Unit 3 BIO

• Substrate

  The molecule that is affected by the action of an enzyme
• There are thousands of different enzymes in human cells, each controlling a different reaction
• Enzymes are biological catalysts in chemical reactions
• Carbohydrases

  • Starch
  • Glucose
• Proteases

  • Protein
  • Amino acids
• Lipases

  • Fats
  • Fatty acids + glycerol
• Fermentation


  The process by which glucose is converted into ethanol and carbon dioxide in the presence of yeast
• Fermentation


  Sugar solution in the presence of yeast is left in anaerobic conditions at an optimum temperature of around 35 °C for several days
• Yeast


  A micro-organism which contains the enzyme zymase
• Yeast fermentation


  Zymase in yeast converts the sugar into ethanol and carbon dioxide gas
• Quadrat


  A piece of equipment used to identify a sample area and study the sessile organisms within it
• Sessile


  The opposite of mobile - a.k.a. non-moving
• Quadrats


  • Used to estimate the abundance and distribution of a species
  • There are three types: frame, grid, and point
• Quadrat


  Used for measuring biotic factors (living components of an ecosystem)
• Biotic factors to focus on

  • Population Size
  • Species Richness
  • Species Distribution
  • Biodiversity
• Population Size


  The number of individuals of one species living in a habitat
• Species Richness


  How many species are present in a habitat
• Species Distribution


  How species are spatially arranged in a habitat
• Biodiversity


  The measure of variety and abundance of species in a habitat
• Measuring the biotic factors of an ecosystem is useful for research and monitoring
• When combined with abiotic measurements, the data can help to draw a detailed picture of an ecosystem
• Random sampling


  Each member of the population has an equal chance of being selected
• Random sampling method


  Use a random number generator to select coordinates within the study site where quadrat measurements will be taken
• Systematic sampling


  Members of the population are chosen at uniform intervals
• Systematic sampling


  • Provides guaranteed coverage of the study site
  • Especially useful when the study site experiences an environmental gradient
• Systematic sampling method


  Quadrat locations are predetermined using a map or a transect
• Stratified sampling


  The population is divided into known groups, then sampled randomly within these groups
• Stratified sampling method


  Quadrat locations are selected randomly within the groups
• Quadrat


  A square frame (usually 1m²) that is placed directly on top of the vegetation. They are typically made of plastic, PVC pipe, metal, or wood. Any species lying within the area of the frame are identified and counted.
• Frame quadrat


  • Similar to frame quadrats, but are subdivided into squares (usually 25 or 100).
• 1. shaped quadrat


  • A T-shaped frame, where the bar of the T contains 10 long pins. The quadrat is pushed towards the ground. Different plants hit by pins are identified and counted.
• Passive sampling


  Quadrats are used in passive sampling - i.e. sampling without removing the organisms from their natural habitat. Organisms are usually counted by hand. Alternatively, you can take a photograph.
• Transect


  An environmental gradient - a change in abiotic factors through space.
• Systematic Sampling


  Transects are used for Systematic Sampling - where Samples are taken at fixed, regular intervals.
• Continuous transect


  • At continuous transects, you record vegetation along the whole length of the transect. They provide a high level of detail, but are very time-consuming to use. Thus, they're only suitable for short distances.
• Interrupted transect


  • At interrupted transects, you record vegetation at regular intervals along the transect. Using an interrupted transect is much quicker, but doesn't provide as much detail as a continuous transect.
• Quadrat sampling


  • Advantages: Simple to use, Affordable equipment, Doesn't harm the species being studied, Enables a straightforward study design
  • Disadvantages: Not suitable for mobile organisms, Can be physically demanding to use, Possibility of introducing errors: incorrect quadrat size, inappropriate spacing
• Important jobs of proteins in our bodies

  • Catalyze reactions (enzymes)
  • Help bind cells into tissues
  • Can be antibodies which protect us from pathogens
  • Transport materials
  • Carry chemical messages (hormones)
  • Control the activity of genes
• Proteins


  Big molecules that do lots of important jobs in our bodies
• Stuff is made of protein