All cells need....you guessed it!!! ENERGY!
This week we venture into the processes of photosynthesis and cellular respiration.
We will first speak about how inorganic molecules (carbon dioxide and water) are combined using the energy gathered from the sun to create organic molecules for that organisms and others to break down later for energy.
This fancy process is known as photosynthesis because light (photo) is used to combine (syn) the inorganic molecules to make organic molecules.
There is a similar process called chemosynthesis that uses the energy from chemicals as the combining factor, but we will focus on the process involving light.
Photosynthesis depends on chlorophyll whether it is housed in the chloroplast like in a plant or free floating in the cytoplasm of a bacterial cell.
We will focus on the process that involves the chloroplast. This green pigment traps light energy and converts it into ATP (chemical energy) that cells can use to combine the carbon dioxide and water to make simple sugars like glucose.
Just to review the structure of the cholorplast:
1. Inside there are stacked membranes. Each "tire" is a thylakoid filled with chlorophyll. Each "stack of tires" is known as a grana. The area around these stacks is known as the stroma.
2. Own set of DNA that allows the choroplast to self replicate when needed.
3. Double membrane.
Just to review the function of the cholorplast:
1. Each thylakoid filled with chlorophyll collects sunlight and converts it to ATP.
2. The area around the thylakoids (stroma) is where the food is made.
We will continue our discussion of cellular energy tomorrow as we look at the importance of light in the process of photosynthesis by denying some aquatic plants light while exposing others.
Finally below is a link for a review exam for both cell anatomy and plasma membrane structure and function.