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Flashcards in lipids Deck (32):
1

structural lipids

phospholipids
glycerophospholipids
sphingolipids

2

phospholipids

contain a phosphate and alcohol as the head joined to a hydrophobic fat acid tail
connected by phosphodiester bond
one or more fatty acids can make up the tail region

3

saturated fatty acids

have only single bonds
have greater van der Waals forces
more stable structure
exp. butter

4

unsaturated fatty acids

have one or more double bonds
creating kinks in the chain
this makes it difficult to stack and solidify
tend to be liquid at room temp
exp. olive oil

5

glycerophospholipids

are phospholipids
aka phosphoglycerides
contain a glycerol backbone bound to 2 fatty acids and a polar head group
head group determines membrane surface properties--> important for cell recognition, signaling, and binding

6

sphingolipids

have a sphingosine or sphenoid backbone bound to fatty acids and polar head
most are also phospholipids
divided into 4 major subclasses, differing by head group: creamed, sphingomyelins, glycosphingolipids, and gangliosides

7

ceramide

simplest sphingolipid
has sphingosine backbone, fatty acid, and single hydrogen atom as the polar head group

8

sphingomyelins

are phospholipids
have a phosphatidylcholine or phosphatidylethanolamine as the polar head group
head group has no net charge
major component of cells producing myelin (oligodendrocytes and Schwann cells)

9

glycosphingolipids

sphingolipids with head group composed of sugar bound by glycosidic bond
aka glycolipids
found mainly on outer surface of the plasma membrane
cerebrosides and globosides

10

cerebrosides

glycosphingolipid with a single sugar

11

globosides

glycosphingolipid with 2 or more sugars

12

gangliosides

complex sphingolipids
glycolipids that have a polar head group composed of oligosaccharides with one or more N-acetylneuraminic acid (NANA) at the terminus
have a negative charge
considered glycolipids
no phosphate group
role in cell interaction, recognition, and signal transduction

13

signaling lipids

terpenes and terpenoids
steroids
hormones
prostaglandins
fat-soluble vitamins

14

terpenes

metabolic precursors to steroids and other lipid signaling molecules
build from isoprene (C5H8)
produced by plants and some animals
have very strong odor

15

terpenoids

derivatives of terpenes that have undergone oxygenation or rearrangement of the carbon skeleton
modified by addition of functional groups
steroid biosynthesis
scents of cinnamon, eucalyptus, camphor, turmeric, and more

16

steroids

have 4 cycloalkan rings fused together: 3 cyclohexane and 1 cyclopentane
nonpolar
function depends on oxidation state and the functional groups attached

17

steroid hormones

steroids that act as hormones
secreted by endocrine glands into bloodstream
travel to protein carries where they bind with high-affinity receptors and alter gene expression levels

18

cholesterol

important steroid
component of phospholipid bilayer, help maintain fluidity of membrane
precursor for important molecules: steroid hormones, bile acids, and vitamin D

19

prostaglandins

20-carbon unsaturated carboxylic acid derivatives of arachidonic acid
contain one 5-carbon ring
act as paracrine and autocrine hormones
regulate synthesis of cAMP
has many downstream affects

20

fat soluble vitamins

vitamin A
vitamin D
vitamin E
vitamin K
*nonpolar hydrophobic

21

vitamin A

carotene
unsaturated hydrocarbon
important in vision, growth and development, and immune function
most significant metabolite is aldehyde form, retinal
retinol is the storage form

22

retinal

component of light-sensing molecular system of the human eye
most significant metabolite of vitamin A
in the aldehyde form

23

retinol

storage form of vitamin A
oxidized to retinoid acid, a hormone that regulates gene expression during epithet development

24

vitamin D

cholecalciferol
consumed or formed in a UV-driven reaction in the skin
in kidneys and liver its converted to calcitriol
rickets results from lack of vitamin D

25

calcitriol

biologically active form of vitamin D
formed in the liver and kidneys
increases calcium and phosphate uptake in the intestines
this promotes bone production

26

rickets

condition seen in children
characterized by underdeveloped, curved long bones as well as impeded growth
results from vitamin D deficiency

27

vitamin E

closely related to group of lipids called tocopherols and tocotrienols
substituted aromatic rings with long isoprenoid side chain
hydrophobic
rings react with free radicals, destroying them
prevents oxidative damage, important contributor to development of canter and aging
*biological antioxidant

28

vitamin K

phylloquinone (K1) and menaquinone (K2)
vital to posttranslational modifications required to form prothrombin
important clotting factor in blood
(Koagulation)
required to introduce calcium-binding sites on calcium-dependent proteins

29

triacylglycerols

triglycerides
3 fatty acids bound by ester bond to glycerol
rare for all 3 fatty acids to be the same
nonpolar and hydrophobic
storage form of energy
large amounts stored in adipocytes

30

saponification

ester hydrolysis of triglycerides using a strong base, usually lye (sodium or potassium hydroxide)
result in basic cleavage of fatty acid
leaving sodium salt of the fatty acid and glycerol
fatty acid salt is called soap

31

surfactant

lowers the surface tension at the surface of a liquid
serving as a detergent or emulsifier
soaps can act as this

32

action of soap

soap forms micelles, hydrophobic tails inward and hydrophilic heads outward
this allows for overall solvation bc non polar compounds dissolve on the inside and polar compounds dissolve in the water