sicence

• Features that all living organisms have in common

  • Movement
  • Respiration
  • Sensitivity
  • Nutrition
  • Excretion
  • Reproduction
  • Growth
• Organelles that both animal and plant cells share

  • Cell membranes
  • Cytoplasm
  • Nuclei
  • Ribosomes
  • Mitochondria
• Additional organelles found in plant cells

  • Cell wall
  • Vacuole
  • Chloroplasts
• Nucleus


  Controls the activities of the cell
• Cytoplasm


  Where chemical reactions take place
• Cell membrane


  Controls what enters and leaves the cell
• Cell wall


  Made of cellulose, protects and supports the cell
• Vacuole


  Filled with cell sap, helps maintain cell structure
• Chloroplasts


  Contain chlorophyll, where photosynthesis takes place
• Red blood cell


  • Transports oxygen around the body
  • Contains hemoglobin which binds to oxygen
  • Biconcave disc shape for increased surface area
  • No nucleus to allow more hemoglobin
• Ciliated cell


  • Lines the trachea
  • Contains cilia which waft mucus and bacteria out of the airway
• Sperm cell


  • Made by testes
  • Fuses with ovum in fertilization
  • Has a flagellum to swim
  • Middle section contains many mitochondria for energy
  • Head contains acrosome with digestive enzymes
  • Haploid nucleus
• Ovum

  • Involved in reproduction
  • Haploid nucleus
• Root hair cell


  • Absorbs water and minerals
  • Has a hair-like shape to increase surface area
• Palisade layer


  • Contains many chloroplasts for photosynthesis
• You can use the simple expedient of times in 5000 to convert between the various units
• Converting units

  1. Pico meter

  2. Nano meter

  3. Micrometer

  4. Millimeter

  5. Meter

  6. Kilometer

  7. Mega meter
• Increasing temperature


  Increases enzyme activity
• Extreme pH


  Denatures enzymes
• Diffusion


  Net movement of particles from high to low concentration
• Osmosis


  Net movement of water from high to low water potential across a partially permeable membrane
• Organic compounds


  • Carbohydrates
  • Lipids
  • Proteins
• Carbohydrates


  Contain carbon, hydrogen and oxygen
• Proteins


  Contain carbon, hydrogen, oxygen, nitrogen and sulfur
• Nucleic acids


  Contain carbon, hydrogen, oxygen, nitrogen and phosphorus
• Types of carbohydrates


  • Monosaccharides
  • Polysaccharides
• Polysaccharides


  • Cellulose
  • Starch
  • Glycogen
• Proteins


  Chains of amino acids, sequence determines structure and function
• Enzymes


  Biological catalysts that speed up reactions without being used up
• Enzymes


  • Have an active site where substrate binds
  • Form an enzyme-substrate complex which then splits to form products
• Increasing temperature


  Increases enzyme activity up to optimum
• Photosynthesis


  Carbon dioxide + water -> glucose + oxygen
• Limiting factors


  Factors that limit the rate of a reaction, e.g. carbon dioxide, light intensity, temperature
• Early morning conditions


  Low temperature and light intensity limit photosynthesis rate
• In terms of photosynthesis there are three limiting factors: carbon dioxide, light intensity, and temperature
• In the early morning

  Low temperatures and low light levels limit the rate of photosynthesis
• At midday


  Carbon dioxide levels become the limiting factor for photosynthesis
• Carbon dioxide is needed by plants in photosynthesis, so it diffuses into the leaf through the stomata
• Oxygen is released by photosynthesis and diffuses out of the leaf
• Plants respire, so they need oxygen which diffuses into the leaf