Nutrition (EXAM C) Flashcards
What is a carbohydrate?
- macronutrient
- contains carbon, hydrogen and oxygen
- grouped as monosaccharides, disaccharides, polysaccharides
- sugars, starches and dietary fibre
What are monosaccharides?
- simple/single-form of carbohydrates
- glucose, fructose, galactose
- combine to form disaccharides
What are disaccharide?
- 2 monosaccharides come together through a dehydration reaction (i.e. remove water) - stored as fat if not burned off
Glucose + Glucose =
maltose
Glucose + Fructose =
sucrose (table sugar)
Glucose + Galactose =
lactose (milk sugar)
What are polysaccharides?
- long chains glucose molecules
- “complex carbohydrates”
- starch and cellulose (i.e. fiber) - from plants
- glycogen - from animals
What % of calories intake of carbs should you have?
- 55-60% (10% as simple sugars)
- 10% of 2000 cal diet is roughly 300g
What is the glycemic index?
- represents the effect that a particular food product has on the increase in blood glucose
- foods high in refined sugars are high glycemic
(I.e. pure sugar) - foods low in refined sugars (I.e. complex CHO)
are low glycemic
Fates of Blood Glucose:
- energy (brain, kidney, muscle)
- can be converted to liver/muscle glycogen
- stored as fat-when not burnt off
- excreted in urine
What is blood glucose?
- sugar that the bloodstream carries to all cells in the body to supply energy
How much total energy of carbohydrates is stored in the body? (muscle glycogen)
- 12 grams/kg of muscle tissue
- storage can be increased or decreased
- 360 grams or about 1440 calories
What are fats composed off?
- triglycerides, cholesterol, and phospholipids
What is a triglyceride?
- principal form of dietary fat
- composed of glycerol and three fatty acids
What is esterification?
- the process of glycerol binding with fatty acids (3)
- is the reaction of an acid with an alcohol in the presence of a catalyst
What is a saturated fatty acid?
- a type of fat in which the fatty acid chains have all or predominantly single bonds
- chains of C, H, and O that have all C double bonds bound with H+
What is a SCFA?
- short chain fatty acid with fewer than six carbon atoms
- often found in butter or dairy
What is a MCFA?
- medium chain fatty acid is a group of fatty acids with 6 to 12 C atoms obtained from edible fats such as coconut oil
What is a LCFA?
- long chain fatty acid has 14-20 carbon chain
- this can be found in meat products
What is the name of the catalyst that allows a fatty acid and glycerol to combine?
- chemical bond known as ester
- process is called esterification
Do fatty acids vary in degree of saturation?
- yes ma’am.
What is a saturated fat?
- a type of fat containing a high proportion of fatty acid molecules without double bonds, considered to be less healthy in the diet than unsaturated fat.
What is a monounsaturated fat?
- typically liquid at room temperature but start to turn solid when chilled
- lowers total cholesterol and LDL cholesterol levels
- may reduce blood pressure
- may reduce risk of heart disease, stroke, and some cancers
- avocados, olives, nuts
What is a polyunsaturated fat?
- Omega-3 and Omega-6
- O3: reduces blood clotting and inflammation and inhibits abnormal heart rhythms
- can lower blood pressure
- found in fish (3), soybeans (6)
What is linoleic acid?
- polyunsaturated essential fatty acid found mostly in plant oils
- omega-6 fatty acid
Where are alpha-linoleic fatty acids found?
- omega-3
What is linolenic?
- a liquid unsaturated fatty acid
- found in green leafy vegetables, flax, nuts and seafood
- *- two double bonds, last double bond found 6 carbons from omega end
- 18 carbon
What are the two structures of linolenic acid?
- two double bonds, last double bond found 6 carbons from omega end, 18 carbon chain length
- three double bonds, last double bond found 3 carbons from omega end, also 18 carbon chain length
What is cholesterol?
- a waxy substance found in the blood and cells and needs for synthesis of cell membranes, vitamin D, and hormones
- it is not essential in our diet; your liver naturally produces it
- only found in animal products
necessary in the formation of steroid hormones such as testosterone and bile salts
What is emulsification?
- The breakdown of fat globules which allows the enzyme pancreatic lipase to act to digest the fats into fatty acids and glycerol
- bile salts aid in the process
How much cholesterols intake is recommended?
- 500mg < 300mg
What is the borderline recommendation of total cholesterol?
- 200-240
What is the borderline recommendation of HDL?
- 40-60