Some fun things about Photosynthesis

Draw and label a diagram showing the structure of a chloroplast as seen in electron micrographs.




Explain photophosphorylation in the terms of chemiosmosis.
Photophosphorylation is the production of ATP using the energy of sunlight. The process of chemiosmosis makes photophosphorylation possible. Chemiosmosis is the movement of ions across a selectively permeable membrane and down a concentration gradient. During photosynthesis, light is absorbed by cholorphyll molecules in photosystems. Electrons within these molecules are then raised to a higher energy state; they become excited. There is a high concentration of H+ from the pumping of protons. Then, H+ accumulates in the thyhlakoid space. Protons diffuse through ATP synthase where they reduce ADP to ATP.

State the final products of the two photosystems involved in the light-dependent reactions of photosynthesis.
 The final products of the two photosystems involved in light-dependent reactions of photosynthesis are ATP and NADPH.

How are the products of the light-dependent reaction important to the light-independent reaction?
The products (glucose, amino acids, organic compounds, ATP, and NADPH)of the light-dependent reaction are very important. The light-independent reactions use these products in order to fuel their processes and carry out the Calvin Cycle. It is its reactants.

Chemiosmosis in Phosphorylation

Describe chemiosmosis as it relates to oxidative phosphorylation.

Chemiosmosis involves the movement of protons (hydrogen ions) moving across a membrane (down its concentration gradient) to provide energy so that oxidative phosphorylation can occur. Oxidative phosphorylation is a metabolic pathway that uses energy released by the oxidation of glucose to produce ATP.

Although the many forms of life on earth use a range of different nutrients, almost all carry out oxidative phosphorylation to produce ATP, the molecule that supplies energy to metabolism. This pathway is probably so pervasive because it is a highly efficient way of releasing energy, compared to alternative fermentation processes such as anaerobic glycolysis.

The Fabulous Role of Oxygen

Role of Oxygen in Cellular Respiration

Without oxygen, cellular respiration could not occur because oxygen serves as the final electron acceptor in the electron transport system. The electron transport system would therefore not be available. It is part of the process!

Glycolysis can occur without oxygen. Although glycolysis does not require oxygen, it does require NAD+. Cells without oxygen available need to regenerate NAD+ from NADH so that in the absence of oxygen, at least some ATP can be made by glycolysis.

Role of Oxygen in Photosynthesis

Oxygen is the by-product of a water molecule breaking down to supply photosystem II with electrons in the very beginning of photosynthesis.