biology- topic 2 organisation
- Created by: haimster
- Created on: 22-12-20 12:06
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- Biology-4.2 organisation- digestion,enzymes and plants
- The levels of organisation with living organisms:
- :1.similar cells are organised into tissues.
- 2.tissues are organised into organs.
- The products of digestion can be used to make new carbohydrates, proteins and lipids. Some of the glucose thats made is used in respiration.
- Bile= produced in liver. Stored in gall bladder before its released into the small intestine.
- :1.similar cells are organised into tissues.
- Enzymes
- Living things produce enzymes that acts as biological catalysts. They reduce the need for high temperature and we only have enzymes to speed up the useful chemical reactions in the body.
- Lock and key theory= every enzyme has an active site with a unique shape that fits onto the substance involved in a reaction, only catalyse one specific reaction because the substrate has to fit onto its active site if it dont match the enzymes active site then the reaction wont be catalysed.
- Changing the temperature changes the rate of an enzyme-catalysed reaction. Higher temp= increases rate at first but if it gets too hot, some of the bounds holding the enzyme together break= changes shape of enzyme's active site= denatured.
- Ph= if its too high or low, it interferes with the bonds holding the enzyme together= changes the shape of the active site and denatures the enzyme. It has to have the optimum ph so that they can work at its best.
- Digestive enzymes=1. carbohydrases convert carbohydrates into simple sugars. Amylase is made in 3 places: the salivary glands, the pancreas and the small intestine.
- 2. proteases convert proteins into amino acids. Made in 3 places: stomach(called pepsin there), pancreas, small intestine.
- Lipases convert lipids into glycerol and fatty acids, made in 2 places: pancreas,small intestine.
- 2. proteases convert proteins into amino acids. Made in 3 places: stomach(called pepsin there), pancreas, small intestine.
- Plants
- Plant tissues: 1. epidermal tissue= covers the whole plant.
- 2. palisade mesophyll tissue= the part of the leaf where photosynthesis happens.
- 3. spongy mesophyll tissue= also in the leaf, contains big air spaces to allow gases to diffuse in and out of cells.
- 4. xylem and phloem= they transport things like water, mineral ions and food around the plant (through the roots, stems and leaves).
- 5. meristem tissue= found in the growing tips of shoots and roots and is able to differentiate (change) into lots of different types of plant cell, allowing the plant to grow.
- 4. xylem and phloem= they transport things like water, mineral ions and food around the plant (through the roots, stems and leaves).
- 3. spongy mesophyll tissue= also in the leaf, contains big air spaces to allow gases to diffuse in and out of cells.
- 2. palisade mesophyll tissue= the part of the leaf where photosynthesis happens.
- The structures of the tissues that make up the leaf are related to their function:1. epidermal tissue= covered with waxy cuticle- helps to reduce water loss by evaporation.
- 2. upper epidermis= transparent- so light can pass through.
- 3. palisade layer= has lots of chloroplasts (where photosn takes place). This means there at the top of the leaf so they can get the most light.
- 4. xylem and phloem= form a network of vascular bundles- delivers water, other nutrients to entire leaf and take away glucose produced by photosyn- also helps support structure.
- 5. tissue of le also adapted for efficient gas exchange. e.g lower epidermis full of little holes called stomata- lets CO2 diffuse directly in leaf. The opening, closing of stomata is controlled by guard cells in response to environmental conditions.
- 4. xylem and phloem= form a network of vascular bundles- delivers water, other nutrients to entire leaf and take away glucose produced by photosyn- also helps support structure.
- 3. palisade layer= has lots of chloroplasts (where photosn takes place). This means there at the top of the leaf so they can get the most light.
- 2. upper epidermis= transparent- so light can pass through.
- Plant tissues: 1. epidermal tissue= covers the whole plant.
- The levels of organisation with living organisms:
- 3.organs are organised into organ systems.
- The digestive system breaks down and absorbs food.
- Glands(salivary glands)=produces digestive juices.
- Stomach and small intestine= digests food.
- Liver= produces bile.
- Small intestine= absorbs soluble food molecules.
- Large intestine= absorbs water from undigested food, leaving faeces.
- Small intestine= absorbs soluble food molecules.
- Liver= produces bile.
- Stomach and small intestine= digests food.
- Glands(salivary glands)=produces digestive juices.
- Its alkaline so it neutralises the hydrochloric acid in the stomach as its to acidic for enzymes to work
- Also emulsifies fats (breaks it into tiny droplets)
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