Hormones

Question 1

what are hormones

Answer 1

Hormones are a secretion of an endocrine gland. Target cells have specific receptor sites which match a specific hormone shape. These receptor sites can become saturated.

Question 2

what are the three main groups of hormones

Answer 2

1. proteins
2. amines
3. steriods

Question 3

describe how protein and amine hormones work

Answer 3

These hormones will attach to a receptor protein on the target cell membrane. The secondary messenger (cyclic AMP) will diffuse through the cell and activate a particular enzyme in the cytosol.

Question 4

describe how steroid hormones work

Answer 4

As steroids are fat soluble they are capable of passing directly through the bi-lipid layer into the target cell. It will combine with a receptor protein inside the cell forming the hormone-receptor complex. The hormone-receptor complex will enter the nuclues and find a gene of interest. This gene will be switched on and will make a specific protein.

Question 5

what is one thing protein and amine hormones do to cells

Answer 5

They change the shape of enzymes to turn them on or off.

Question 6

what are two things a steroid hormone does to cells

Answer 6

1. They activate certain genes to produce enzymes or proteins.
2. They change the rate of production of enzymes by changing the rate of transcription or translation.

Question 7

what is enzyme amplification

Answer 7

Is the process of hormones forming enzymes. One hormone molecule results in the activation or manufacture of thousands of enzyme molecules.

Question 8

draw two diagrams representing how protein, amine and steroid hormones work.

Answer 8

check-in writing book

Question 9

why do hormones need to be specific

Answer 9

Hormones need to be specific because they are secreted directly into the bloodstream and carried to every cell in the body. However, because of hormone specificity, it will only affect certain cells called the target cells.

Question 10

what is a hormone demonstrating its specificity

Answer 10

An example is FSH only affecting the follicles in a females ovary

Question 11

draw a comparison table between protein/amines and steroid hormones

Answer 11

Protein/amine
1. water-soluble
2. do not enter the cell
3. attach to a receptor on the cell membrane
4. uses secondary messenger (cyclic AMP)
5. secondary messenger switches on/off enzymes in the cytosol
6. fast action as enzymes are made already
7. any pituitary gland hormone

steroids
1. fat soluble
2. enter the cell
3. attach to a receptor in the cytosol or nuclues to form a hormone-receptor complex
4. does not use a secondary messenger
5. hormone=receptor complex activities gene to produce new enzymes via protein synthesis
6. slower action as enzymes have to be made
7. sex hormones

Question 12

what is hormone clearance

Answer 12

Once a hormone has produced the required effect it must be turned off. Hormones are turned off by being broken down in the target cells or the liver and kidneys. These broken down hormones are excreted in bile or urine.