Lipids as Signals

Question 1

(a) ____ are derived from arachidonic acid and EPA

Answer 1

Eicosanoids

Question 2

The four major classes of eicasanoids are:

Answer 2

• Prostagladins
• Thromoboxane
• Leukotrienes
• Lipoxins

Question 3

What are NSAIDs

Answer 3

non-steroidal anti-inflammitory drugs that inhibit COX (cyclooxygenase)

Question 4

What are the roles of the following:

Prostagladins (4)

Answer 4

1. Smooth muscle contraction
2. Blood flow
3. Wake/sleep cycle
4. PGE3 synthesis from EPA (fever, pain, inflammation)

Question 5

What are the roles of the following:

Thromoboxane (1)

Answer 5

Blood Clotting

Question 6

What are the roles of the following:

Leukotriene (1)

Answer 6

Smooth muscle contraction

Question 7

What happens in the human body when there is an over-production of Leukotriene?

Answer 7

Asthma attacks
Anaphylactic shock

Question 8

What are the roles of the following:

Lipoxin (1)

Answer 8

Anti-inflammitory

Question 9

What stimulates Lipoxin?

Answer 9

Aspirin

Question 10

Steroid hormones carry (a) between (b)

Answer 10

a. messages
b. tissues

Question 11

(a) are oxidized derivatives of sterols

Answer 11

Steroids

Question 12

What are the structural differences between steroid hormones and cholesterol?

Answer 12

1. Lack alkyl chain attached to ring D of cholesterol
2. More polar

Question 13

How do steroid hormones reach target tissues?

Answer 13

Move through bloodstream on protein carriers

Question 14

How can steroid hormones change gene expression?

Answer 14

Bind to highly specific receptor proteins in the nucleus

Question 15

Steroid hormones
A. act locally.
B. travel through the bloodstream on lipid carriers.
C. bind to receptor proteins in the nucleus to change
metabolism.
D. have low affinity for their receptors.

Answer 15

C
Steroid hormones move through the bloodstream (on protein
carriers) from their production site to target tissues, where they
enter cells, bind to highly specific receptor proteins in the nucleus,
and trigger changes in gene expression and thus metabolism.

Question 16

Explain why you don’t need high concentrations of hormones to produce a sufficient response in target tissues?

Answer 16

Hormones have a very high affinity for their receptors, so very low concentrations of hormones are sufficient

Question 17

Which Vitanins are fat-soluble?

Answer 17

A, D, E, K

Question 18

Vitamins ____ and ____ are hormone precursors

Answer 18

A and D

Question 19

Which compound is converted in the liver to calcitriol?

Answer 19

Vitamin D3

Question 20

Vitamin D3 is/is not bioloigically active

Answer 20

is not

Question 21

What does Vitamin D3 regulate?

Answer 21

• Ca2+ uptake in intestines
• Ca2+ levels in kidney and bones

Question 22

What is the result of a vitamin D3 defficiency?

Answer 22

Ricketts

Question 23

Which vitamin do they add to milk as a precursor to vitamin D3?

Answer 23

Viramin D2

Question 24

Vitamin ____ is also known as all-trans-retinol and regulates ____

Answer 24

• A
• Gene expression

Question 25

Roles of Vitamin A

Answer 25

* Cell growth * Differentiation * Vision

Question 26

Vitamin A is synthesized from ____ or ____

Answer 26

VitA1 or β-carotene

Question 27

Where is Vitamin A stored?

Answer 27

Liver

Question 28

What does a deficiency of Vit A lead to?

Answer 28

* Birth defects * Blindness

Question 29

Vitamin A1 and its derivatives A. are involved in regulating cell growth and differentiation. B. contain only trans C–C double bonds. C. are not stored in the body in significant amounts. D. act as antioxidants.

Answer 29

A Vitamin A1 (all-trans-retinol) and its oxidized metabolites retinoic acid and retinal act in the processes of development, cell growth and differentiation, and vision.

Question 30

"Golden rice" is a genetically engineered rice producing:

Answer 30

β-carotene