560C Test 1 Flashcards
two classes of vitamin E
Tochopherols
Tocotreinols (trienols)
vitamin E vitamers
alpha, beta, gamma, delta
only this has biological activity and can meet needs of the vitamin E
alpha- tocopherol
sources vitamin E
o Primarily plant foods
o Especially oils
o Sunflower, wheat germ, canola, rich in alpha tocopherol
o Soybean, corn less alpha higher gamma
o Green portions of leafs, - alpha tocopherol
RDA Vitamin E
o RDA 15 mg of RRR alpha-tochopherol, men women and prego. 19mg in lactating
where is vitamin E absorbed
the jejunum by passive diffusion
how do you test for vitamin E
Blood analyses
what is the normal blood plasma for vitamin E
5- 20ug
who is at risk for vitamin E deficiency
including premature infants and those with fat malabsorption disorders like , cystic fibrosis and hepatobilary system disorders, like chronic cholestasis
symptoms of vitamin E deficiency
o Skeletal muscle pain (myopathy) and weakness, Ceroid pigment accumulation, Hemolytic anemia, and degenerative neurological problems (peripheral neuropathy ataxia, loss of vibratory sense, and loss of coordination of limbs
symptoms of vitamin E toxicity
o Mild gastrointestinal problems, nausea, diarrhea and flatulence, inpaired blood coagulation, possible increased severity of respiratory infections and occasional reports of muscle weakness fatigues and double vision. Increased mortality. (over 1000 mg)
what is the TU for vitamin E
1,000 mg
functions of Vitamin E
antioxidant, maintains cell membrane, oxidation protection, helps with age related macular degeneration (cataracts)
vit/min that work with vitamin E
selenium and vitamin C
How does vitamin C help E
C regenerates E
vitamin E interference
high intake E can interfere with other fat soluble vitamins, inhibits absorption and metabolism. impairs vitamin K
vitamin E cell membrane function
improves membrane structure , to enhance cellular glucose uptake
Vit E lipid peroxidation function
suggested to diminish oxidation in those with conditions characterized by lipid peroxidation such as iron toxicity and diabetes.
alpha-tocopherol also protects the fats in low density lipoproteins (LDLs) from oxidation.
where is Vit E stored?
no single organ. mostly in adipose tissue.
vit E function glucose transport
may improve insulin action and glucose disposal
two kinds of vitamin K
o Phylloquinone K1
o Menaquinone K2
sources of K1 (phylloquinone)
From plant sources – green leafy
Oils and margarines
Rapeseed and soybean oil
sources of K2 Menaquinone
bacteria in intestines, animal foods: liver, fermented cheese and soybean
daily value of vit K
80µg
what destroys vit K
Exposure to light and heat
where does K1 absorb
requires no digestion, absorbed from the small intestine, jejunum as part of micelles
where does K2 absorb
Synthesized by some bacteria in lower digestive tract absorbed by passive diffusion from the ileum and colon
Normal blood plasma phylloquninone concentrations
0.15- 1.15 ng/mL (.3-2.5 nmol/L)
where is vit K stored?
cell membranes in several tissues - Lungs, kidneys, bone marrow and adrenal glands
is there limited or large storage cap for vit K?
With limited vitamin K storage capacity, the body recycles vitamin K in the vitamin K oxidation-reduction cycle in order to reuse it multiple times.(More information)
function of Vit K
blood clotting. forms GLA, bone miberlization.
how is vit K best absorbed?
with fat
how do you test for vit K?
- Plasma or serum concentrations of phylloquinone reflect recent intake
- Whole blood clotting times and prothrombin time can identify deficiency
is deficiency likely with vit K?
