Biology B2.1,2,3

Nota:

• cells and simple cell transport tissues, organs and organ systems

1. cells and cells structure
   1. animal cells

      Nota:

      • a nucleus which controls the activities of the cell cytoplasim is where most of the chemical reactions happing a cell membrane which controls the passage of substances in and out of the cell mitrochondria, which is where oyxgen and glugose are used to relaeas energy in the process of aerobic resperation
      • ribosomes, which is where protein syntheses occurs- all the protein your body needs are made here
   2. plant cell

      Nota:

      • a cell wll made of cellulose that strenghtens the cell and gives it support chloroplasts contain the green pigmant chlorophyll and absorb light energy to make food by photosynthesis a permanent vacuole filled with cell sap which is important in keeping the cells rigid to support the plant
   3. bacteria

      Nota:

      • single living organisms that are smaller than animal and plant cells they are usually made up of cytoplasm, surrounded by a membrane and a cell wall genectic information is found in the cytoplasm, they have DNA called plasmids, some have a tail to help them move around
   4. yeast

      Nota:

      • it is usefulo to humans, it is also singled cell and has similar features as animal cell but is surrounded by a cell wall they are very important and can survive without oxygen
   5. specislised cells

      Nota:

      • root hair cell- plant cell motor neuron- animal cell xylem cell (carrys water) - plant cell pailsade layer- plant cell sperm cell- animal cell red blood and fat cell- animal cell
2. how do substances enter and leave the cell
   1. diffusion

      Nota:

      • diffusion is movement of particles or ions froma high concentration to a low consentration, down the concewntration gradient
   2. diffusion in a living cell

      Nota:

      • water, sugar (glugose), amino acids all pass across cell membrane by diffusion oxygen required for respirastion through cell membrane and through gas exchange surfaces, such as alveoli in the lungs
   3. rates of diffusion

      Nota:

      • if there is a big difference between concentrations in two areas diffusion will happen quickly. the steeper the concentration gradient the faster diffusion will happen cells help make diffusion quicker by increasing the surface area cell line on the small intestine is folded to increase the surface area so diffusion of food digested food will occur more rapidly. the fold are called microvilli
3. tissue,organs
   1. tissue

      Nota:

      • a tissue is made up of similar cells that carry out a particular function e.g. muscle tissue, glandular tissue,, epithelial tissue  in plants epidermal tissue, these cover the plant,mesophyll, xylem and phloem tissue
   2. organs

      Nota:

      • an organ is made up of different tissues all working together e.g muscle tissue, glandular tissue in plants organs imclude the leaf, stems and roots each of which has a specific job to do.
   3. organ system

      Nota:

      • different organs work together to complete a particular function make up a organ system digestive system- glands, stomach, liver, small intestine, large intestine
   4. order

      Nota:

      • cells-tissue-organs-organ sytem-organism
4. phtotosynthesis
   1. equation

      Nota:

      • carbon dioxide+water (light energy/chlorophil) glugose+oxygen
   2. during photosynthesis

      Nota:

      • light enegy is abosorbed by a green substance called chorophyll which is found in chloroplast in some plant cells and algae this energy os used by converting carbon dioxide from the air and water from the soil into sugar (glugose)
   3. glucose

      Nota:

      • glugose produced is used straight away by the cells of the plant, however a lot of the glucose made is converted into starch for storage
   4. limiting factor of photo
      1. temperture

         Nota:

         • the rate of photosnthesis increases steadily with a rise in temperture up to certain point. after this the enzymes are destroyed and the reaction stops completely
      2. carbon dioxide

         Nota:

         • if there is too litlle the rate will slow down. CO2 may be limited in an enclosed space for instance in a green house on a sunny day or in a rapidly photosynthesizing eain forest
      3. light

         Nota:

         • alack of light will slow down the the rate if photo as light provides the energy for the process 
5. how do plants use glucose

   Nota:

   • plants and alage make glucose when they photosythesis. some are used in the cells straight away for resperation for cell function such as growth and repoduction  some are are combained with outher nuterients by the plant to produce new materials
   1. starch for storage

      Nota:

      • plants make food inthe leaf of the plant, however the food is needed in all parts of the plant. it moves around the plant in transport vessels called phloem plants can store lots of starch in the plants
   2. amino acids

      Nota:

      • to make amino acids sugars must be combained with nitrate ions and other mineral ions from the soil. this energy releases from repiration.
6. maximising the yeild of a crop

   Nota:

   • the more a plant photosynthesizes the more biomass mass of living materials. it makes andthe faster it grows. farmers use the information to help them artificially grow plants in the environment that will maximize the amount of biomass and therefore profit they will produce