Introductory Nutrition
Unit Five
- a covalently bonded,
polar molecule
Molecules are said to be
polar if they have slight
opposite charges on either
end
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The slight attraction
between the negative
end of one molecule and
the positive end of
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another results in a…
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- Polarity leads to adhesion and cohesion
-Adhesion and cohesion lead to capillary action and surface tension
- High specific heat leads to temperature stability
- High heat of vaporization leads to
evaporative cooling
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- Spheres of hydration form electrostatic interactions, keeping ions from
interacting with each other
- This characteristic means water has a high degree of solvency and
chemical reactivity
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- Water also ionizes into H+ and OH- which can be incorporated into other
molecules or released from them
Osmosis
Solute - substance that is dissolved in a
medium (solvent)
Solvent - substance (usually liquid) that
dissolves a solute
Solution - mixture of solutes dissolved in
a solvent
Concentration - ratio of solute to solvent
Osmosis
Diffusion - the movement of a substance
from an area of high
concentration to an area of
low concentration
Osmosis - the diffusion of water
- the movement of water to an
area of high solute
concentration
Osmosis
Isotonic solution
*concentration of solutes outside the cell
is equal to the concentration inside the
cell
Hypertonic solution
*concentration of solutes outside the cell
is greater than the concentration inside
the cell
Osmosis
Hypotonic solution
*concentration of solutes outside the cell
is less than the concentration inside
the cell
The selectively permeable character of
the cell membrane functions to maintain
isotonic conditions in the body
Animal Cell Osmosis
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Lysed
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Crenated
Electrolyte Functions
The functions of electrolytes are varied and
important:
+ chemically reactive and
participate in metabolism
+ determine charge difference
across cell membranes
Electrolyte Functions
The functions of electrolytes are varied and
important:
+ powerfully affect the
osmolarity of body fluids and
the body’s water content and
distribution
+ form essential minerals
+ regulate acid/base balance
Electrolyte Concentrations
Extracellular fluids (ECF) are fluids of the body found
outside the cells
Intracellular fluids (ICF) are fluids of the body found
inside the cells (cytoplasm)
Electrolyte Concentrations
HPO43(Lo)
HPO43(Hi)
Na+
(145mEq/L)
Ca2+
Mg2+
(Lo)
Mg2+
(Hi)
(Hi)
Ca2+
(Lo)
K+
(4mEq/L)
K+
(150mEq/L)
Na+
(12mEq/L)
Electrolyte Concentrations
Cl(103mEq/L)
Cl(4mEq/L)
HCO3
(Hi)
HCO3(Lo)
OH-
-
H+
H+
OH-
ICF vs. ECF
ICF
65% of body fluids
Major electrolytes
K+
Mg2+
HPO43-
ECF
35% of body
fluids
Major electrolytes
Na+
Ca2+
Cl-
ICF vs. ECF
10L
26L
Interstitial
Fluids
3.2L
Blood
Plasma
Lymph
40L total body fluid
0.8L
Other
Movement of Water
Fluids are constantly exchanged
between these compartments
Osmosis occurs across capillary
walls and plasma membranes
Movement of Water
The movement of the water from
one compartment to the other is
determined by solute
concentrations
Movement of Water
Fluid
Balance
Balance of body fluids means that fluid
intake should equal fluid output
In addition, the fluid gained or lost must
be added to or taken from the right
compartment (ICF or ECF)
Fluid
Balance
Fluid
Balance
As has been seen, electrolyte
concentrations in the different
compartments must also be stringently
maintained
Electrolytes attract water through
osmosis, therefore a loss of fluids results
in the loss of electrolytes
