Exam 4 notes

Exam 4 notes - BIOL 2150 – EXAM IV NOTES – Dr. Harmych...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: BIOL 2150 – EXAM IV NOTES – Dr. Harmych – Section 2 – MW 4:00-5:40 Exam IV Notes Chapter 41 – Animal Hormones Hormones- Chemical signals that have effects on cells in other parts of the body.- Control long term developmental processes.- Endocrine cells- Target cells- Have receptors for a hormone. Chemical Signaling Systems (a) Circulating Hormones Hormones are released into the blood stream and are carried through the body via the blood stream. (b) Local Hormones Paracrine – diffuse from site of release and bind to receptors on nearby cells. They travel locally. Autocrine – bind to receptors on the cells that secrete them. According to Evolutionary History, the endocrine system came before the nervous system. Hormonal Control of Molting- Insects undergo many molts during development.- Instar – growth stage between 2 molts.- Sir Vincent Wigglesworth- Used the bloodsucking bug Rhodnius prolixus for experiments.- Molts 5 times during development.- Each molt is triggered by a blood meal. HYPOTHESIS – Some substance diffusing from the head of Rhodnius prolixus (a blood-sucking bug) controls molting. Experiment 1 CONCLUSION – Whether a decapitated Rhodnius prolixus will molt depends on the interval between a blood meal and the decapitation, which supports the idea that a substance must pass from head to body. Page 1 BIOL 2150 – EXAM IV NOTES – Dr. Harmych – Section 2 – MW 4:00-5:40 Experiment 2 CONCLUSION – A diffusible substance is necessary for molting. Two Hormones Control Molting- Prothoracicotropic hormone (PTTH)- Brain hormone- Produced by brain cells and stored in the corpora cardiaca .- Released after a blood meal.- Ecdysone- Produced in the prothoracic gland .-Stimulates molting. Juvenile Hormone- Controls development in juveniles.- Prevents maturation.- All decapitated bugs molted directly into adults.- Experiment 3- Partial decapitation results in bugs that molt into juvenile stages.- Juvenile hormone is stored in corpora allata located in the back of the head. Complete Metamorphosis- Larvae do not look like adult organism.- Pupa- Presence of juvenile hormone prevents development into the pupa and eventually an adult. Juvenile Hormone and Insect Control- Synthetic forms are used in insect control.- Problems?- Bad bugs- Vertebrates Chemical Classification of Hormones- Peptide Hormones- Water soluble, easy transport in the blood- Insulin Page 2 BIOL 2150 – EXAM IV NOTES – Dr. Harmych – Section 2 – MW 4:00-5:40- Steroid hormones- Derivatives of cholesterol- Testosterone, estrogen- Amine Hormones- Derivatives of the amino acid tyrosine- Thyroxin Hormone Receptors- Can be on the outside or inside of a cell.- Lipid-soluble hormones- Receptors on the inside of cell- Many effect gene expression- Water-soluble hormones- Receptors are on the cell surface....
View Full Document

This note was uploaded on 04/18/2008 for the course BIOL 2150 taught by Professor Koscynski during the Spring '08 term at Toledo.

Page1 / 22

Exam 4 notes - BIOL 2150 – EXAM IV NOTES – Dr. Harmych...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online