Question

1. How does the stacking of thylakoids and folding of cristae in chloroplasts and mitochondria reflect their function?

2. The cell to the left is packed full of mitochondria and contains a series of branching tubules inside of the cell. The interior of the tubules are connected to the external environment. What kind of function can derive from this cell given its structure?

Answer 1

1) Chloroplasts contain a system of membrane sacs called the thylakoids some of which are stacked to form grana , whereas others float freely in the stroma . The electron carriers which are important for the process of photosynthesis reside over these thylakoids.

This thylakoid acts as the site for light dependent photosynthesis to occur in chloroplasts .

cristae are the folds of the inner mitochondrial inner membrane that helps in increasing the surface area. The electron transport chain and chemiosmosis takes place on this membrane as a part of cellular respiration to create ATP . The cristae provides a larger surface area of the inner membrane allowing for the faster production of ATP as there are other more places to perform this process.