Big and small

• Eukaryotic organisms are any cell or organism that possesses a clearly defined nucleus.
• Prokaryotes have no membrane-bound nucleus, while eukaryotes do
• 1.2 - Plants are multicellular uses photosynthesis, has chloroplasts, and has a cellulose cell wall
• 1.2 - Animals are multi-cellular, eats on other organisms, and have a nervous system
• 1.2 - Protoctista are single celled, and can have a cell wall, chloroplasts and a flagella
• 1.4 - Bacteria are unicellular, lack a true nucleus, and can be found everywhere
• 1.3 - Fungi is multicelled, saprotrophic nutrition, and has a chitin cell wall
• a common feature in prokaryotic organisms is they do not have a proper nucleas, and instead they have a circular chromosome
• the levels of organisms are organisms - cell - tissues - organs - organ systems
• organelles are specialised structures that carry out specific functions within the cell
• cells are the smallest functional unit of life
• tissue is made up of cells with similar structure and function
• organs work together to carry out a complex function
• organ systems carry out a complex function that's essential to life
• both the animal and plant cell have the cell membrane, nucleus, cytoplasm, mitochondria, ribosome. but the plant cell has a vacuole, cell wall and a chloroplasts.
• the nucleus control activity and contains DNA in chromosomes
• ribosomes make proteins using amino acids
• cell membrane controls what goes in and out of the cell
• vacuoles store water and waste products
• cytoplasm is where the chemical reactions occur
• mitochondria produce energy/ATP from food
• chloroplasts carry out photosynthesis
• cell wall helps the cell keep a fixed shape
• chemical elements that carbohydrates contain are carbon, hydrogen and oxygen
• Chemical elements that lipids contain are carbon, hydrogen and oxygen
• chemical elements that proteiNs contain are carbon, hydrogen, oxygen and Nitrogen
• starch and glycogen form simple sugars
• protein from amino acids
• lipids are made from fatty acids and glycerol
• The test for carbohydrates is:

  1. add benedicts solution to the food sample
  2. place in a water bath at 80 degrees for 5 minutes
  3. if it turns red (meaning highest concentration), orange, yellow or green, then carbs is present
• The test for starch is:

  1. add the food sample to a spotting tile or a test tube
  2. add orange iodine to the food sample
  3. if it turns blue or black, starch is present
• the test for protein is:

  1. add water to food sample if it isn't liquid
  2. add biuret solution to the food sample in a test tube
  3. if it turns violet/pale purple, protein is present
• the test for lipids;

  1. add ethanol to the food sample in a test tube and shake
  2. add an equal amount of water to the test tube
  3. if it turns cloudy white, lipids are present
• An enzyme is a molecule that acts as a biological catalyst by speeding up the rate of reactions
• Enzymes allow substrates to bind onto their active site, breaking them down into different products.
• as the temperature increases, the enzyme and substrate complex will have more kinetic energy, move faster, so their is more chance of Collison . too high temperatue will result into the enzyme denaturing
• prime temperature fopr enzymes to work at is 37 because that is body temperature
• how enzyme activity is affected by temperature;

  1. place drops of (food tester) e.g. iodine into a spotting tile
  2. label test tubes with different temperatures
  3. get a water bath at the temperature you are testing with cold water and a kettle
  4. use a syringe to place 4cm3 of (enzyme) e.g. amylase into the test tube
  5. place in water bath for 5 minutes
  6. syringe to place 4cm3 of (food)e.g. starch to the (enzyme)e.g. amylase
  7. after 30 seconds, use syringe to place a drop of iodine - should turn blue or black
  8. after another 30 seconds, repeat
  9. repeat until orange
  10. count iodine drops. 1 drop = 30 seconds
• if the pH is too high or low, the enzymes bonds that held the amino acid chain can be destroyed.
• optimum pH for enzymes is usually 7, but some enzymes (e.g. stomach acid) has an optimum if 2 or 8-9