Hormones

Question 1

What are endocrine glands?

Answer 1

Clusters of secretory cells derived from epithelial tissue.

Question 2

What are hormones?

Answer 2

Chemicals are released by endocrine glands that regulate other distant cells in the body.

Question 3

What is hormone specificity?

Answer 3

• Hormones bring about a specific response in specific effector cells.
• Binding to specific receptors specific to the hormone + its action.

Question 4

What is the neuroendocrine system?

Answer 4

• Senses and detects information.
• Organisises + coordinates targeted responses.
• Delivers messages to specific organs or tissues.

Question 5

What are signalling differences between the endocrine and nervous systems?

Answer 5

• Hormones are secreted into + are carried via the bloodstream.
• Hormonal action on the organ or tissue brings about the intended response.
• Hormones will only act on the tissues containing the specific receptor for it.

Question 6

What are the 3 different hormone types?

Answer 6

• Amines.
• Peptides.
• Steroids.

Question 7

What are Amine hormones?

Answer 7

• Single amino acids are modified to form amine hormones.
• Hydrophilic.
• Therefore are lipophobic.

Question 8

Outline how amine hormones function.

Answer 8

1. Amine hormones are membrane insoluble. They bind to membrane receptors.
2. The binding activates a G protein.
3. The activated G protein activates adenylyl cyclase.
4. Adenylyl cyclase catalyzes the conversion of ATP to cAMP, the secondary messenger.
5. cAMP activates protein kinases.
6. Protein kinases phosphorylate proteins in the cytoplasm.

Question 9

What are peptide hormones?

Answer 9

• Short peptide hormones.
• And polypeptide hormones.
• Hydrophilic.

Question 10

Outline how peptide hormones function.

Answer 10

1. Amine hormones are membrane insoluble. They bind to membrane receptors.
2. The binding activates a G protein.
3. The activated G protein activates adenylyl cyclase.
4. Adenylyl cyclase catalyzes the conversion of ATP to cAMP, the secondary messenger.
5. cAMP activates protein kinases.
6. Protein kinases phosphorylate proteins in the cytoplasm.

Question 11

What 2 hormones function the same way?

Answer 11

• Amine hormones.
• Peptide hormones.

Question 12

What are steroid hormones?

Answer 12

• Cholestral derivatives.
• Hydrophobic.
• Lipid soluble hence capable of crossing the cell membrane.

Question 13

Outline how steroid hormones function.

Answer 13

1. Steroid hormones will diffuse through the plasma membrane.
2. Hormones bind with the receptors in the cytoplasm, forming the receptor-hormone complex.
3. Receptor-hormones complex enters the nucleus + triggers gene expression.
4. Transcribed mRNA is translated into proteins that alter cell activity.