The Light Independent Reactions The Light Independent reactions take place in sunlight. If ATP and NADPH are provided, they can be carried out without light (dark reactions). Like the light-dependent reactions they occur in the chloroplast but in the area surrounding the thylakoid membranes called the stroma.

The Light Independent Reactions The light independent reactions are also called the Calvin Cycle. This is because the reactions form a cycle and were discovered by Melvin Calvin. The Calvin cycle reactions use carbon dioxide (CO2) along with ATP and NADPH, which were formed by the light reactions, to produce PGAL.

The Light Independent Reactions PGAL (phosphoglyceraldehyde) is a molecule that is used to make glucose and other organic compounds (e.g., amino acids & lipids). Glucose is made because it is more stable and can store more energy than either NADPH or ATP. To summarize, the light independent reactions provide the raw materials that are used to make most of what the cell needs to survive.

Light Reactions  produces ATP produces NADPH H2O ATP O2 light energy  + NADPH H2O sunlight produces ATP produces NADPH releases O2 as a waste product Energy Building Reactions NADPH ATP O2

Calvin Cycle  builds sugars uses CO2, ATP & NADPH recycles ADP & NADP C6H12O6  + NADP ATP NADPH ADP CO2 builds sugars uses CO2, ATP & NADPH recycles ADP & NADP back to the light-dependent reactions to make more ATP & NADPH ADP NADP Sugar Building Reactions NADPH ATP sugars

Photosynthesis

The Light Independent Reactions

The Light Independent Reactions

What factors affect photosynthesis? 1. Temperature: Photosynthetic enzymes function best between 0°C (32°F) and 35°C (95°F). 2. Light: High light intensity increases the rate of photosynthesis, up to a certain level. 3. Water: A shortage of water can slow or even stop photosynthesis.

GLYCOLYSIS AND RESPIRATION glucose (sugar) + oxygen carbon dioxide + water C6H12O6 + 6O2 6CO2 + 6H2O Energy stored in chemical bonds of glucose can be used when the bonds are broken. Cells capture the energy of glucose through the processes of glycolysis and respiration.

GLYCOLYSIS Glycolysis, which means glucose breaking, is the first phase in the break down of glucose. It is an anaerobic phase because it takes place without oxygen. It takes place in the cytoplasm of the cell. It requires two molecules of ATP to start the process.

GLYCOLYSIS During the process, the 6-carbon glucose is split into two 3- carbon PGAL molecules. The two PGAL molecules are then transformed into two molecules of pyruvic acid. During the process, 4 molecules of ATP are produced, resulting in a net gain of 2 ATP. Also, 2 NADH molecules are produced. NADH is an energy-storing compound.

GLYCOLYSIS Summary: In glycolysis, glucose is changed by enzymes into different molecules one step at a time through a series of chemical reactions. The initial glucose molecule is broken down and transformed into the final product, which is two molecules of pyruvic acid.

GLYCOLYSIS