Download NUTRIENT CHEMISTRY

NUTRIENT CHEMISTRY
You are what you eat (with a few hundred chemical reactions
in between).
NUTRIENTS
Nutritive chemicals allow burning in your body.
OK, actually it’s oxidation - very slow burning.
OK, OK, actually it’s called metabolism - you’re oxidizing
bio-chemicals.
The goal is to release energy to be used for heat and motion.
This energy is measured in calories.
BIOLOGICAL FUEL
Your body burns glucose, a single-ring sugar.
It can get glucose from other sugars (fructose, lactose,
sucrose, etc.)
It can get glucose from starches
Sugars, starches, cellulose and fiber are all carbohydrates
BIOFUEL STORAGE
Fats are a way for your body to store energy if it has too
many sugars and starches to use immediately.
Your body stores enough glucose (and glycogen) to run 20
miles, bicycle 60 miles... then you run out and start burning
fats.
You have a fixed number of fat cells, they grow and shrink
with fat as needed.
FATS AND OILS
Fatty acids are the building blocks of fats, oils and waxes.
They are collections of long chains of carbon, hydrogen and
oxygen.
Since they are acids they can react in a number of ways with
other chemicals.
If they have as many hydrogens
bonded to the carbons as they can, they
are “saturated” fats.
For scale, 1 lb of butter is 1 lb of animal fat.
PROTEINS
Can be structural (hair, nails, collagen, cartilage, etc... the
materials)
Can be functional enzymes (that make other things - the
machines that make the parts of living things)
They are made of amino acids
DNA codes for RNA that codes for Amino Acids
Protein to amino acid is digestion
Amino acid to protein is synthesis
NON-CALORIC
NUTRIENTS
Water! You use or produce water in many bio-chemical
reactions.
Minerals - nerves need Calcium, Sodium, blood needs Iron,
DNA needs Phosphorus, etc.
Vitamins - VITal chemicals, originally thought to be
AMINes, are used by enzymes to complete reactions.
BUILDING BLOCKS
Obviously you don’t eat chicken wings and get chicken meat
protein taking the place of your hair or nails (eeeeewww!).
Protein is broken down into amino acids and then used to
create the proteins you need.
Fats and oils are broken down into fatty acids and then used
to make the fats used by your body to store energy.
Carbohydrates are broken down into simple sugars and then
used to make other sugars or burned as fuel.
These are the pathways that link
the most common biochemicals.
Do not study this. Appreciate it.
CALORIC NUTRIENTS
Generate heat for reactions and energy for motion,
measured in calories.
1 food Calorie is the amount of heat needed to rise the
temperature of 1 liter of water by 1°C.
Carbohydrates can create 4 calories for every gram
Proteins can create 4 calories for every gram
Fats can create 9 calories for every gram
CALORIC NEEDS AND
USES
A human needs 15 food calories per pound of body weight
every day just to function.
So a 100 lb person needs 100 x 15 = 1,500 calories per day to
stay the same weight.
Eat more, and your body will store the extra as weight.
Eat less and your body will burn the stored weight.
ADDING OR LOSING?
You need 3,600 food calories to create a pound of body
weight.
Eat 3,600 more calories than you need and you gain a
pound.
Spend 3,600 more calories than you need and you lose a
pound.
SPENDING CALORIES
IN EXERCISE
If you bicycle 15 miles per hour and weigh 10 lbs, you burn
600 calories in an hour. Do that 6 days a week and don’t
change your diet, and you will lose 6 x 600 = 3,600 calories
per week. That’s the amount in 1 pound of body weight.
In the Tour de France, cyclists burn about 1,200 calories per
hour, four hours per day for 21 days. That’s 100,800
calories, or the equivalent of losing 28 lbs of body weight, or
eating 373 jelly doughnuts! (of course they eat more every
day and their weight stays the same).
WHAT’S IT WORTH?
So what’s the effect of eating - say - just one more slice of
bread than you need every day?
Most bread is about 100 calories per slice. If you eat one of
those a day more than you need, for a year, that’s 365 x 100
= 36,500 calories. Since 3,600 calories create a pound of
body weight, that’s 36,500 / 3,600 or 10 lbs of body weight.
Healthy nutrition includes balancing food intake and energy
burned through exercise.