Lipids I + more Flashcards
- True or false: Are lipids hydrophobic?
True
- What are functions of lipids?
energy sources and storage
hydrophobic anchors
signaling molecules
regulators
light absorbing pigments
electron carriers
enzyme cofators
waterproof and lubricating compounds
insulation (temperature)
cushioning
- The two functional groups in a fatty acid are?
a. carboxyl group
b. ester group
c. aldehyde group
d. methyl group
A,D
- What is an aliphatic hydrocarbon tail?
open chain conformation, no rings
- What have unsaturated fatty acids?
a. loosely connected
b. contains one or more C-C double or triple bonds
c. liquid conformation
d. none of the above
- What is causing the kink in fatty acid?
double or triple bond present between carbons
- What are essential fatty acids (definition) and what is one example?
fatty acids essential for biological processes but not synthesized by the human body
-omega 3 fatty acid (initial double bond on C3)
-omega 6 fatty acid (initial double bond on C6)
- What isomer form is the most natural form of fatty acids?
a. cis-confirmation
b. trans-confirmation
c. z-enantiomer
d. e-enantiomer
a. cis-confirmation
- What are Eicosanoids?
a specific kind of polyunsaturated fatty acid (PUFA)
- signaling molecules
- What are the 3 major Eicosanoids and what processes do they regulate (one per candidate)?
- prostaglandins - associated with pain
- thromboxane - act in the formation of blood clots, reduces blood flow to site of clot
- leukotrienes - biological signals for mediators in acute and chronic inflammation
- What drugs affect the formation of PGs and TX by blocking which enzyme?
non-steroidal anti-inflammatory drug (NSAIDs) to block cyclooxygenase (COX)
- What do glycerides consist of?
esters formed from
- glycerol (3 carbon alcohol)
- fatty acids (hydrophobic)
- What is glycerol?
an ester containing alcohol on C3 and carbohydrate
- What are triglycerols/trigyceride? What are they made of ?
- a type of body fat found in the blood
- composed of an ester from glycerol with 3 fatty acid chains
- What are simple and mixed triglycerides?
Simple - no double/ triple C-C bonds
Mixed - double/ triple C-C bonds
- What are phosphoglycerides made of and what are the features of these molecules (head – tail)?
2 fatty acids chains (tail)
glycerol unit (head)
phosphate group (head)
- What major function do phospholipids have (where do we find them in a cell)?
allows for passage of molecules and ions in and out of the cell
location: cell membrane
- What are 3 major phospholipid classes (determined by their head group)?
Choline
Ethanolamine
Inositol
- Phosphatidylcholine is found in what group of lipids?
Phospholipids > lecithin
- Which neurotransmitter is lecithin-based? (bonus which retinal cells express that neurotransmitter?)
acetylcholine
amacrine cells induce retinal function
- Sphingolipids consist of?
a set of open chain aliphatic amino alcohol and sphingosine (18-C amino acid + unsaturated hydrocarbon chain
- Do Sphingolipids contain glycerol?
no glycerol
- The two major classes of sphingolipids (SLs) are – in what do they differ?
phosphosphingolipids (PSL) and glycosphingolipids (GSL) , Phosphate vs. sugar
- SLs are found predominantly what part of the cell and in which special structure?
dominantly located: cell membrane
- What is a ceramide?
sphingosine + fatty acid = backbone of PSL and GSL
- What role does GSLs have for the blood?
determines/ specifying blood type group
- Phospholipids include which types (categories) of lipids?
always contains phosphate, but not always glycerol:
- phosphoglycerides
- phosphosphingolipids
- What are steroid lipids made of (in their alcohol) form?
Sterol - steroid alcohol (contains -OH group on C-3 atom)
- What is the steroid nucleus (of what does is consist) and what synonym names does this structure have?
4-ring core (gonane/ skeletal structure)
(3) cxyclohexane rings
(1) cyclopentane ring
- What are two major functions of steroid lipids?
- components of cell membranes which alter membrane fluidity
- signaling molecules > steroid hormones
- Which molecule is the precursor of steroids in animals including us?
cholestrol
- Are sterols amphipathic and if so/or not - why?
yes, contains a polar head group and non-polar hydrocarbon tail
- What function does cholesterol have in the membrane?
- increases the order of lipid packing > lowers membrane permeability
- bidirectional regulator of membrane fluidity
- In which membrane structures is cholesterol predominantly found?
membrane bilayer
- Which structures in the nervous system are cholesterol-rich? To which cell types do these structures belong?
myelin sheaths (CNS) and optic nerve (PNS)
both associated with glial cells
- How do Eicosanoids influence cells - what are the 3 types of signaling cells ?
autocrine
paracrine
endocrine
- Cholesterol is turned into which vitamin when your skin is exposed to the sun?
Vitamin D
- Which hormones derive from cholesterol (5)?
progesterone
aldosterone
testosterone
cortisol
estradiol
- What are corticosteroids, which are the two types called? Name an example.
steroid hormones produces in the adrenal cortex of vertebrates
- glucocorticoids
- mineralocorticoids
- Which side effects can glucocorticoids have on the eye?
tunnel vision > glaucoma > cataracts
- Which hormone (belonging to which class of steroid hormones) regulates ion transport in glands?
corticosteroids > mineralocorticoids (Na/K transport)
- Which hormone is “the stress hormone”?
Cortisol
- Isoprenoids (terpenoids) are building block of which 3 major compounds?
sex hormones
vitamin A
pigments
- Which vitamin is essential for vision, and why?
Vitamin A is essential for vision, combines with protein opsin to form rhodopsin to help with rod function
- What is the name of the chromophore found in photoreceptor cells? Where (in which molecule and location in the cell) is it found?
LRAT , located in RPE
- Which two important pigments are found in the macula and what is their function?
lutein
zeaxanthin
both are associated with protection against AMD
- Lipid metabolism incudes which processes (4)?
digestion -hydrolysis
absorption
transportation
storage
lovers don’t argue through sex
- Lipids are degraded during which reaction catalyzed by which enzyme?
degradation: hydrolysis
catalysis: absorption
- The primary two lipid types that are digested in our body are?
triglycerides
cholestrol
- which sub group (name, kind) are triglycerides and cholesterol transported through the blood from the gut?
lipoproteins (chylomicrons)
- Which kinds of lipoproteins exist that transport digested fats (5)? Which one is the “dangerous” one and why?
chlyomicrons
VLDL
IDL
LDL*
HDH
*LDL is dangerous due to high cholestrol levels
- Out of which molecule (intermediate product) can fatty acids be generated – from which reaction is this molecule obtained?
generated by acetyl CoA which is a obtained from CAC
