2.2:6 Macronutrients Flashcards
What does the turn macronutrients mean?
Food categories that are required in high amounts
Name the dietary macronutrients and how much energy do they provide
Fat 9
Protein 4
Carbohydrates 4
What are lipids poorly soluble/insoluble in?
Water
What are lipids soluble in?
organic solvents
What are the functions of fats?
Fuel and energy stores
Insulation
Protection
Membrane structure
Intra/intercellular signalling - phosphilipids
Substrate for hormones and prostaglandin synthesis - cholesterol
Also: flavour texture palatabolity supply of essential nutrients- absorption of fats-soluble vitamins essential for fatty acids
True/false 90% of dietary fats are triglycerides?
True
What are triglycerides made up of
Glycerol and 3 fatty acids
Describe the terms saturated, monounsaturated, and polyunsaturated
Saturated (no c-c bonds)
Monosaturated ( one double bond)
Polyunsaturated ( more than one double bond)
Where are fats and oils obtained from? Do they contain more unsaturated or saturated FA?
Fats- animals (more saturated)
Oils- plants and fish (more unsaturated)
TRUE/FALSE. Do dietary fats contain a mixture of saturated and unsaturated FAs?
True
True/False. In omega6 first double bond 6 carbons from methyl terminal
In omega3 first double bond 3 carbon from methy terminal
True
Besides fats and oils, what other lipids can be found in diets?
Phospholipids
sterols
plant-phytosterol- inhibits cholesterol uptake
Cholesterol is the substrate of synthesis for what molecules?
Bile acids, steroids hormones, and vitamin D
Does dietary cholesterol have a large influence on blood cholesterol?
No, has little influence because most cholesterol is made within the body. Reducing the amount of cholesterol in the diet will not have much effect on the overall cholesterol in the blood
What dietary sources can cholesterol be found in?
Liver, eggs, shellfish
Does increasing dietary cholesterol decrease the reuptake of biliary cholesterol?
yes
What is cholesterol and TAGs (tryglycerides) transported around the body as and what is it comprised of
Lipoproteins (comprised of lipid and apoproteins)
where does VLDL-TAG rich transport TAG to?
Adipose/muscle
Where does LDL-cholesterol rich molecules transport cholesterol from and to?
from the liver to cells
What does HDL do?
Removes excess cholesterol from peripheral tissue
What is the association with raised LDL-cholesterol and Athleroschlerosis?
Raised LDL-C is taken up by macrophages
This creates foam cells which accumulate in the blood vessel wall
This hardens and creates athleroschlerosis
What does the term essential and non-essensial amino acids mean? Give some examples
Essential- CAnt be made by humans therefore need to obtain AA in diet: Lysine
Semi-essential- Depends on a non-essential AA to be synthesized in the body: tyrosine
Non-essential: can be synthesized by the body- Proline and glycine
What does HBV proteins mean?
High biological value proteins
- All of the essential amino acids in sufficient amounts for protein synthesis eg animal protein
What does LBV proteins mean?
Low biological value- LAck some essental amini acids eg Plant proteins
What macromolecule provides the main source of energy?
Carbohydrates
Where are surplus storesof carbohydrates stored? What is it stored as?
Liver as glycogen
and skeletal muscle
What are sources of carbohydrates?
Sugar
NAme a complex carbohydrate (polysaccharides) and what food sources can they be found in?
starches
Bread, potatoes, rice, pasta, cereals, couscous
What are NSP? What food sources can they be found in?
Non-starch polysacharrides aka fibres
Fruits, veg, whole grains, oats, brown rice, bread, nuts, seeds
What properties do insoluble NSPs have?
Water attracting properties which help soften stools and increase bulk feces
Helps reduce transit time though the GIT
Where are Soluble NSPs fermented in?
colon
How does soluble NSP decrease the reuptake of cholesterol?
They bind to bile salts
What is the danger of a high fibre diet?
Hypocholestrolaemia effects
What is the pharmacological action of NSP?
Acts as a substrate for bacterial fermentation in the colon
Bacteria produce short-chain fatty acids which are absorbed by the colonic mucosa
Bacteria also produce butyric acid which is an important fuel for mucosal cells if the colon
Fecal bulk (insoluble fiber)
What would rapidly increase blood glucose levels?
Simple sugars because they’re easily digested in the
What does the glycaemic index relate to?
the concentration of glucose in the plasma after consumption of foods
What does a low GI indicate?
Break down and absorbed (complex CHO, beans legumes, bran) slowly therefore plasma glucose levels go up slowly
what does a high GL indicate?
Break down and absorption rapidly which is not food for patients with diabetes (simple sugars)
