Biology paper 1

• Light Microscopy


  They are cheap and allow you to see the outline of cells
• Electron Microscopy 


  You can see greater details ORGANELLES SUB-CELLULAR STRUCTURES have a higher resolution
• Mitosis 


  All human cells have 23 pairs chromosomes(46) Whereas Egg, Sperm only have 23
• Mitosis-What happens to the nucleus (1)

  Nucleus Dissolves genetic material is duplicated the new pairs move
• Mitosis-What happens to the Nucleus (2)

  Mitochondria & Ribosomes and others are duplicated
• Mitosis-What happens to the nucleus (3)

  The cell divides making new genetically identical diploids
• Specialisation (1)


  Stem cells perform specific functions they care found Animal Embryos Plant Meristems
• Specialisation- Embryo Clones 


  Made for a person to harvest cells treat conditions which are rejected in the patient body
• Specialisation (3)


  Stems cells are still made in your body only specialised into blood cells
• Diffusion (1)


  Movement of particles from an area to high concentration to a low concentration
• Diffusion (2)


  This is Passive requires no energy The rate can be increased by surface area temperature
• Active Transport (1)


  Movement of particles through a membrane via carrier proteins
• Active Transport (2)


  Requires no energy which can move them against the concentration gradient
• Osmosis (1)


  Diffusion of water across a semi-permeable membrane
• Osmosis (2)


  To balance concentrations of a solution inside and outside a cell
• Osimois (3)


  Water must move as larger molecules can’t fit through holes
• Osmosis (4)


  Water moves in if the concentration is higher outside
• Organisation 


  Cell-> Tissue-> Organ-> Organ System/ heart cell, heart tissue, heart, circulation system
• Digestive System 


  Teeth break down food mechanically, Saliva contains Amylase (an enzyme)
• Digestive system (2)


  Liver produces Bile that is stored in gall bladder before going into the small intestine
• Digestive system (3)


  Bile emulsifies lipids to form droplets increasing their surface area
• Digestive system (4)


  Stomach makes hydrochloride acid & Enzymes that chemically break down food
• Digestive system (5)


  Pancreas make amylase which breaks down starch into glucose in the small intestine
• Digestive system (6)


  Water is absorbed into the bloodstream in the large intestine
• Digestive system (7)


  Nutrients like glucose are absorbed into bloodstream by villi in the small intestine
• Enzymes (1)


  Special proteins that act biologically catalyst often breaking down molecules shorter
• Enzymes (2)


  There’re specific only break down substrates that fit in active site (lock and key)
• Enzyme (3)


  Rate of reaction increases with temp until enzyme denatures active sites change shape
• Enzymes (4)


  Same is true for too high or low PH condition for max rate/activty
• Enzymes (5)


  Carbohydrases break down Carbohydrates into simple sugars amylase breaks starch in glucose
• Enzymes (6)


  Protease break down proteins in amino acids
• Enzymes (7)


  Lipases break down lipids into glycerol & fatty acids
• Food Test (1)


  Starch-> turns iodine from orange to black
• Food Test (2)


  Sugars-> turn Benedict’s solution from blue to orange
• Food Test (3)


  Protein-> turns Biuret’s reagent from blue to purple
• Food Test (4)


  Lipids (Fat) -> turn cold ethanol cloudy
• Respiratory System (1)


  Alveoli (air sacs) have a large surface area allow gas exchange to occur at a fast rate
• Respiratory System


  Oxygen diffuses into bloodstream bind to haemogoblin in red blood cells to be transported
• Respiratory System (3)


  Carbon Dioxide and water also diffuse out
• The Heart (1)


  Double Circulatory -> blood enters heart twice every time it’s pumped round body