Transcript Lecture 01 intro

Mineral Nutrition &
Metabolism
NUTR/POSC 650
NUTR 450
E.D. Harris
[email protected]
Nutrition and Metabolism of Minerals
Objective of course:
Instruction:
To deepen a students understanding of the role
of minerals in living systems. To explore their
multitude of functions. To learn how the chemical
property of a mineral relates to its function in cells
and tissues. To rationalize the consequences of
mineral deficiencies based on their known
functions. To gain some insight into experimental
approaches used to assess minerals in a living
environment
The course will combine formal lectures, research
literature, and interactive discussion. Formal
lecture will cover elements in the syllabus.
Didactic and interactive instruction will involve
questions and discussions of formalized lectures
in an environment where all students are both
instructors and learners. Research literature will
feature outside reading assignments of important
papers in mineral nutrition.
Web Address
http://tamu.edu/classes/eharris/NUTR 650-489/
Lecture slides
Class notes
textbook chapters
old exams
study guides
syllabus
Expectations:
The course will NOT:
The course will:
The student is expected to demonstrate a strong
grasp of the fundamentals of mineral nutrition: to be
able to relate the scope of mineral functions with
chemical properties of minerals; to know how
biological transport, uptake, and cell concentration of
minerals is controlled; to know experimental
approaches to studies of mineral functions.
Require students to memorize mineral RDAs, GRASs
or DRIs for humans or any particular plant or animal
species; to know the amount of a particular mineral in
a food source; to know the toxic properties related to
mineral excesses;
Require students in a practical way to know
determinants of bioavailability of important minerals,
distinguish between macro and trace elements, to
know at least 5 important functions performed by
any one mineral element, and to know the
biochemical bases of at least 3 deficiency signs for
each mineral element.
Student Participation
Each student must give a report to the class on
the topic “my favorite minerals”. The student will
have the opportunity to research two minerals
and give a report on the following:
1.
2.
3.
4.
Name of mineral element
Estimated requirement in humans or animals
Chemical properties most suited to its function
Chemical form most commonly found in a living
system
5. Route of assimilation into body organs
6. Best dietary source
7. Functions performed by the mineral
8. Experimental procedures used to study the
mineral
9. Potential candidates for interaction
10. System or systems most grossly affected by a
deficiency
11. Symptoms of mineral deficiency
12. Further research needed
Attendance:
Grade:
Due to the contribution each student makes to the
overall instruction in the course, attendance will be
mandatory. Students who miss a class must provide
the instructor with a written excuse for the absence.
The absence must conform to what the university
recognizes as a legitimate excused absence. There will
be no opportunities to make up classes. The first class
missed with no excuse will result in a 10 point
deduction. The second 20 and third 30. The fourth will
be a dismissal from the class with a grade of F.
At the end the course, a student who displays an
understanding of minerals at the level of 90% of the
total point will be awarded an A; 80-89% a B, and 7079% a C. A student who shows minimal knowledge
gain will be given a D and no knowledge gain, an F.
The grade will be based on exam scores (70%), report
grades (20%), and class participation in discussion
(10%).
Literature Critique
During the course we will review papers that represent contributions to
the basic literature of mineral nutrition. We will discuss the papers in
class in a Journal Club style atmosphere. This means the instructor will
lead a discussion of the paper’s content and call on students to answer
specific questions or offer opinions. Students will be encourage to think
critically, to weigh evidence, and to agree or disagree with the
conclusions. Each student will then come up with his/hers own “take
home”, which in one sentence, summarizes the contribution of the paper
and stays as a lasting
WHERE TO BEGIN
What is a Biomineral?
Key words in the definition
Chemical element or group of elements, mainly in ionic form
Inorganic, i.e., possessing no carbon in its structure
Classify a Mineral based on Nutrition
Essential to vital functions, only source is the diet
Functions cannot be duplicated by organic nutrients
Two nutritional classifications
based on occurrence
Macro
Micro or Trace
3 Categories based on
Chemistry and appearance
Metal ions
Metalloids
Complexes
2 Categories based on impact
Toxic
Non-toxic
Questions to Ponder
Are minerals essential?
