AP Biology Discussion Notes

Wednesday 10/29/2014

HAPPY LAB DAY!!!

Goals for the Day

1. Be able to do paper chromatography & EXPLAIN what is happening

2. Be able to describe the multiple pigments in leaves of a plant and why they are necessary.

Question of the Day 10/29

What are the 2 main pigments in typical green-leaved plants?

Question of the Day 10/29

What are the 2 main pigments in typical green-leaved plants?

Chlorophyll A & Chlorophyll B

Both of these pigments are the MAJOR pigments involved in photosynthesis, although other accessory pigments that help photosynthesis and still other pigments (ex. Anthocyanins) that protect the plant by absorbing light that might otherwise damage plant tissues.

Take out your yellow lab sheets

ChromatographySorts based on……• Solubility in solvent

– Greater Solubility =

• Molecular weight – – Greater weight =

ChromatographySorts based on……• Polarity(H-bonding)/Hydrophobicity

– Greater similarity between solvent & pigment =

• Adhesion to Paper– Greater adhesion =

Chromatography

• Paper –

• Solvent –

Chromatography Lab• Write out your justifications – place each

pigment where you think it belongs.

• Show me one per group– then staple to other half of lab

• Complete lab with spinach, clean up and do analysis questions together – remembering that YOU are responsible for being able to explain what is happening in this lab.

Chromatography Lab• Write out your justifications – place each

pigment where you think it belongs.

• Show me one per group– then staple to other half of lab

• Complete lab with spinach, clean up and do analysis questions together – remembering that YOU are responsible for being able to explain what is happening in this lab.

Chromatography Lab

• On the back of predictions sheet write out whether your predictions were correct, and why you think they were or weren’t

Species of the day 10/29• Silver Maple -  Acer

saccharinum

Is chlorophyll the only pigment contained in the leaves of this plant? EXPLAIN how you know this.