B-2 Organisation

Differential is the process which cells become specialised for a particular job. Happens during development

• A tissue is a group of similar cells that work together to carry our a particular function • Examples include Muscle tissue Glandular tissue

• Organs are groups of different tissue that work together to carry out a function • e.g Stomach

• AN organ system is a group of organs that work together to perform a particular function • e.g digestive system Organ systems work together to create organisms

• Enzymes are catalysts produced by living things - - A substance that increases the rate of reaction without being changed or used up in the reaction

• Every enzyme has a active site with a unique chase that fits onto the substance in a reaction • usually only catalyse on type of reaction • The active light is filled with the reactant and it breaks it down to increase the rate of reaction

• Enzymes have optimum temperatures at which they work best • if too hot the bonds holding together beak and the enzyme becomes denatured • The PH also can have a similar effect

rate of reaction = Amount of substance // time taken

• It breaks down carbohydrates into sugar e. g Amalayse - Breaks down starch to sugars - Made in Saliva, pancreas and small intestine

• Protein break down proteins into amino acids - They’re made in the stomach . Pancreas. Small intestine

• Lipase converts lipids into Glycerol and fatty acids - They’re made in the pancreas and small intestine

• Bile is produced in the liver • its stored in the gall bladder before it is released into the small intestine • It emulsifies fats and neutralises stomach acid • The PH is too acidic in the stomach for enzymes so it makes it possible for it to work • It emulsifies fats giving it a higher surface area- therefore increasing the rate of reaction

• Salivary glands - Produce amylase to breakdown carbs • Gullet- To move food from mouth to stomach • Stomach- Pummels food with muscular walls. Produces pepsin. Hydrochloric acid- kill bacteria and Optimum for pepsin • Liver- Produces Bile • Pancreas- Where protease, amylase and lipase are produced. Realises to small intestine • Large intestine- Exces water absorbed • Small intestine- Enzymes active for digestion. Nutrients absorbed into blood • Rectum- poo stored

Benedict’s solution • 5cm3 of food in tube • Prepare water bath at 75oc • Add 10 drops of Benedict’s solution to test tube • Place in water for 5 mins. • If sugar is present it will change form blue to green, yellow or red depending on amount of sugar

Iodine solution • Food sample 5cm3 in test tube • Add iodine solution and shake • If starch is present it will turn blue-black or black

Biuret test • Prepare 2cm3 sample of food • Add 2cm3 of buret solution to sample and shale • If Protein is present it will change from blue to pink or purple

• Sudan III test • Prepare sample of 5cm3 of food • Add three drops of Sudan III stain solution and shake gently • If lipid is present it will separate into two layers. With a top bright red layer

• Lungs are in the Thorax • Separated from bottom part of the body by the Diaphragm • Lungs are like sponge protected by the ribcage. Surrounded by Pleural membranes _ when you breathe air it goes through the Trachea. • This splits into bronchi which go into each lung • These further split into bronchioles • These end at small bags called alveoli. Where gas exchange takes place

• Lungs contain millions of small air sacks called Alveoli • They are surrounded by blood capillaries where gas exchange happens • Blood passing next to Alveoli contains lots of co2 and little oxygen • Blood diffuses out of Alveoli into the blood. And the reverse happens into the Alveoli with co2 replacing it and breathed out • When blood reaches body cells oxygen is related from red blood cells and diffuses into body cells • At same time co2 diffuses out of body cells where it is carried to Alveoli

• Blood flows into the heart through the Pulmonary artery and Vena cava • The Atria contract oyesses blood into ventricles • The ventricles contrast and forces the blood into pulmonary artery and aorta out off heart • left side- Oxygenated • right de-oxygenated

• Your resting heart rate if controlled by a group of cells called a pacemaker • These cells produce small electoral impose when dashes surrounding muscle cells to contract • Artificial ones are often used • Located outside right atrium

• Arteries- carry blood away from the heart at high pressure. Thick walls . Layers of muscle. Thin lumen Viens- Low pressure. Carry blood to heart. Thin walls. Large lumen. valves to ensure right direction • Capillaries- Very small. Carry blood very close to every cell to exchange substances. Permeable walls. One cell thick walls

• Rate of blood flow= volume of blood// number of mins

• Red blood cells- Carry oxygen. Biconcave disc allows large surface area. Don’t have e nucleus. • White blood cells- defend against infection. Phagocytes- engulf. Lymphocytes- Antibodies. Do have a nucleus • Platelets- Small fragment of cells. Helps blood clots at wounds • Plasma- Liquid that carries the rest of the blood. Carries nutrients. cells. co2 . urea. Hormones. proteins. Antibodies