test

• Net movement


  Overall movement of particles when the movement of particles in one direction is greater than the movement of particles in the opposite direction

  
• Surface area-to-volume ratio


  The rate of food and oxygen intake is slower as the cell grows larger

  
• It is not beneficial for the cell to grow too big
• Water molecules


  Osmosis is a special form of diffusion that refers to water molecules only

  
• Osmosis is a special form of diffusion, so the characteristics of movement and factors affecting movement are similar to diffusion

  
• Comparison of concentrated and diluted solutions

  • Concentration of solute: High in concentrated, Low in diluted
  • Water potential of solvent: Low in concentrated, High in diluted
• Cells as living osmotic systems


  • A living cell is enclosed by a partially permeable membrane
  • A plant cell behaves differently from an animal cell when placed in solutions of differing water potentials due to its cell wall
• What happens to a cell in a solution with higher water potential

  1. Water enters by osmosis

  2. Cell expands and becomes turgid

  3. Cell wall prevents cell from bursting

  
• What happens to a cell in a solution with lower water potential

  1. Water leaves by osmosis

  2. Cytoplasm shrinks away from cell wall and cell becomes plasmolysed

  3. Cell becomes flaccid

  
• Crenation


  (animal cell) Shrinkage of cell as water is lost and cell forms little spikes
• Plasmolysis


  (plant cell) Shrinkage of cytoplasm and detaching of cell membrane from cell wall
• Flaccid

  (plant cell) Soft
• Turgid


  (plant cell) Swollen and Firm
• A cell immersed in a solution with the same water potential as its cytoplasm will not change its size or shape

  
• Hepatic portal vein


  Transports nutrients from small intestine to liver
• Hepatic portal vein


  Carries absorbed sugars and amino acids to the liver
• Hepatic vein


  Transports absorbed sugars and amino acids to the different parts of the body
• Research


  A general process
• How the environment in the school changes over time
• Temperature is highest at noon
• Designing fieldwork


  1. Ease of data selection

  2. Identify patterns and trends

  3. Assess perceptions of quality of green spaces in the neighbourhood

  4. Conduct interviews

  5. Make observations
• Quantitative data is more reliable than qualitative data
• Interviews can generate more in-depth and nuanced data than observations
• Observations can provide objective data on how green spaces are used
• Risks


  • Avoid harming oneself/others
• Risks to avoid include falls, minor injuries, traffic hazards and road conditions
• Measures to mitigate risks include wearing appropriate footwear and clothing, and taking note of hazards
• Catalyst


  Anything (a person, thing or event) that quickly causes change or action
• Catalyst


  • Pete and Linda's son's death
  • Jake's termination from his job
  • The offer of a new job overseas
  • Singapore
  • The bombing attack
• Catalyst (in science)


  A substance that speeds up the rate of chemical reactions
• Catalysts speed up the rate of chemical reactions
• In living organisms, the catalysts are called enzymes
• Enzyme


  A biological catalyst made of proteins that is involved in metabolic reactions
• Enzyme


  Speeds up chemical reactions by lowering activation energy

  
• The mass of the catalyst does not change at the end of the reaction
• Activation energy


  The energy needed for a chemical reaction to be activated

  
• Catalyst


  Provides an alternative pathway with lower activation energy for the reaction
• Enzyme


  A protein molecule that functions as a biological catalyst
• Catalyse


  To speed up
• Reactions enzymes catalyse


  • Reactions that build up complex substances
  • Reactions that break down complex substances