Plant hormones and Review of “P” words and Review of Animal Hormone Paris

Chemicals that make up hormones Plant:

Gases…why? Animal:

Proteins/small peptides Steroids…what is the difference about the

signaling mechanism

Light can signal hormone production in plants

Compare to animal hormone signaling mechanisms

Plant hormones to know Gibberlins Cytokinins Ethylene Abscisic acid Auxins

As we define this in the next few pages, think about how a multiple choice question could get at your understanding.

What if a plant has too much or too little?

Gibberelins Promote stem elongation Which plant is a mutant for gibberellic

acid production?

Cytokinins Promote cell division and differentiation Why would cytokinins suppress aging?

Ethylene Induces leaf abscission and promotes

fruit ripening

Abscisic acid Inhibits leaf abscission and promotes

bud and seed dormancy. Why might these two processes be

controlled by the same hormone?

Auxins Promotes plant growth and

phototropism How does this experiment show the

activity of auxin?

What hormones might be involved in germination? How?

The terrible plant p’s Phototropism Photoperiodism Photorespiration Photosystem Phytochrome

Just in case the college board puts many of these in a multiple choice!

Tropisms=“movement” in plants Phototropism=light Gravitotropism=gravity Thigmotropism=touch

What do each of these mean? What would a mutant plant look like?

Photoperiodism and phytochromes The amount of light triggers

reproduction in plants (photoperiodism!).

Phytochromes are the receptors that respond to light. Short-day plants: light receptor inhibits

flowering. Long-day plants: light receptor induces

flowering.

What could be an advantage of being a short-day plant?

Photosystems and Photorespiration

Photosystems=light reactions=good!!! Review:

Cyclic=which photosystem(s) and what is the key product?

Noncyclic=which photosystem(s) and what is the key product?

Photorespiration Calvin cycle gets O2…bad!!! Rubisco Adaptations: CAM/C4

Pep carboxylase Temporal? Structural? Bundle sheath

How about animals! Example of hormones from the brain

controlling hormones produced at glands in the body: TRH/TSH/T3 & T4 FSH/LH and their targets in males and

females Two feedback loops to know:

Insulin/Glucagon Calcitonin/PTH

Group quick presentation…find one picture that best represents the hormone system What is the gland that produces each

hormone? What are the main targets of each

hormone? Are they steriod or protein hormones? How does feedback work for the

system you studied?

RAAS and ADH Both control water balance ADH:

Produced in the hypothalamus Acts on the nephron to increase reuptake

of water back into the body Raises blood volume.

RAAS: Kidney and adrenal glands Contstricts arteries to increase blood

pressure and increases water reabsorption

Positive Feedback Oxytocin=labor and milk production in

placentals Why is positive feedback necessary

here?

Where are hormones from?

The ones from organs general have the organs in the name or we’ve talked about them!

Most of the rest come from the anterior pituitary!!!