Can we synthesize minerals?
Some are
Some can be
Do minerals function alone or in complexes?
Are minerals bound to proteins?
Both
Some are
Do minerals function with enzymes?
Some do
Do minerals function with hormones?
Some do
Can minerals control genetic expression?
Some can
Can minerals control tissue integrity?
Some can
Are dietary minerals dependent only on animals sources?
No
Discuss the accuracies and inaccuracies of this Web Wisdom
1. Minerals are elements that originate in the Earth and cannot be made by
living organisms.
2. For years the supplement market has been dominated by vitamins, but
vitamins and amino acids are useless without minerals.
3. Minerals are needed to maintain the delicate cellular fluid balance, to form bone
and blood cells, to provide for electrochemical nerve activity, and to regulate muscle
tone and activity (including organ muscles like the heart, stomach, liver, etc.)
4. Minerals that come from plant sources are the best source. After all, humans
like all other animals, were created to eat plants, not soil!
5. In order for minerals to be properly absorbed, they need to be acidic. When we
consume inorganic minerals which are always quite alkaline, the body must attempt
to acidify them for absorption.
Course Syllabus
Introduction
Chemistry
periodic table and valence states
transition metal chemistry
Lewis acids and bases
Biochemistry-Enzymes
metal activated vs metalloenzymes
geometry of metal complexes
Nutrition
Nutritional priorities
Bioavailability
Metal Interactions
Physiology-Absorption and transport
protein dependent
membrane transporters
chaperones
Metals and genetic regulation
Mineral transcription factors
Transacting elements
Studies in yeast
Experimental approaches
Balanced diets
Semipurified diets
Intervention
Criteria
Biomarkers
Isotopes
Symptoms of mineral deficiencies
Minerals and hormones
Mineral-related diseases
Individual Macrominerals
Individual trace minerals
Organization of On-line textbook
Chapter 1. Introduction to Minerals.
a.
b.
c.
d.
e.
f.
Definitions
Minerals as chemicals
Distinction between macro- and microminerals
Historical background
Mineral complexes
Nutritional perspective
Chapter 2. Chemical Properties. I. General
a. Chemical properties befitting function and behavior of minerals
1) Valance
2) Water solubility
3) Oxidation/reduction
4) Coordination geometry
5) Interaction with ligands
Organization of On-line textbook (Page 2)
Chapter 3. Chemical properties. II. Electronic Structure of Minerals
a. Quantum theory of atomic structure
1) ionization and valence
2) Orbital shape
b. 3d transition metals
1) orbital splitting
2) ligand effects
3) high spin/low spin states
c. Application to minerals
Chapter 4. Biochemical properties
a. Biominerals
b. Minerals in pathways
c. Minerals as enzyme cofactors
1) Metalloenzymes vs metal-activated
2) Metalloproteins
d. Biomineralization
e. Zinc as a cofactor
f. Bone
Chapter 4 Biochemical Properties (cont.)
g. Biochemical forms of iron
h. Biochemical forms of copper
i. Selenium and Iodine
Chapter 5. Intestinal Absorption
a. General principles
b. Absorption of macromineral
1. Sodium
2. Potassium
3. Calcium
4. Magnesium and phosphate
c. Absorption of microminerals
1. Iron
2. Zinc
3. Copper
4. Selenium
Chapter 6. Post absorption and assimilation
a. Overall perspective
1) rules governing transport and delivery
b. Membrane penetration
1) simple diffusion
2) facilitated diffusion
3) active transport
4) receptor-mediated endocytosis
c. Intracellular transport
1) intracellular ligands
2) chaperones for copper
d. Bioavailability
1) key organs
3) calculation of
Chapter 7. Nutritional Properties of Minerals
a. Assessing nutritional status
1) balance
2) clinical approaches
3) standards of optimal uptake
b. Assessing mineral status
1) body stores
2) overt response to intake
3) functional assays
4) reversing deficiencies
c. Biomarkers: application and limitations
d. Assessing adequacy and risk of toxicity
1) risk of excess
2) assessing bioavailability