Lipids Flashcards
What are lipids
Naturally occurring molecules that are grouped together based on being soluble in non-polar solvents
Lipids may be hydrophobic or amphiphilic
What do humans have the ability to do
They can break down and synthesise lipids in fatty acid biosynthesis
Where are lipids synthesised if not in in-vitro?
obtained from the diet
What are the 4 subgroups of lipids
- Fatty acids
- Non-glycerides
3.Glycerides - Complex lipids
What 2 things can fatty acids be
saturated or unsaturated
what 2 things can glycerides be
neutral or phosphoglyceride
what 3 things can non-glycerides be
sphingolipids, steroids, waxes
what 1 thing can complex lipids be
lipoprotein
triglycerides
glycerol + 3 fatty acids
phospholipids
glycerol + 2 fatty acids + phosphate + amino alcohol
glycolipids
glycerol (or sphingosine) + fatty acid + monosaccharide
waxes
fatty acid + long chain alcohol
steroids
3 cyclohexane + 1 cyclopentane
what is the function of lipids
- energy
- cell membrane structure
- protection
- insulation
- hormones
What is the end product of citric acid cycle
beta oxidised acetyl CoA
what is 1 gram of energy equal to
9 Kcal 38 Kjoules
what are adipocytes
energy stored in form of triglycerides in fat cells
what 3 things makes up a cell membrane
phospholipids, sphingolipids, steroids
what are steroid hormones
chemical messengers that allow tissues to communicate
what are prostaglandins
like hormones and exert effects on cells to produce them and other cells of the body
what are the lipid soluble vitamins
A (vision and skin)
D (bone health)
E (anti-oxidant)
K (blood clotting)
how do lipids help with insulation and protection
they are a protective layer for organs, they give insulation to protect against cold temps and add cushioning in fat layers- soles of feet
what foods have lipids
fruits and nuts, dairy products, eggs and meat
what grounds make up a lipid
- methyl group (CH3)
- Carboxyl group (COOH)- hydrophilic
What makes a saturated fatty acid
- No double bond
- linear structure
- general formula CH3(CH2)nCOOH
what makes an unsaturated fatty acid
- Contains a double c=c
(most double bonds are in cis configuring
what is monounsaturated
one double bond
what is polyunsaturated
more than one double bond
what is a cis fatty acid
H atoms bonded to C atom are on same side at either end of the double bond
what is a trans fatty acid
H atoms bonded to C atom are on opposite side of double bond
why does saturated fat have a higher melting point than unsaturated
due to double bond
is saturated alkanes?
yes
is unsaturated alkenes?
yes
is saturated a solid?
yes
is unsaturated a liquid?
yes
