8 - The fats of life Flashcards
Fatty acids that have one or more double bonds in their hydrocarbon tail are said to be ______. Fatty acids without double bonds are _______.
Fatty acids that have one or more double bonds in their hydrocarbon tail are said to be unsaturated. Fatty acids without double bonds are saturated.
fatty acids with double bonds below C__
cannot be synthesised by man and are an
essential dietary component.
C10
What does the omega sign mean in terms of fats?
Omega means the double bond location starting from the opposite end of the chain.
Two of the glycerol –OH groups are linked to ___.
The third glycerol –OH group is linked to ___.
This phosphate is further linked to _____.
Two of the glycerol –OH groups are linked to fatty acids.
The third glycerol –OH group is linked to phosphoric acid.
This phosphate is further linked to one of a variety of small polar groups (alcohols)
What is the precurser of all steroid hormones?
cholesterol
What are the hydrocrabon tails in glycolipids called?
What residue does the polar region contain?
Sphingosine
Fatty acid
Sugar residue (e.g. galactose)
What are the 3 main sections of the cholesterol structure?
Polar head group
Rigid steroid ring structure
Nonpolar hydrocarbon tail
Explain why lipids aggregate in water
Each lipid molecule forces surrounding H20 molecules to become highly ordered, as it contains a hydrophobic tail. This level of order is entrophically undesirable.
Therefore if lipid molecules cluster, fewer h20 molecules have to be ordered to surround it, and entropy is increased.
How many kjoules in 1gram of fat?
37
Where does degradation of fatty acids occur?
Where does synthesis occur?
Deg - Mitochondria
Synth - Cytosol
What 4 things are needed to convert acetyl-CoA into Malonyl-CoA
ATP, HCO3-, CO2-, Biotin-carboxyl-carrier protein.
What are the precursers to cholesterol?
Acetate -> Acetyl CoA Mevalonate Activated isoprene squalene cholesterol
Cholesterol degradation:
1. Mammals cannot _____ cholesterol to CO2 and H2O
2. The major breakdown pathway is conversion to
____ to assist ___ digestion and absorption
3. ______ are ultimately lost in the faeces
4. Cholesterol is the precursor for most ____
hormones
5. Traces of _____ are lost in the urine
Cholesterol degradation:
1. Mammals cannot oxidise cholesterol to CO2 and H2O
2. The major breakdown pathway is conversion to
bile acids to assist lipid digestion and absorption
3. Bile acids are ultimately lost in the faeces
4. Cholesterol is the precursor for most steroid
hormones
5. Traces of steroids are lost in the urine
