Science: B2 Organisation.

• Tissue

  A group of cells with a similar structure and function.
• Organ

  A group of tissues performing a specific function.
• Organ system

  A group of organs that perform a specific function.
• Digestive system

  Mouth, Oesophagus, Liver, Stomach, Gall bladder, Pancreas, Large intestine, Small intestine, Rectum, Anus.
• Enzyme

  A biological catalyst that can speed up the rate of reaction without being used itself. Made of a large protein molecule.
• Substrate

  The chemical that fits into the active site of an enzyme.
• Lock and Key model

  Only one type of substrate can fit into the active site of an enzyme, like how a key fits into a lock.
• Denatured

  When the active site of an enzyme changes shape and the substrate can no longer fit in. Can be caused by pH or temperature.
• Starch

  Add orange/brown iodine solution. Positive result: turns blue/black.
• Sugar

  Add blue Benedic‘s solution. Place in a boiling water bath for 5 minutes. Positive result: turns green/yellow/orange/brick red.
• Protein

  Add blue Biuret solution. Positive result: turns lilac/purple.
• Lipid

  Add ethanol and decant into water. Positive result: turns cloudy white.
• Amylase

  Breaks starch into sugars. Sites of production: Salivary glands, pancreas, small intestine. Sites of action: Mouth, small intestine.
• Protease

  Breaks proteins into amino acids. Sites of production: salivary glands, pancreas, small intestine. Sites of action: stomach, small intestine.
• Lipase

  Breaks lipids (fats) into fatty acids and glycerol. Sites of production: pancreas, small intestine. Sites of action: small intestine.
• Hydrochloric acid

  Acid with a pH of 2 produced by the stomach. Uravels proteins.
• Bile

  Emulsifies fats (turns them into droplets to give a greater surface area). Its an alkaline: neutralises acid from the stomach. Produced: liver. Stored: gall bladder. Released: small intestine.
• Order of how blood flows through the heart

  1)Vena cava.

  2)Right atrium.

  3)Right ventricle.

  4)Pulmonary artery.

  5)Pulmonary vein.

  6)Left atrium.

  7)Left ventricle.

  8)Aorta.
• Lung structure (not in order)

  1)Nasal cavity.

  2)Pharynx.

  3)Larynx.

  4)Trachea.

  5)Lungs.

  6)Bronchioles.

  7)Bronchi.

  8)Alveoli.

  9)Diaphragm.
• Pacemaker

  Group of cells in the right atrium that controls resting heart rate.
• Right ventricle

  Pumps deoxygenated blood to the lungs for gas exchange.
• Left ventricle

  Pumps oxygenated blood to the body. Thick, muscular walls.
• Valve

  Stops blood flowing the wrong way/leaking.
• Alveoli

  Small sacs where gas exchange occurs. Surrounded by capillaries. Oxygen moves from the alveoli into the capillaries, carbon dioxide, moves from the capillaries into the alveoli.
• Trachea and Bronchi

  Tubes through which gases move. Lined with cartilage so they don’t collapse.