Name four kinds of membrane proteins and what they do?

Question

Still studying for my mid-term.

Answer 1

If one looks only at the process of photosynthesis numerous membrane proteins that occur in the thylakoid system of the chloroplast can be described.

1. Light-harvesting proteins:  these proteins have no enzymatic properties but do bind pigments such as carotenoids and chlorophylls.  They  act like antennae by collecting light and making it available to reaction centers.

2. Reaction centers: These are typically membrane protein complexes that use light energy to raise the energy level of electrons to form the substrates NADPH and ATP  which are used to convert CO2 to carbohydrate.

3. Cytochromes:  These heme-containing proteins are ubiquitous in nature and serve functions not only in photosynthesis but respiration as well.  Cytochromes are typically involved in electron transfer processes.

4. ATP synthase:  This membrane-bound protein complex is very important to photosynthesis.  It converts energy stored in the pH gradient formed across the thylakoid membrane in the light to make ATP.