Bioenergetics

• cells ➔ tissues ➔ organs ➔ organ systems
• The upper epidermis is transparent so that light can pass through it. This means that as much light as possible can reach the palisade mesophyll cells below, and be used in photosynthesis. 
• At night time, when photosynthesis can't take place, are the stomata normally open or closed? 


  closed
• Meristem tissue is made up of plant stems cells. It's found in the growing parts of the plant such as the tips of shoots and roots. 
• Which part of the plant is glucose produced in? 

  Leaves
• What do we call the movement of cell sap (a mixture of sugar and water) up and down the plant?

  Translocation
• Phloem cells have pores in their end walls to allow cell sap to pass along the phloem tube. 
• What does the xylem transport in a plant?

  Water and dissolved mineral ions
• How do root hair cells absorb water from the soil?

  Osmosis
• How do root hair cells absorb mineral ions from the soil?

  Active transport
• Which substance are xylem cells reinforced with to make them stronger? 

  Lignin
• What is transpiration?

  The evaporation of water from the leaves
• In what part of the cell does photosynthesis take place?

  In chloroplasts
• What is the word equation for photosynthesis? 

  Carbon dioxide + water ➔ glucose + oxygen
• What is the chemical symbol equation for photosynthesis?

  6CO2 + 6H2O ➔ C6H12O6 + 6O2
• What can the glucose made during photosynthesis be used for?

  Respiration and can be stored as starch for later
• What else do plants need to make amino acids?

  Nitrate ions
• • The inverse square law states that the intensity of light decreases proportionally to the square of the distance from its source.
• Why may plants produce insufficient chlorophyll?

  They have a disease like Tobacco Mosaic Virus or they lack the required nutrients 
• List the three environmental factors that affect the rate of photosynthesis.

  Light intensity 

  Amount of carbon dioxide

  Temperature 
• Respiration is the release of energy from sugar molecules such as glucose.
• What is metabolism?

  The combination of all chemical reactions in an organism 
• Give two examples of how cells use the energy from respiration.

  To maintain our body temperature

  To break large molecules into smaller molecules
• What is the word equation for aerobic respiration? 

  Glucose + oxygen ➔ carbon dioxide + water
• What is word equation for anaerobic respiration in plants and fungi?

  Glucose ➔ ethanol + carbon dioxide
• What are the two reasons animals cells prefer aerobic respiration to anaerobic respiration?

  Anaerobic respiration releases less energy than aerobic respiration and it also produces lactic acid which can damage cells and leads to an oxygen debt.