Biology

• Features that all living organisms share

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

  • Cell membrane
  • Cytoplasm
  • Nuclei
  • Nucleus
  • Ribosomes
  • Mitochondria
• Additional organelles 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
• Ribosomes


  Where protein synthesis takes place, where proteins are made
• Cell wall


  Made of cellulose, protects and supports the cell
• Vacuole


  Filled with cell sap, helps maintain the structure of the cell
• Chloroplasts


  Contain the green pigment chlorophyll, where photosynthesis takes place
• Eukaryotes


  Animal cells, contain membrane bound organelles like nuclei and mitochondria
• Prokaryotes


  Viruses and bacteria, contain no membrane bound organelles, have strands of DNA or RNA instead of a nucleus
• Bacterial cell


  • Sometimes has a cell wall
  • Sometimes has a slime capsule
  • Sometimes has a flagella to help it move
  • Has a circular chromosome instead of a distinct nucleus
  • Has plasmids, small rings of genetic material
• Examples of pathogenic bacteria


  • Pneumococcus (causes pneumonia)
  • Tuberculosis (causes TB)
• Examples of non-pathogenic bacteria

  • Lactobacillus bulgaricus (used in yoghurt making)
• Bacteria are unicellular, made of one cell only
• Viruses


  • Much smaller than bacteria
  • Simply made of a protein coat containing DNA or RNA
  • Have no typical organelles
  • Are non-living, do not excrete, respond, grow, or reproduce
  • Are always pathogenic, there are no 'good' viruses
• Examples of viruses


  • Flu virus
  • Cold virus
  • HIV (causes AIDS)
  • Tobacco mosaic virus (causes discoloration in plant leaves)
• Protists


  • Some have animal-like properties, some have plant-like properties
  • Can be unicellular or multicellular
• Fungi


  • Have a cell wall made of chitin
  • Have a cell membrane, cytoplasm, vacuole, but no chloroplasts
  • Have thread-like structures called hyphae that form a network called mycelium
  • Carry out saprotrophic nutrition, secreting enzymes to break down dead matter and absorb the nutrients
• Examples of fungi


  • Yeast
  • Mushrooms
• Five kingdoms of life

  • Plants
  • Animals
  • Protists
  • Bacteria
  • Fungi
• Carbohydrate storage


  In animals - glycogen, in plants - starch, in fungi - glycogen
• Cell


  A group of organelles working together to perform the same function
• Tissue


  A group of cells working together to perform the same function
• Organ


  A group of tissues working together to perform the same function
• Organ system


  A group of organs working together to perform the same function
• Organism


  A group of organ systems working together to perform the same function
• Organ systems in the body

  • Digestive system
  • Endocrine system
  • Reproductive system
  • Circulatory system
  • Respiratory system
  • Nervous system
  • Excretory system
• The digestive system is made up of organs like the stomach, esophagus, pancreas, small intestine, large intestine
• The tissues in the stomach include glandular tissue that secretes hydrochloric acid and muscular tissue that helps channel food
• Zygote


  The cell formed when a sperm and egg meet at fertilization
• Enzyme


  A biological catalyst that speeds up the rate of a chemical reaction without being used up
• Active site


  The biologically active part of an enzyme molecule where the substrate binds
• Enzyme catalysis


  1. Substrate binds to active site

  2. Forms enzyme-substrate complex

  3. Complex splits to form product
• Amylase


  Enzyme that catalyzes the breakdown of starch into glucose
• Proteases


  Enzymes that break down proteins into amino acids
• Lipase


  Enzyme that breaks down lipids/fats into fatty acids and glycerol
• As temperature increases


  Enzyme activity increases up to the optimum temperature
• As temperature continues to increase above the optimum

  Enzyme activity decreases due to denaturation