How will you know what your experimental data

How will you know what your experimental data means? Student’s Lab Notebook

Making Sense of Your Data • What data did you take? • What are some things your data requires you to understand?

Can difference in color be due to genes?

What is known about energy production in Halo?

ATP • Cells need ATP for nearly all cellular processes that require energy, including growth • Therefore, halo must be able to make ATP in the conditions that allow them to grow

MORE stored energy P P P ATP INPUT OUTPUT ENERGY FOR CELLULAR WORK CHEMICAL ENERGY ADP + P P LESS stored energy

Question #1 What makes halobacterium purple?

Halo have a purple membrane protein called bacteriorhodopsin (b. R) Halobacterium cell Bacteriorhodopsin (b. R)

Halo have a purple membrane protein called bacteriorhodopsin (b. R) Halobacterium cell Bacteriorhodopsin (b. R)

Question #2 What is the purple membrane protein made of?

Halo have a purple membrane protein called bacteriorhodopsin (b. R) Cell membrane Bacteriorhodopsin (b. R)

Bacteriorhodopsin (b. R) is made from a protein called bop and the molecule retinal Bop + retinal = bacteriorhodopsin (b. R) Retinal Bop protein Cell membrane Bacteriorhodopsin (b. R)

Question #3 What is the purpose of the purple membrane protein?

BR converts light energy into chemical energy for making ATP LIGHT ATP ATP Halobacterium cell ATP Bacteriorhodopsin (b. R) Note: other proteins are required for this process, but we will simplify and focus on b. R

BR converts light energy into chemical energy for making ATP LIGHT ATP ATP Halobacterium cell ATP Bacteriorhodopsin (BR) Note: other proteins are required for this process, but we will simplify and focus on BR

BR converts light energy into chemical energy for making ATP Cell membrane ADP + P ATP Bacteriorhodopsin (b. R) LIGHT

BR converts light energy into chemical energy for making ATP LIGHT PRESENT Cell membrane ADP + P ATP Bacteriorhodopsin (b. R) LIGHT

Halo use bacteriorhodopsin (b. R) to produce ATP using light energy LIGHT PRESENT LIGHT ABSENT (DARK) LIGHT Bacteriorhodopsin (b. R) ADP + P ATP

Halo use bacteriorhodopsin (b. R) to produce ATP using light energy LIGHT PRESENT LIGHT ABSENT (DARK) LIGHT ATP ATP ATPATP ATP ATP Halobacterium cell Halo use b. R to produce ATP for growth and metabolism Halobacterium cell Halo cannot use b. R to produce ATP

Question #4 How would amount of light and levels of purple protein be connected?

Halo change the expression of b. R in response to the amount of light in their environment LIGHT Halobacterium cell Bacteriorhodopsin (b. R)

Halo change the expression of b. R in response to the amount of light in their environment LIGHT Halobacterium cell Bacteriorhodopsin (b. R)

Halo change the expression of b. R in response to the amount of light in their environment LIGHT PRESENT LIGHT ABSENT (DARK) LIGHT Halobacterium cell When there is more light, halo respond by making more b. R LIGHT Halobacterium cell When there is less light, halo make less b. R

OUR QUESTION: How do Halobacterium cells control the amount of b. R expressed in response to light? What is the gene and protein network that regulates the expression of b. R?