Lecture 2 - Lipids Part 1 Flashcards
what are the types of lipids
triacylglycerol
phospholipids
sphingolipids
sterols
fat soluble vitamins
etc
what is the most common type of lipid in our body and food
triglycerides
what are triglycerides a structural component in
lipoproteins
what is the major lipid class found in cell membranes
phospholipids
where is cholesterol found in the diet
animal products
important functions of cholesterol
- structural component of membranes
- steroid backbone
- vitamin D
- bile acids
what are the information molecules that fatty acids are an important component of
eicosanoids
what is a short chain fatty acid
C2-C6
what is a medium chain fatty acid
C8-C12
what is a long chain fatty acid
> C14
what are the melting points like of saturated fatty acids
high melting point = usually solid at room temperature
can the body synthesis saturated fatty acids
yes - so not essential in diet
what does C18 mean
18 carbons
what does the :0 mean in C18:0
no double bonds
what does a monounsaturated fatty acid have that saturated fatty acid doesnt
one cis or trans double bond
what are the melting points like of monounsaturated fatty acids
intermediate melting points
what are the melting points of polyunsaturated acids
low melting points
can the body synthesise polyunsaturated acids
the body can not synthesise n-6 and n-3 PUFA so they are essential fatty acids
what end do you count from in fatty acids
the methyl end
what does C18:2n-6 mean
it has 18 carbons, two double bonds, the double bond is 6 away from the methyl end and then CH2 seperates the double bonds
what carbon in fatty acids from the methyl end are humans unable to produce a double bond before
the 9th carbon, hence we must obtain fatty acids that have double bonds before the 9th carbon from the diet
deficiencies in essential fatty acids can lead to ….
- growth retardation
- reproductive failure
- skin lesions
- kidney and liver disorders
- neurological and visual problems
what are examples of fats high in saturated fats
- coconut oil
- butter
- beef tallow
- palm oil
what vegetable oils are rich in monounsaturated fatty acids
- olive oil
- canola oil
- peanut oil
what are some vegetable oils are rich in polyunsaturated fatty acids
sunflower oil
flaxseed oil
etc
what omega will reduce your cholesterol the most
omega 6
what are the two ways that saturated fat increases cholesterol
- decrease LDL receptor activity
- suppress ACAT (rate limiting enzyme of cholesterol esterification)
saturated fat causes ACAT to be suppressed, what does this cause
resulting in greater proportion of cholesterol remaining in the regulatory pool
what does trans fatty acids increase
cholesterol synthesis
what does PUFA (n-6) decrease
cholesterol
what does PUFA (n-3) decrease
TAG
how does PUFA (n-6) decrease cholesterol
- increase LDL receptor activity
- increase CYP7 (rate limiting enzyme in converting cholesterol to bile acids)
how does PUFA (n-3) decrease TAG
decrease lipogenesis and VLDL secretion
increase lipoprotein lipase activity
increase reverse cholesterol transport
what omega is better for anti-inflammatory
omega 3
what % of dietary lipid is phospholipids
5-10% of dietary lipid
examples of information molecules (eicosanoids)
- Prostaglandins
- Thromboxanes
- Leukotrienes
do cis or trans double bonds have higher melting points
trans have higher melting points
example of saturated fat
stearic acid = C18:0
example of monounsaturated fat
oleic acid = C18:1n-9
example of polyunsaturated fat
linoleic acid = C18:2n-6
