4/16 lecture

Question 1

What is cryptochrome?

Answer 1

blue-light receptor found in the cytoplasm and nucleolus, but does not mpve; absorption of blue photons changes protein shape and allows it to bind to other proteins

Question 2

what is a chromophore?

Answer 2

part of the protein that absorbs light

Question 3

How do plants tell what season it is?

Answer 3

by the length of nights, not days

Question 4

how do circadian rhythms work?

Answer 4

rhythmic oscillations in gene expression allow plants to remember when day/night are supposed to occur; light input trains the clock; responses governed by the biological clock

Question 5

what does cryptochrome inhibit?

Answer 5

stem elongation

Question 6

Photomorphogenesis

Answer 6

COP1 suppresses light responses in the dark; activated photoreceptors release suppression by COP1