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Organisation Topic - Coggle Diagram

- - - - Practicals
      - Rate of Activity
    - - Mouth - digestion of food begins here. Teeth break down food and mix it with amylase and saliva, from salivary glands
      - Oesophagus - this is a thin tube that connects the mouth to the stomach. The food travels through it, by a process called peristalsis, a kind of wave-like contractions
      - Stomach - this is a muscular bag, which mixes food and drink with hydrochloric acid. It has to be protected, so that the acid does not dissolve the stomach itself. The enzyme protease is released here
      - Liver - this releases bile (which emulsifies fats and neutralises stomach acid) into the intestines. The emulsification of fats is helpful because it makes it easier for the enzyme lipase, to work on it
      - Pancreas - this releases all three types of enzymes into the intestines
      - Small Intestine - the nutrients, that are left after the enzymes, are absorbed into the blood, here. 2 main parts of it: duodenum (carbs + proteins are digested, digestion of lipids begins) and ileum (digestion of all 3 nutrients). Adaptations: villi and epithelia cells (large surface area), good blood supply (maintain concentration gradient) and thin walls (shorter diffusion pathway)
      - Large Intestine - food which cannot be broken down goes through here, and water is absorbed
      - Rectum and Anus - any undigested food is stored and excreted from here, as faeces
    - - 3 major types of nutrient: carbohydrates, proteins and fats
      - Carbs - source of energy; consists of sugars, starch and cellulose; if eaten in excess, can be stored as regular fat. E.g. potatoes, rice, cereal, wheat products, and sugars can be found in sweets and chocolate
      - Proteins - an organic compound that is made up of amino acid molecules, and is needed for growth and repair; can mainly be found in meats, eggs, cheese and nuts
      - Lipids (or fats) - composed of fatty acids and glycerol; are mainly used for a quick energy release; makes up parts of cell membrane, so are essential for normal growth; can be found in dairy products
      - Click the following link to learn more about the structure of each nutrient: https://www.bbc.co.uk/bitesize/guides/z89mk2p/revision/2
- - - - Waxy Cuticle - this is a sticky layer that covers the whole surface of the leaf (on the top and on the underside). It protects the leaf from getting sunburnt, and keeping most of the sun's heat off the plant
      - Upper/Lower Epidermis - they are a layer of transparent cells, that need to be so because they are above the palisade layer, and so need to be able to let light through
      - Palisade Layer - contains a lot of chloroplasts and are packed tightly, length-wise, so that more cells can fit into the same amount of space. They are at the top of the leaf, so that they can absorb the maximum amount of sunlight, possible.
      - Spongy Mesophyll Layer - this is a loosely packed cells, that have air spaces, to allow the gases to be able to, efficiently, diffuse into the palisade layer
      - Guard Cells and Stomata - guard cells (kidney shaped cells) open and close gaps in between them (stomata), to allow the diffusion of gases, in and out of a leaf. When the plant fills up with water, the guard cells fill up with with water, and become plump and turgid, so the stomata open. When they open, they also let out water, and this is part of the transpiration system.
      - Xylem and Phloem - form a network of vascular bundles, which deliver water and nutrients (via the xylem, from the roots to the leaves) and food substances (via the phloem, from the leaves to the rest of the plant). They also help support the structure of the plant