Final exam lecture 1 Flashcards
excess carbohydrates are converted into
glycogen and triacylglycerol
simple carbohydrates divided into
mono and di saccharides
Monosaccarides example
glucose, fructose, galactose
disaccharide example
sucrose, lactose maltose
in what form are complex carbphydrates stored in animals?
In plants?
glycogen in animals and starch and fiber in plants
most abundant carbphydrate on earth?
cellulose
glucose is also called
dextrose
imoprtant carbohydrate
glucose
Where are glicose and fructose usually found
Glucose is found as a part of a disaccharide or starch and fructose is found in fruits and vegetables.
Does fructose cause an increase of blood glucose? What about blood lipids
Fructose does not cause a great rise in blood glucose as other sugars. Causes an increase in blood lipids
what does a-amylase do? where is it?
hydrolyzes starch and glycogen to maltase and maltotriose.
exists in saliva and pancreatic juice.
Name some enzymes on the luminal surface of small intestine and what they do
Maltase (a-glycosidase): maltose and maltotriose converted to glucose
sucrase- converts sucrose to glucose and fructose
Lactase- converts lactose to glucose and galactose
T/F only monosaccharides are absorbed in the body
True
how do bacterial contribute to digestion of carbohydrate
indigestible carbs comverted to monosaccharides by bacterial enzymes
What is the glycemic index
Measure of how quickly individual foods will raise blood glucose level
Rank common foods interms of Decreasing glycemic index
Pure glucose- 100
potato
bread
ice cream
beans
name 3 types of dietary fibers and use of fibers, common sources
Cellulose- cereals, increases stool bulk and decreases intestinal transit time
Lignin- woody part of vegetable, binds cholesterol and carcinogens
pectin- fruits, decreases rate of sufgar uptake and decreases serum cgolesterol
Which fiber is the inly soluble one
pectin
use of lipids in the diet? most predominant lipid in diet?
provide satiety, carriers for fat soluble vitamins
triacylglycerol is >90% of dietary fat
Name essential fatty acids
w3 and w6
Give examples of w3 omega fatty acids
a- linoleic acid (18:3)
eicosapentaenoic acid (EPA) (20:5) and docosahexaenoic (DHA) (22:6)
give examples of w 6 fatty acids
linoleic acid (18:2)
arachidonic acid (20:4) in meat and fish
what is the use of essential fatty acids like w3 and w6
used to synthesize eicosanoids in the body
How does the ratio of w3 to w6 affect the human body
We want the ratio to be higher (i.e we want a higher ratio of w3) due to its anti inflammatory uses.
most unsaturated fatty acids found in nature have_____ double bond
Cis
hydrogenation process to convert unsaturates fatty acids to saturated fatty acids produces____________ as byproducts
trans fatty acids
trans vs cis which one has a higher MP
trans fatty acids have a higher mp than cis formation
is trans or cis worse for heart disease
trans
explain the digestion of fat
fat needs to be solubilized by bile acid
gastric and pancreatic lipases hydrolyze triacylglycerol to fatty acids and monoacylglycerol
esterases hydrolyze monoacylglycerol and cholesterol ester
Explain the utilization of lipids
small intestine cells absorb all the fatty acid and glycerol. They make their own triacylglycerol again (resynthesize) and release it into the lymph system (not blood stream)
Are triacylglycerols directly released into blood stream?
No. chylomicrons lipoprotein is the solubilized version of triacylglycerols, deliver lipid to peripheral tissues directly.
muscles uses _____ as an energy source
fat
does the rbain use fat as an energy source?
No
composition of the body based on percentage
water-65%
protein-20%
fat=12%
other-3%
what are some roles of dietary proteins
essential structural components
enzymes, hormones, plasma, antibodies
what are glucogenic and ketogenic aa converted to?
glucogenic-glucose,
ketogenic aa- keto acid/fatty acid
protein is eventually converted to________in adipose tissue
triacylglycerol
how is a negative nitrogen balance caused?
inadequate dietary intake of protein ,trauma or illness
when do we see positive nitrogen balance
growing children, pregnant women, adults recovering from illness.
what is an essential aa
aa that can not be synthesized by the body.
What are the 3 mechanisms of digestions of proteins
Gastric digestion
peptidases at luminal surafce
intracellular peptidases
How does gastric digestion breakdown proteins
Low PH denatures proteins
pepsin enzyme
how do peptidases at the luminal surface digest proteins
Brush borders on luminal surface rich in peptidases.
what is celiac disease
caused by exposure to gluten. (autoimmune disorder)
lining of small intestine is inflamed and damaged
energy content of carbohydrate, protein, fat and alcohol
carbohydrate 4kcal/g
fat- 9kcal/g
protein- 4kcal/g
alcohol- 7kcal/g
excess energy is stored mostly as
fat in adipose tissue
glycogen in the lliver maintains
blood glucose levels
what happens in body during well-fed state
insulin release,
glycolysis
glycogen synthesis
catabolism of aa
fatty acid synthesis
no gluconeogenesis
What happens during early fasting state
glucagon release from liver
glycogen breakdown
gluconeogenesis
What happens during fasting state
protein is used as a major source of nitrogen
lipolysis of adipose tissue
ketogenesis
reduced thyroid hormones
daily BMR drops by 25%
what happens if glucoe concebntration is less than 27 mg/dl
coma and death
what does hyoerglycemia lead to
dehydration, hyperglycemia, coma, complication of diabetes
what does the brain use as energy
glucose
energy usages of brain?
100-120 g of glucose per day
uses 15-20% of the total oxygen
constant energy needed
energy storage of brain
no energy storage
brain does not use fat
What deficiencies are marasmus and kwashiorkor
marasmus is inadequate intake of both protein and energy, thin waisted appearance
kwashiorkor happens due to inadequate intake of protein with adequate energy intake . They have a deceptive plump appearance due to edema
Acronyms for EAR, RDA, AI and UL
recommended dietary allowance
estimated average requirement
Adequate intake
tolerable upper intake levels
As long as you take less than______, you will not experience toxicity
UL
Maximum level of daily intake without health risk
UL
what do we use when scientific evidence is inadequate to set an EAR
AI
relationship between RDA and EAR
RDA is two standard deviations above EAR.
RDA is sufficient to meet needs of 97%-98% of healthy individuals while EAR is 50%
Fat soluble vitamins
A, D, E, K
water soluble vitamins
B and C
name macrominerals and trace minerals
Macro- Ca2+, Mg 2+
trace- Fe, I, Zn, Cu, Se
what are vitamins
Organic cpds essential in the diet to promote and regulate body functions
which vitamins are still referred to by numbers
B6 and B12
Vitamins are grouped into _____ and ______
fat soluble and water soluble
water soluble or fat soluble causes more toxicity
Fat soluble. This is because fat soluble vitamins are stored.
