1.5: Intro to Protein Networks

Lactase Lab Lactose sugar is composed of galactose and glucose Lactase enzyme breaks lactose into galactose and glucose

Lactose Glucose Lactase Galactose The arrows represent the action of the enzyme Substrate Products

Enzymes convert substrates into products SubstrateProduct Enzyme

lactose lactase glucose lactose Glucose and Galactose lactase galactose

Serotonin Serotonin is a molecule called a neurotransmitter used by cells in the brain to communicate Part of its function is to regulate emotions Abnormally low amounts of serotonin in the brain can cause depression How is serotonin produced, and how can we use our understanding of it to treat depression?

Some enzymes involved in serotonin synthesis Enzyme: AAAD Substrate (start with): 5-HTP Product (end up with): serotonin Enzyme: TPH Substrate: tryptophan Product: 5-HTP Enzyme: MAO Substrate: serotonin Product: 5-HIAA 5-HIAA 5-HTP

5-HIAA 5-HTP TPH AAAD MAO Your proteins determine your characteristics…

5-HIAA 5-HTP TPH AAAD MAO Low amounts of AAAD – more or less serotonin?

5-HIAA 5-HTP TPH AAAD MAO Low amounts of MAO – more or less serotonin?

5-HIAA 5-HTP TPH AAAD MAO High amounts of MAO – more or less serotonin? So do you want lots of MAO or a little bit of MAO?

Antidepressants One type of drug to treat depression works by decreasing the activity of the MAO enzyme. These are called MAO inhibitors or MAOI’s The drug molecules have a shape that fits into the active site of the MAO enzyme and blocks it

Guiding Question: “How does variation exist between organisms?”

Vocab to know Pigment = A substance, such as chlorophyll or melanin, that produces a characteristic color in plant or animal tissue. Pigment molecules are often substrates for enzymes.

Pigment Metabolic Network for the Imaginary Bioflower Blue Flower Purple Flower Where is the variation in these flowers? Blue and Purple Flowers (Color)

Bioflowers A colorless starting molecule is converted by enzyme X to blue pigment. Next, enzyme Y converts the blue pigment to purple pigment. 1.Diagram of the pathway. (include a key) 2.Give an explanation for a blue flower. Colorless Compound Blue PigmentPurple Pigment XY

Colorless (white) molecule Blue pigment molecule Purple pigment molecule Enzyme XEnzyme Y pathway Molecule cartoons

Colorless (white) molecule Blue pigment molecule Purple pigment molecule Enzyme XEnzyme Y pathway Molecule cartoons

“Roundbuds”

Roundbuds In another type of wildflower, the roundbud, red pigment is synthesized from a white precursor by enzyme Q. 1.Draw the enzyme pathway for the roundbud. It was believed that all roundbuds were red until a knowledgeable, observant teenager discovered a meadow full of white-flowered roundbuds. 2. Using your knowledge of the synthesis pathway for red pigment, give an explanation for the white roundbud variety.

colorless (white) molecule Red Pigment molecule Enzyme Q Colorless molecule Enzyme Q Red pigment molecule

It was believed that all roundbuds were red until a knowledgeable, observant teenager discovered a meadow full of white-flowered roundbuds.

2. Using your knowledge of the synthesis pathway for red pigment, give an explanation for the white roundbud variety. White PrecusorRed Pigment Q

colorless (white) molecule Red Pigment molecule Enzyme Q Colorless molecule Enzyme Q Red pigment molecule

Continue working on the back of the worksheet.

Introduce networks in cells

Idea Journal In the last box of your Proteins Idea Journal, draw a simple network showing enzymes and substrates in a cell. In the “Explain” box, describe how proteins determine the traits of a cell.