Dietary, fat, protein, & carbs Flashcards
What are the 3 dietary macronutrients?
fats
proteins
carbs
What are lipids soluble and poorly soluble in?
soluble in organic solvents
poorly soluble in water
Name the 6 functions of fat
fuel & energy store insulation protection membrane structures intra/intercellular signalling substrate for hormone & prostaglandin synthesis
What are triglycerides made up of?
glycerol and 3 fatty acids
What 3 things can the fatty acid chain of a triglyceride be? and which are double bonded?
saturated (no double bonds)
monounsaturated (1 double bond)
polyunsaturated (more than one double bond)
Which are more unsaturated oils or fats?
oils
What are fats and oils derived from?
fats - animals
oils - fish or plants
Where are the double bonds located in omega 3 & 6?
3 - 1st double bond 3 carbons from methyl terminal
6 “ 6 “
What are sterols precursors to?
bile slats
Where are sterols found?
in animal fats
Why are essential fatty acids needed for humans?
can’t insert double bond between 1st seven carbons of fatty acids and required for prostaglandins and leukotrienes
What is linoleic & a- linoleic and how much is needed to prevent deficiency?
lino - omega 6 (1%)
a- lino - omega 3 (0.2%)
Where is cholesterol found in the body?
cell membranes
What synthesis pathways is cholesterol a substrate for?
bile acids
steroid hormones
vit d
What are cholesterol and triacylglcerides (TAGs) transported around the body as?
lipoproteins
VLDLs are rich in what? and transported to where?
rich in TAGs and transported to adipose/ muscle
LDLs are rich in what and transported from where to what?
rich - cholesterol
transports cholesterol from liver to cells
HDLs do what?
removal of excess cholesterol from peripheral tissues
How does raised LDL cholesterol cause atherosclerosis?
taken up by macrophages to foam cells these accumulate in blood vessel walls
What is surplus carbs stored as and where?
glycogen and in liver
What is NSP?
non starch polysaccharides (fibre)
What do insoluble NSPs do?
attract water, soften stools, increase faeces bulk and reduce transit time in GIT
What do soluble NSPs do?
ferment in colon, blunts postprandial glucose response by slowing digestion, binds to bile salts, decrease cholesterol re-uptake
What are the 3 physiological actions of NSP?
substrate for bacterial fermentation in colon
1) bacteria produce short chain fatty acids absorbed by colonic mucosa
2) bacteria produce butyric acid, important fuel for mucosal cells of colon
3) faecal bulk
What is glycemic index?
relates the concentration of glucose in the plasma after consumption of food
