks down without the use of oxygen. This produces only a small amount of energy. Glucose pyruvic acid + energy (ATP) EXTRA FOR EXPERTS: The pyruvic acid is used up in aerobic respiration so that the whole process, may look like this: Glucose pyruvic acid + energy(ATP) CO2 + H2O + energy(ATP) In yeast fermentation occurs under these conditions and produces alcohol instead of pyruvic acid. Are Potatoes Alive? Evidence for Cellular Respiration O2 + C6H12O6 CO2 + H2O + energy(ATP) What could we detect to prove a potato is alive and is respiring? Detecting Respiration O2 + C6H12O6 CO2 + H2O + energy(ATP) CO2 + H2O H2CO3 Bio1.5 Life processes related to a mammal as a consumer Part Four: Linking (relate processing of food, circulation and respiration to each other and to the overall survival of the mammal) What are the links between: • Digestion & Circulation? • Digestion & Respiration? • Circulation & Respiration? • How do each help a mammal survive? Expts & Extra Activities Digestive System Problems Choose one of the problems from below. • Indigestion • Peptic ulcers • Constipation • Diarrhoea • Tracheoesophageal fistula • Barret’s syndrome • Inflammatory bowel disease • Celiac disease • Irritable bowel disease Write a paragraph to give an account of: • The symptoms • The cause(s) • The treatment Include a labelled diagram. Possible Expts • Weet bix challenge • Starch digestion in mouth – Roberts • Pepsin activity (LifeStudy) (2013 – dil the pepsin (or order clear stuff, conc the egg) • Small intestine absorbance • • • • Fat digestion (roberts) need to order lipase Bile (ppt) Bile (LifeScience) using mustard Dissections