Lipids and Carbohydrates Flashcards
What is a monosaccharide?
A carbohydrate made up of a single sugar residue
What is a disaccaride?
A carb made up of two sugar residues
What is a polysaccharide?
A carb made up of numerous sugar residues
What is an aldose?
A carb whose carbonyl group is an aldehyde
What is a ketose?
A carb whose carbonyl group is a ketone
Lipid
A biomolecule that is largely hydrophobic and thus insoluble in water
Fatty acid
a carboxylic with a long hydrocarbon side chain
Amphiphilic/amphipathic
a molecule that has both hydrophilic and hydrophobic portions
Saturated
A fatty acid that is fully reduced (only single bonds)
Unsaturated
A fatty acid containing double bonds (has kinks)
Furanose
A five-membered ring heterocycle
Pyranose
A six-membered ring heterocycle
Glyceraldehyde
C3H6O3
Glycerol
C3H8O3
Glucose
C6H12O6 (epimer of galactose)
Galactose
C6H12O6 (epimer of glucose)
Fructose
C6H12O6 (structural isomer of glucose and galactose)
Lauric Acid
Saturated
12:0
CH3(CH2)10COOH
Palmitic Acid
Saturated
16:0
CH3(CH2)14COOH
Stearic Acid
Saturated
18:0
CH3(CH2)16COOH
Palmitoleic Acid
Unsaturated
16:1n-7
CH3(CH2)5CH=CH(CH2)7COOH
Linoleic acid
Unsaturated
18:2n-6
CH3(CH2)4(CH=CHCH2)2(CH2)6COOH
Arachidonic Acid
Unsaturated
20:4n-6
CH3(CH2)4(CH=CHCH2)4(CH2)2COOH
EPA
Unsaturated
20:5n-3
CH3CH2(CH=CHCH2)5(CH2)2COOH
DHA
Unsaturated
22:6n-3
H3CH2(CH=CHCH2)6CH2COOH
alpha anomer
OH is on the opposite side of the ring as the C6 carbon (trans)
beta anomer
OH is on the same side of the ring as the C6 carbon (cis)
anomeric carbon
always C1
Cellulose
- plant structure
- beta linkages
- every other glucose is inverted
Amylose
- plant energy storage
- alpha linkages that humans can digest
- no branching but the chains have a helical structure - 8 glucose residues per turn
Glycogen
- animal energy storage
- alpha- 1,4 linkages create straight chain and alpha - 1,6 linkages create branching
- branching increases glucose breakdown as enzymes can take glucose from multiple branches
- helical shape
How does saturation affect melting point?
- MP decreases with unsaturation (increase in double bonds)
- the longer the saturated chain, the higher the melting point
TAGs
- triglycerides: glycerol and three fatty acids
- fatty acids are fed into beta oxidation -> longer the chain, the more energy it can produce
- longer form of energy: hydrophobic and higher energy density per gram
How is fluidity controlled?
- if temperature rises, cell membrane fluidity increases so the # of saturated fatty acids increases
- if temperature decreases, cell membrane fluidity decreases so the # of unsaturated fatty acids increases
Glycerophospholipids
- structure: glycerol attached to saturated fatty acid, unsaturated fatty acid, and polar head group
- precursor: phosphatidic acid
PIP2
- second messenger in a variety of signaling pathways
- head group is cleaved and moved down to initiate and continue signaling cascade
Sphingolipids
- structure: sphingosine attached to fatty acid and PO4- choline
- precursor: ceramide
Lateral Diffusion
- phospholipid moves next on same membrane
- faster than transverse
Transverse Diffusion
- phospholipid moves from one membrane to another side
Flippase
- specific
- ATP-driven
- flips back inward
- phosphatidylserine and phosphatidylethanolamine
Floppase
- specific
- ATP-driven
- flips back outward
- sphingomyelin and phosphatidylcholine
Scramblase
- non-specific bidirectional movement
- Ca 2+ -> high levels of Ca 2+ triggers apoptosis and inhibits flippase and floppase
Eicosanoids
- local hormones
- derived from archidonic acid
- autocrine and paracrine signaling
- huge role in inflamatory responses
Sterols
- global hormones
- derived from cholesterol
- endocrine signaling
- plays a role in components of membranes and signaling across the body