no
what is the level of Vit K deficiency
.5 ug/L associated
what are signs of of Vit K deficiency
Bleeding (hemorrhage), bone mineral density diminished, increased fractures, CVD, arterial calcification, inflammation, clotting issues
who is most at risk for vit K deficiency
- New born infants
- Chronic antibiotics; destruction of Gi bacteria
- Severe gastrointestinal malabsorptive disorders – cystic fibrosis, obstructive jaundice, Crohn’s, intestinal bypass surgery, chronic pancreatitis, and liver disease
- Elderly
what is the TU of vit k
none established
what are signs of vit k toxicity
no known toxicity from natural forms
vitamins that interfere with vit K
Vitamins A and E antagonize Vitamin K
• Excess of both interfere with vitamin K absorption
• Vitamin E may also inhibit metabolism of MK-4 to phylloquinone and increase hepatic oxidation and excretion of all forms of Vitamin K
who is at risk for vit K deficiency
infants, lack of vit k in milk
results of vit K deficiency in infants
bleeding with in skull
meds that interfere with vit K
warfarin, blood thinners
Glycogenesis
synthesis of glucose
Glycogenolysis
breakdown of glycogen into glucose units
Glycolysis
oxidation of glucose
Gluconeogenesis
production of glucose from noncarbohydrate intermediates
what is insulin
Regulates level of blood glucose during periods of feeding and fasting
what is glycagon
a hormone formed in the pancreas that promotes the breakdown of glycogen to glucose in the liver.
what is GI
o Index – alternative way to classify dietary carbohydrates by their impact on bloo glucose levels caused by ease of digestion and absorption
what is GL
equals the glycemic index times the grams of carbohydrate in a typical portion of food
how is NADH produced
product of the Krebs cycle
• Glucose 6 phosphatase
o Glucose 6-phosphatase is an enzyme that hydrolyzes glucose-6-phosphate, resulting in the creation of a phosphate group and free glucose.
where does glycolysis take place
cytosol
where does Krebs take place
mitochondria
what does Electron transport chain take place
mitochondria
what does gluconeogenesis occur
in liver (kidneys during starvation)
components of saliva
o 99.5% water
o Dissolves food
o Principal enzyme alpha amylase (ptyalin)
Alpha amylase
Originates in salivary glands, mouth
Hydrolyzes starch
volume of stomach full vs empty
empty 50mL (2oz) full 1 - 1.5 L (~37-52 oz)
• Neck (mucus) cells
located close to the surface mucosa, secrete bicarbonate and mucus
• Parietal (oxyntic) cells
secrete hydrochloric acid and intrinsic factor
• Chief cells (peptic or zymogenic cells
secrete pepsinogens
• Enteroendocrine cells
secrete variety of hormones
• Parietal cells
an oxyntic (acid-secreting) cell of the stomach wal
• G cells
stimulate hydrochloric acid release
• Hydrochloric acid
o converting or activation zymogen pepsinogen to from pepsin
o denaturing proteins which results in the destruction of tertiary and secondary protein structure and thereby opens interior bonds to the proteolytic effect of the enzyme pepsin
o releases various nutrients from organic complexes
o acting as bactericide agent, killing many bacteria ingested along with food
what is pepsin
the chief digestive enzyme in the stomach, which breaks down proteins into polypeptides.
CCK
increase intestinal motility
gastrin (GRP)/bombesin
Stimulate gastric secretion
secretin
inhibits gastric secretion
MALT
• Mucosa associated lymphoid tissue
GALT
• Gut associated lymphoid tissue
microfold M cells
important for the induction of efficient immune responses to some mucosal antigens in Peyer’s patches
Dendritic Cells
o Type of macrophage
o Found in GI tract
o Destroy foreign antigens and stimulate lymphocytes to destroy antigens
what are the accessory organs
Pancreas, liver, gallbladder
Pancreas
makes endocrine and exocrine cells
Acinar cells
o The pancreatic acinar cell is the functional unit of the exocrine pancreas. It synthesizes, stores, and secretes digestive enzymes.
what is the function of bile
o Acids and salts act as detergents to emulsify lipids
Breakdown large fat globules into small fat droplets
Help absorb lipids by forming small, spherical cylindrical or disc like complexes called micelles
% of bile reabsorbed by ileum
90%
How long for macros to be absorbed from chyme after in intestine
Carbohydrates, proteins and fats absorb within 30 min after chyme reached small intestine
Which hormones involved in suppression and satiety
leptin,
what hormone stimulates apatite
Ghrelin
active transport
the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.
Passive transport
is a movement of biochemicals and other atomic or molecular substances across cell membranes. Unlike active transport, it does not require an input of chemical energy, being driven by the growth of entropy of the system.
