190 likes | 329 Views
Snails + Water Weeds. Snails. Ivory and blue mystery bulb snails Apple Snails Family Ampullariidae Genus Pomacea. These Ampullariidae have both a gill and a lung. Snails use photosynthesis or respiration?. Water Weeds - Wisteria. Hygrophila difformis Aquarium plant
E N D
Snails • Ivory and blue mystery bulb snails • Apple Snails • Family Ampullariidae • Genus Pomacea These Ampullariidae have both a gill and a lung
Water Weeds - Wisteria • Hygrophiladifformis • Aquarium plant • Uses photosynthesis
Lab Setup • 8 airtight containers • 4 under a light • 4 in the dark
WDYT? • What do you think? • What is going on in each container? • Why are we putting 4 containers in the dark and 4 in the light? • Why bromothymol blue? • What does this do? • Why should we have a control?
Initial Observation • What color is the water? • Will there be a change in what the liquid looks like after a couple of hours? • What gas exchange is occurring?
Get into your groups • Discuss your initial observations • Designate a speaker to talk about your group’s initial observations
Info that may change your mind… • Carbon dioxide dissolves in (and reacts with) water, forming carbonic acid, H2CO3 • CO2(g) + H2O(l) ←→ H2CO3 ←→ H+(aq) + HCO3–(aq) • The free hydrogen ions (H+) lower the pH of the solution, making it more acidic. • As CO2dissolves in water, the pH of the solution will continue to decrease (becoming acidic). If CO2 is removed from the solution, the pH will increase (becoming more basic)
Bromothymol blue • A pH indicator such as BTB can therefore indicate the relative amount of CO2 dissolved in water based on the color of the solution. • Higher pH: Blue, basic • Lower pH: Yellow, acidic
Photosynthesis is Occurring • 6CO2 + 12H2O C6H12O6 + 6H2O + 6O2 • Plant exposed to light • Removes CO2 form the solution • Raises the pH (more basic)
Cellular Respiration is Occurring • C6H12O6 + 6H2O + 6O2⎯⎯⎯→ 6CO2 + 12H2O + energy • Snail respires with or without light • Do plants have mitochondria? Can they respire? Look at Bottle 5.
Do plants have mitochondria? Can they respire? Look at Bottle 5. • Yellow Indicating acidic solution • CO2(g) + H2O(l) ←→ H2CO3 ←→ H+(aq) + HCO3–(aq) • Where did the CO2 come from?
Where did the CO2 come from in Bottle 5? • The CO2 was produced as a result of cellular respiration by the plant. • Both cellular respiration and photosynthesis occur in green plants when light is available. • In Bottle 1, photosynthesis is the dominant process over respiration, resulting in a net decrease in CO2 • HOWEVER, in the absence of light, the plant cannot photosynthesize; it can only respire • THEREFORE, there is a net increase in CO2 concentration and the pH drops as the CO2 dissolves, producing carbonic acid.
WDYT - now • Write a paragraph explaining what has occurred in the containers. • Include information about the addition of hydrogen ions or the removal of CO2 • What is an ecosystem? • What is sustainability