PRE-KNOWLEDGE AND SKILLS REQUIRED BY STUDENTS
Basic understanding of the biochemistry of photosynthesis. Knowledge of pH scale and the use of indicators.

TIME TAKEN IN LESSON
50 minutes

PREPARATION TIME
50 minutes

SPECIALIST EQUIPMENT AND MATERIALS REQUIRED
Sodium alginate; Hydrogencarbonate indicator; Culture of algae. A colorimeter is useful, but not essential.

CONTEXT WHERE ORIGINALLY USED
Used with students aged 14–16. Also suitable for older students, particularly if open-ended investigations are undertaken.

ADDITIONAL INFORMATION
Sodium alginate is available from suppliers of laboratory chemicals (it is also widely used in the food industry). Suppliers of other resources are listed in the protocol. The NCBE will soon supply a kit for undertaking this work. Similar arrangements may exist in other countries.

AUTHOR
Debbie Eldridge (Science and Plants for Schools)

AUTHOR ADDRESS

Please contact:
NCBE
University of Reading
2 Earley Gate
Reading
RG6 6AU