Transcript Overview of Metaboli.. - Frozen Crocus Productions

General Overview of Exercise Metabolism
Just about anything you eat is metabolized to carbon dioxide &
water with the concomitant synthesis of ATP to provide the
chemical energy necessary to build and repair cellular components
or to sustain muscle contraction.
An Exercise-Centric View of Metabolism
The ATP generated is used up by muscle contraction and a variety of metabolic reactions
regenerate the ATP; predominantly through 4 basic processes:
1-Myokinase reaction
2-Creatine Phosphokinase reaction
3-Glycolysis (in cytosol)
4-Oxidative Phosphorylation (in mitochondria)
We should not however, view ATP generation for muscle contraction as the only metabolism happening:
metabolism of carbohydrates, lipids, & proteins provides the chemical energy ATP necessary for all normal
cellular functions: maintaining membrane potentials, synthesizing hormones, DNA, neurotransmitters,
membranes & proteins in order to replace the ones damaged by radicals and oxidants; or to grow new muscle
cells to increase strength or to grow new fat cells when we eat too much; proteins (and a whole bunch
more…).
Getting back to the ATP thing, these are some
of the major metabolic pathways for
metabolism:
Glycolysis: produces pyruvate for acetyl CoA
production in mitochondria, produces NADH
(electrons) for ETC in mitochondria, anaerobic
production of ATP
MK & CPK: anaerobic production of ATP
TCA: accepts acetyl-CoA for citrate synthesis,
production of NADH (electrons) & TCAintermediates can be used for synthesis of
lipids, DNA, RNA, many amino acids, etc.
β-oxidation: produces acetyl CoA for TCA
Transamination: produces pyruvate, or acetyl
CoA, or TCA
ETC: electrons from TCA cycle & glycolysis
are “joined” to oxygen to make water & the
production of ATP
Pentose Phosphate Pathway: production of
ribose and NADPH for nucleotide and other
synthesis processes
In many cases, vitamins and minerals play a functional role by being part of the structure of the
proteins and/or enzymes (superoxide dismutase, xanthine oxidase, catalase, alcohol dehydrogenase,
hemoglobin, glutathione peroxidase), or being co-factors (NAD, FAD, FMN, etc.) so various enzymes
can do their job, or being part of functional molecules (ATP, GTP, etc.)
And it is the physical properties of the amino acids within a protein that
determines structure and function. Primary structure of a protein is the order
in which the amino acids are joined together . . .
Secondary
structure refers to
how the amino
acids interact to
produce different
shapes . . .
Tertiary structure
refers to how the
different secondary
structures interact to
produce the threedimensional
structure of the
protein
Leucine Zipper
Zinc-finger
The different kinds of structural shapes in a protein are held
together by a variety of different forces:
Charge interactions - positive and negative amino acids attract
- like charges repel
Disulfide bonds – two sulfur-containing amino acids can
covalently bond:
RC-SH + HS-C-R’ →
2H+ + R-C-S=S-C-R’
Hydrophobic interactions – hydrophobic amino acids will
attract to each other (eg. Leucine)
Multivalent metal coordination – metal ions bonding with
multiple amino acids in a single protein (heme, zinc fingers)
Quaternary structure refers to the
structural interactions between
more than one tertiary structure
Two alpha-heme molecules join to two beta-heme
molecules to produce the protein hemoglobin.
Some quaternary structure interactions alter the function of
a protein.
HSP90
ER
Estrogen receptors can exist in the monomer steroid-binding
form as well as in the dimer DNA binding form – notice the
role of the leucine-zipper motif and the zinc-finger motif
An example of vitamin
and mineral use within the
glycolysis pathway
In addition:
Mg++ must be present for the ATP
(or ADP) to bind
To synthesize ATP molecule in the
first place you need Folic Acid,
Thiamine, Cobalamin, PO4, Zn+,
Cr++, & Mg++
Niacin is a component of NAD+
Some Nutritional Requirements For This Process Include:
Protein synthesis
- requires DNA, RNA, mRNA, GTP . . .
- synthesis enzymes require Cr+?, Mg++, Zn+ to function
and amino acids for structure
Synthesis of DNA, RNA, ATP, GTP . . .
- folic acid, B12, glucose, aa, PO4 (structure)
In order for the metabolic pathways to work, the enzymes (proteins) must be
synthesized in the first place . . .
Enzymes perform chemical reactions of metabolism
- requires (protein) synthesis of enzymes (duh!)
- many enzymes contain minerals as part of their structure
- many enzymes require co-factors which contain vitamins as part of
their structure.
Some Nutritional Requirements For This Process Include:
Protein synthesis
- requires DNA, RNA, mRNA, GTP . . .
- synthesis enzymes require Cr+?, Mg++, Zn+ to function
Synthesis of DNA, RNA, ATP, GTP . . .
- folic acid, B12, glucose, aa, PO4 (structure)
- enzymes for synthesis require Zn+,Cr+?, Mg++, to function
Obviously, in order to ensure that we can
maintain appropriate metabolic functions we
need to have the proper nutrients.
Unfortunately, the
average American diet
Really Sucks . . .
With obvious results,,,
Poor
Poor levels of antioxidant
vitamins
Inadequate function of Antioxidant & Redox Control
Enzymes
Number of Food Servings for Daily Caloric Intakes:
Food Group
Standard
Serving Size
Approximate
Calories /
Serving
~ 2000
kcal
~ 2200
kcal
~ 2500
kcal
~ 2800
kcal
Fruits
0.5 cup
71
5
5
5
5
Vegetables
0.5 cup
38
6
6
6
6
Cold-Water Fish
4 ounces
120
2/wk
2/wk
2/wk
2/wk
(Lean Meats on
remaining days)
3 ounces
120
-
-
-
-
Nuts & Seeds
0.25 cup
240
1
1
1
1
Beans & Legumes
0.5 cup
110
2
3
3
3
Dairy
1.0 cup/2 oz.
86
3
3
3
3
Breads & Cereals
1 slice/1 oz
78
5
6
7
7
Red Wine
4 oz
85
1
1
1
1
110
2
2
3
3
-
-
200
400
Added Fats
1 Tbsp (EVOO)
Discretionary Calories
In order to get the nutrients you need; Ya gotta do this…