Flashcards in Carbohydrate Nutrition Deck (48)
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1
what are the three macronutrients
carbohydrates
lipids
proteins
2
what is the nature of carbohydrates
composed of carbon, hydrogen, oxygen
3
what is the CHO formula
(H2O)n
glucose = C6H12O6
4
what are the three classifications of cho
monosaccharides
oligosaccharides
polysaccharides
5
what are monosaccharides
basic unit of carbohydrates
glucose
fructose (converted to glucose in liver)
galactose (converted to glucose in liver)
6
what are oligosaccharides
2-10 monosaccharides bonded chemically (disaccharides)
maltose=glucose+glucose
lactose= glucose+galactose
sucrose = glucose+fructose
7
what are polysaccharides
3-thousands of sugar molecule linkages
starch
fiber=cellulose
glycogen
8
what is starch
storage form in plants
amylose-long and straight
amylopectin-branched
9
what are the two different types of fiber
soluble and insoluble
10
what is glycogen
storage form of polysaccharides in mammalian muscle (branched)
11
what are soluble fiber
attracts water and turns to gel during digestion. this slows digestion
12
where is soluble fiber found
oat bran barley nuts seeds beans lentils peas and some fruits and vegetables (help lower risk of heart disease)
13
what is insoluble fiber
it adds bulk to the stool and spears to help food pass more quickly through the stomach and intestines
14
where is insoluble fiber found
wheat bran vegetables and whole grains
15
what is the daily recommended intake of fiber under 50 years of age
over 50 years
38g for men
25g for women
30g for men
21g for women
16
what is the ratio for water insoluble to soluble fiber
3:1 (water soluble =3)
17
where are carbs stored
liver glycogen (100g)
plasma glycogen (3g)
muscle glycogen (400g)
18
where are fats stored
adipose tissue (12,000g)
intrmuscular tricylglycerols (300g)
plasma FFA (0.4g)
plasma triacylglycerols (4g)
19
what is glycogen
storage carbohydrate in muscle and liver
20
how much glycogen does the body store
how much of that does muscle store
how much of that does liver store
2000kcal
400g
90-100g
21
what is glucogenesis
glycogen synthesis
22
what are the steps of glucogenesis
1) start with glucose. ATP is needed to convert glucose into G-6-P
2) G-6P is enzymatically converted into G-1-P
3) G-1-P is enzymatically converted into (UDP)-glucose
4) (UDP)glucose attaches to one end of an existing glycogen polymer chain. UDP is then released
23
what is
glucogenesis
gluconeogenesis
glycogenolysis
glucogenesis = glycogen synthesis from glucose
(glucose to glycogen)
gluconeogenesis (glucose synthesis largely from structural components of noncarbohydrate nutrients
(protein to glucose)
glycogenolysis = glucose formation from glycogen
(glycogen to glucose)
24
what are the four roles of carbohydrates in the body
energy source
(during high intensity exercise)
protein sparer
glycogen depletion triggers glucose synthesis from amino acids
metabolic primer
CHO catabolism serves as a primer substrate for fat oxidation
fuel for the CNS
nerve cells and red blood cells use glucose for fuel
25
excretion of urea in sweat is a measure of
protein breakdown because the bosy is converting proteins into CHO substrates
26
when is most urea seen
in carbohydrate depleted state
27
what are the 5 sources of carbohydrate metabolism
muscle glycogen
glucose
liver glycogen
lactate
CHO ingestion
28
what affects the use of carbohydrate substrates during exercise
exercise intensity
exercise duration
fed state
trained state
29
how does exercise intensity affect the use of carbohydrate substrates during exercise
muscle glycogen in the major substrate used at exercise intensities greater then 50-60% vo2max followed by blood glucose derived from liver glycogen
30