Yr 12 endocrine

Question 1

Give the order of organization of cells to systems

Answer 1

cells - tissues - organs - systems

Question 2

What 2 systems help the body work in a co-ordinated way.

Answer 2

endocrine

nervous system

Question 3

Homeostasis

Answer 3

maintaining a stable internal environment

e.g. pH, temp, sugar level.

Question 4

Endocrine gland

Answer 4

A gland that secretes hormones directly into nearby tissue

Also called Ductless gland

Question 5

Exocrine gland

Answer 5

A gland that secretes into a duct that carries the secretion to the surface of the body cavities

Question 6

Give 4 examples of exocrine glands

Answer 6

sweat glands
mucous glands
salivary glands
alimentary canal glands

Question 7

Hormones

Answer 7

Chemicals secreted by the endocrine glands and are transported throughout the body in the blood

Question 8

Enzymes

Answer 8

Proteins that speed up chemical reactions (specific) in the body.
Type of organic catalyst

Question 9

Hormones can change…

Answer 9

The functioning of cells

Question 10

How do hormones change the functioning of cells?

Answer 10

they change the type, activities or quantities of proteins

Question 11

What effect do hormones have on enzymes?

Answer 11

change their activity

change their concentration

Question 12

What are 3 ways that hormones affect cells?

Answer 12

1. activate genes in the nucleus to make certain proteins
2. change the shape or structure of an enzyme that turns it on or off.
3. change the rate of production of an enzyme or protein.

Question 13

Can a hormone affect any cell?

Answer 13

No they can only affect cells with the right receptors

e.g. all cells, target cells, target organs

Question 14

What chemicals could be hormones?

Answer 14

steroids, proteins, amines

Question 15

Steroid hormones

Give 4 examples

Answer 15

are lipid soluble

oestrogen, progesterone, cortisol and aldosterone

Question 16

Aldosterone

Answer 16

hormone that regulates blood pressure

Question 17

How are steroids transported?

Answer 17

They bind to transport proteins and are carried in the blood.

Question 18

What happens when steroid hormones reach the target cells?

Answer 18

They separate from the transport protein and diffuse across the cell membrane.
Once inside they combine with a receptor protein
(cytoplasm or nucleus ).

Question 19

Hormone-receptor complex

Answer 19

Hormone connects to receptor protein.

Activates genes that control the formation of specific proteins.

Question 20

How does the hormone-receptor complex activate protein formation?

Answer 20

It binds to a promoter section of a certain gene, starting (or inhibiting) transcription, and therefore protein synthesis.

Question 21

Do steroid hormones act quickly?

Answer 21

No, but the effect is long lasting.

Question 22

transcription

Answer 22

DNA is copied to RNA.

Question 23

translation

Answer 23

RNA is used to make proteins

Question 24

What type of hormones are water soluble?

Answer 24

Protein and amine

Question 25

Why can't protein/amine hormones unable to diffuse a cell membrane?

Answer 25

They are not lipid soluble.

Question 26

How do protein/amine hormones activate a target cell?

Answer 26

They attach to a receptor protein in the membrane of the target cell. This hormone-receptor complex triggers a secondary messenger chemical to diffuse through the cell and activate a particular enzyme.

Question 27

What type of hormone is insulin?

Answer 27

protein | It binds to the receptor protein of a cell and increases the amount of glucose the cell absorbs.

Question 28

Do proteins/amines act quickly?

Answer 28

Yes, but the effect is short lasting.

Question 29

"receptor proteins are specific" | What does this mean?

Answer 29

each type of receptor will bind with only one type of molecule,

Question 30

What analogy can be used for receptor proteins?

Answer 30

lock and key

Question 31

What is meant by the term "saturation" in regard to receptor proteins?

Answer 31

no more receptor proteins are free to bind .

Question 32

if a cell is saturated with insulin molecules, what would happen if more glucose is taken into the body?

Answer 32

The cell cannot take on any more hormone, so the glucose will increase in concentration in the blood.

Question 33

Do all cells have the same type and number of protein receptors?

Answer 33

no - each type of cell is different, so has different sensitivity to a hormone.

Question 34

Does one hormone make one enzyme molecule?

Answer 34

No, one hormone molecule may make thousands of enzyme molecules. The process is called enzyme amplification

Question 35

What type of reaction is an enzyme amplification?

Answer 35

cascade reaction

Question 36

How are hormones turned off?

Answer 36

The hormone molecules are broken down.

Question 37

Where are hormones broken down? | How are they excreted?

Answer 37

liver and kidneys | Degrade hormones are excreted in bile or urine

Question 38

Why must the amount of hormone released be strictly controlled?

Answer 38

to maintain homeostasis

Question 39

What type of feedback controls hormone production?

Answer 39

negative feedback

Question 40

What is negative feedback?

Answer 40

the response produced by the secretion of the hormone is opposite of the stimulus that caused the secretion.