The light independant reactionCarissa Fletcher

This can happen in the dark

• Enzyme controlled

• Located in the stroma of the chloroplast.

• Occurs simultaneously with the light dependent reaction but it can continue in the dark provided the necessary raw materials are available (CO2, NADPH + H+ and ATP)

• Enzyme controlled reaction pathways

Advances in technology

• Between 1946 and 1953 Melvin Calvin was able to utilise advances in radio carbon dating with C-14 to trace pathways in photosynthesis.

• He later went on to win the nobel prize in1961

http://www.physics.arizona.edu/ams/education/product.htm

His experiment- lollipop apparatus• Green algae, was grown in

continuous cultures, were placed in the "lollipop" with the light shining on them.

• Carbon-14 labelled CO2 was injected into the stream of non-radioactive CO2 for a suitable period.

• At the end of which the algae were killed. The compounds into which the radioactive carbon had entered were analyzed by paper chromatography.

http://www.tokresource.org/tok_classes/biobiobio/biomenu/photosynthesis/

The Calvin Cycle

http://en.wikipedia.org/wiki/Calvin_cycle

Simplified

http://saburchill.com/chapters/chapters.html

The molecules

Glycerate-3-phosphate (GP)

Ribulose biphosphate (RuBP)

Rubisco (The enzyme)

Triose Phosphate (TP)

Other notes ATP is needed to add Hydrogen ions and electrons to the GP to make it into a carbohydrate.

The ratios

• RUBP is both consumed and produced in this reaction.

• If 3 molecules are used six TP are produced.

• 5 of those 6 return to the cycle to regenerate the RUBP

• 1TP is produced• To produce one glucose molecule 2 TP

are needed.