CHEM 101B: chem 101 test 4
24 Cards in this Set
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sphingolipids (s-myelins)
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amino alcohol
provides hydrophobic tail
2nd tail from a fatty acid acyl group
amide link connected to NH2
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glycolipids
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derived from sphingosine.
have no phosphate group, sugar polar head.
have a small carbohydrate
reside in cell membranes with their carb. sego. that extend to fluid surrounding the cell.
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steroids
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4 rings
3 (cyclohexane)
1 (cyclopentane)
no fatty acids
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cholesterol
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most abundant steroid in body
hydrophobic except for OH group
distributed among the hydrophobic tails of phospholipids.
needed for cell membranes
important molecule for hormone, vitamnD & bile salts.
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eicosanoids
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derived from a 20-carbon unsaturated fatty acids.
synthesized throughout the body.
short lived chemical messengers that act near their point of synthesis.
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Fatty Acids
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hydrophobic
essential to lipid bilayer
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waxes
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long chain fatty acids
bonded with long chain alcohols
solid at normal temp.
hydrophobic.
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triacylglycerol
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three fatty acids linked to one glycerol molecule
also called a fat or a triglyceride
Glycerol + 3 fatty acids
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Soaps
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amphipathic molecules
has hydrophobic and polar regions
Micelles
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Micelles
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spheres formed when phospholipids are added to water
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active transport
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needs energy to maintain concentration gradient.
it transforms from ATP to ADP
changes the shape of the sodium/potassium pump
bringing two K+ ions into the cell and moving three Na+ ions out of the cell.
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simple diffusion
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no proteins required
passive transport...a substance moves down it's concentration gradient without the use of a carrier molecule
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Facilitated Diffusion
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Moves down its gradient
Works well for small hydrophilic molecules
Needs a helper protein
Ex: ions, water, glucose
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lipoproteins
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micelle structure
less dense than proteins
types are Chylomicrons, VLDLs, LDLs, HDLs
highest Cholesterol in the body are LDL's.
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Transporting lipids in body
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Not soluble in water.
Transported in blood attached to certain proteins
these complexes are called lipoproteins.
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Beta Oxidation
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Breaks down fatty acids into two-Carbon fragments
enters the Citric Acid Cycle as Acetyl CoA.
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Beta Oxidation contd.
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series of 4 reactions
oxidation, hydration,2nd oxidation, cleavage.
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ATP and B-Oxidation
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activation of fatty acid requires 2 ATP
one cycle NADH= 3 ATP
one cycle FADH= 2 ATP
acetyl-S-CoA entering the citric cycle produces 12 ATP
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ketone bodies
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produced in the liver from acetyl-S-CoA
can be used for energy by muscle & brain tissue.
helpful throughout starvation
too much can be bad, leading to ketoacidosis and blood pH levels will drop.
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Lipogenesis
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Making fatty acids from non-fat substances such as carbs, amino acids and alcohol.
Occurs when consuming excess calories
Occurs in the liver
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fatty acid Oxidation
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in mitochondria
enzymes different from synthesis
carried by coenzyme A (FAD & NADH+
Carbon atoms removed two at a time
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fatty acid Synthesis
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in cytosol
enzymes different from oxidation
carried by acyl carrier protein
coenzymes (NADPH)
carbon atoms added 2 at a time
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Urea Cycle
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catabolic-breaking down amino acids from diet.
anabolic- requires ATP,building Urea from ammonia.
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amino acids
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ketogenic- increases acetyl CoA
Glucogenic- used to form glucose.
can be both
can build new proteins
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CHEM 101B: chem 101 test 3