“Coat Color in Labrador Retrievers” CocoaMidnight

Metabolic Networks Introduction

Network Review Network an interconnected or interrelated web, group, or system. Nodes members of the network Edges the relationships between the nodes

Compare and contrast these networks. Food Web NetworkCell Phone Network

Compare and contrast a food web and cell phone network The nodes The edges –Types and meaning of the relationships –Properties of the edges –Directionality of the arrows Scale of the network Boundary of network

Lactase Lab Lactose is composed of Galactose and Glucose Lactase breaks lactose into…

Lactose Lactase How can we represent this with nodes and edges?

Lactose Glucose Lactase Galactose What do the nodes represent? What do the edges represent?

Key Terms Metabolism: all the enzyme reactions occurring within a cell or whole organism Metabolite: any molecule produced by chemical reactions of metabolism

Lactose Glucose Lactase Galactose Key: Metabolites Enzyme reactions

Key Terms Metabolic Network: an interconnected set of enzyme reactions; the output of one reaction is the input of another Nodes = metabolites Edges = enzyme reactions

Lactose Glucose Lactase Galactose Key: Metabolites Enzyme reactions Lactose is produced as an output of a different enzyme reaction Galactose is used as an input to a different enzyme reaction Glucose is used as an input to a different enzyme reaction

Metabolic network Lactose Galactose Galactose PUDP-Galactose Glucose Glycogen UDP-Glucose Glucose-1-P Glucose-6-P ATP ADP Pi Nodes are metabolites Edges are enzyme reactions

Metabolic pathway Lactose Galactose Galactose PUDP-Galactose Glucose Glycogen UDP-Glucose Glucose-1-P Glucose-6-P ATP ADP Pi Nodes are metabolites Edges are enzyme reactions

A metabolic pathway is a series of enzyme reactions connecting one metabolite to another –Like a single food chain within a food web

Metabolic Network ABCD E F Nodes = metabolites Edges = enzymatic conversion

ABCD E F Nodes = metabolites Edges = enzymatic conversion X What if the enzyme converting metabolite B to C is missing?

C B A Nodes = metabolites Edges = enzymatic conversion X E F D Result: -Accumulation of B -Decrease of C, D, E, and F What if the enzyme converting metabolite B to C is missing?

“Coat Color in Labrador Retrievers” CocoaMidnight

Guiding Question: “How does variation exist between organisms?” Read: “Coat Colors in Labrador Retrievers” to help you answer this question.

Vocab to know for reading. Pigment = A substance, such as chlorophyll or melanin, that produces a characteristic color in plant or animal tissue. Skin and Hair pigments are produced in cells called melanocytes. Synthesize = to put together.

Labrador (dog) pigmentation Tyrosine Dopaquinone Brown pigment Black pigment Yellow pigment tyrosinase TRP-2 TRP-1 Nodes = metabolites Edges = enzymatic conversion

Tyrosine Dopaquinone Brown pigment Black pigment Yellow pigment tyrosinase TRP-2 TRP-1 Nodes = metabolites Edges = enzymatic conversion What happens if the enzyme TRP – 1 is missing? Black pigment What color is the dog’s coat?Brown

Tyrosine Dopaquinone Brown pigment Black pigment Yellow pigment tyrosinase TRP-2 TRP-1 Nodes = metabolites Edges = enzymatic conversion What happens if both the enzymes TRP – 1 and TRP-2 are missing? Black pigment What color is the dog’s coat?Yellow Brown pigment

Pigment Networks Practice Complete the networks practice handout. Make sure you answer all questions.

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 Nodes = metabolites Edges = enzymes

“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.

White Precursor Red Pigment Q 1. Enzyme Pathway Nodes = Metabolites Edges = Enzyme

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 Nodes = Metabolites Edges = Enzyme

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