Fluid
Balance
The three structures that play the major
role in fluid and electrolyte balance are:
* brain (hypothalamus)
* kidneys
* adrenal glands
Regulation of Fluid
Intake
volume of ECF
Decreased
or
Increased
osmolarity of ECF
Increased
volume of ECF
which
decreases
osmolarity of ECF
Hypothalamus
Decrease saliva
Creates thirst
Drink fluids
Hypothala
mic and
Kidney
Regulatio
n of
Fluids and
Electrolyt
Adrenal
Gland
Regulation
of Fluids
and
Electrolyt
Minerals
Minerals can be classified into two
groups:
~major minerals (macrominerals)
>100mg/day
~ trace minerals (microminerals)
<20mg/day
Minerals
Sodium (major mineral)
* chemical symbol - Na
* functions - primary cation of ECF
- maintains fluid balance
- necessary for nerve
impulses and muscle
contractions
Minerals
Sodium (major mineral)
* found naturally in most foods &
as
an additive for taste and
preservation
Minerals
Sodium (major mineral)
* deficiencies lead to muscle
cramps,
fatigue, nausea, vomiting,
dizziness
& confusion
* toxicity leads to hypertension
and
Minerals
Potassium (major mineral)
* chemical symbol - K
* functions - primary cation of ICF
- maintains fluid balance
- necessary for nerve
impulses and muscle
contractions
Minerals
Potassium (major mineral)
* found in most fresh foods,
especially fruits, vegetables and
meat
Minerals
Potassium (major mineral)
* deficiencies lead to muscle
weakness & irregular heart beat
* toxicity leads to muscle
weakness & irregular heart beat
Minerals
Chloride (major mineral)
* chemical symbol - Cl
* functions - major anion of the
ECF
- assists in maintaining
fluid
balance
- necessary for
Minerals
Chloride (major mineral)
* major food source is salt
* deficiencies are rare but lead to
vomiting and dehydration
* toxicity leads to hypertension
and
edema (water retention)
Minerals
Phosphorus (major mineral)
* chemical symbol - P
* functions - major anion of the
ICF
- assists in maintaining
fluid
balance
- necessary for DNA,
RNA
Minerals
Phosphorus (major mineral)
* food sources are high protein
foods
* deficiencies are rare but lead to
dizziness and muscle weakness
* toxicity leads to muscle spasms
and
convulsions
Minerals
Selenium (trace mineral)
* chemical symbol - Se
* functions - antioxidant system
- immune function
- necessary for thyroid
hormone production
Minerals
Selenium (trace mineral)
* food sources are organ meats,
pork,
wheat & rice
* deficiencies lead to heart
disease,
arthritis, muscle wasting &
impaired
Minerals
Copper (trace mineral)
* chemical symbol - Cu
* functions - cofactor (enzyme
activity)
- immune function
Minerals
Copper (trace mineral)
* food sources are liver, legumes,
grains & cereals
* deficiencies lead to anemia and
poor immune response
* toxicity leads to vomiting,
impaired
nerve function & impaired
Minerals
Iron (trace mineral)
* chemical symbol - Fe
* functions - cofactor (enzyme
activity)
- immune function
- hemoglobin formation
Minerals
Iron (trace mineral)
* food sources are liver, red meat,
legumes, leafy greens & seafood
* deficiencies lead to anemia and
poor immune response
* toxicity leads to liver damage &
impaired immunity
Minerals
Zinc (trace mineral)
* chemical symbol - Zn
* functions - cofactor (enzyme
activity)
- DNA & protein
metabolism
- immune function
Minerals
Zinc (trace mineral)
* food sources protein rich foods
* deficiencies lead to hair loss,
diarrhea & poor immune
response
* toxicity leads to diarrhea &
impaired immunity
Minerals
Manganese (trace mineral)
* chemical symbol - Mn
* functions - cofactor (enzyme
activity)
- immune function
Minerals
Manganese (trace mineral)
* food sources are legumes,
grains &
cereals
* deficiencies lead to poor immune
response
* toxicity leads to impaired
immunity
Chapter Nine
Objective Seven
Read the last section in the text (pgs 374379) and able to define, identify and
discuss