4. Nutrition: Macromolecules
Nutrition
In general, enzymes
are named according
to the chemical they
act upon followed by
an “ase” ending.
protease proteins
carbohydrase carbohydrates
lipase lipids
Some exceptions: Erepsin, pepsin, and trypsin are
enzymes that digest proteins, and don’t end in “ase”
6. Nutrition:
Nutrition Liver
The LIVER:
• stores and releases
excess glucose
(glycogen and fats)
• produce bile salts
from cholesterol to
break down fat
globules to droplets
in small intestines
easier for lipases to
break down and lacteal
absorption
9. Nutrition:
Nutrition Minerals
Minerals are inorganic
compounds (non-carbon
containing) which the
body needs in small
amounts.
essential for enzyme
activity / cellular function
•
•
consumed through diet
Ex. calcium,
phosphorus, potassium,
iron, zinc
•
10. Nutrition:
Nutrition Minerals
If you are getting enough
minerals through your diet,
should you still take
multivitamins/multiminerals?
No!
Some minerals prevent other
minerals from being
absorbed optimally
11. Nutrition: Vitamins
Nutrition
Vitamins are organic
compounds which the
body needs in small
amounts.
• essential for enzyme
activity / cellular function
• consumed through diet
or produced though
beneficial bacteria
12. Nutrition: Vitamins
Nutrition
2 types:
1) water soluble –
vitamin Bs and C, folic acid
• easily removed from the
body
• easily removed during
cooking
2) fat soluble – vitamin A,
D, E, K
• not easily removed from
body do not need to
consume regularly
13. Nutrition Carbohydrates
Nutrition:
• Main source of energy for
the human body
• Made up of carbon,
hydrogen and oxygen
• Healthy diet has at least
55% of person’s energy
needs fulfilled by
carbohydrates
• Carbohydrates are made
up of either single sugar
molecules or chains
• Example: vegetables,
potatoes, grains
14. Nutrition Carbohydrates
Nutrition:
Monosaccharide
• Single sugar molecule
that can exist in chain
or ring structure
• Examples: Glucose
and fructose
• Glucose: used during
cellular respiration and
provides energy for
physical activity and
cellular processes
16. Nutrition Carbohydrates
Nutrition:
Polysaccharide
• Consist of chains of
monosaccharides
• Example: starch,
chitin, cellullose and
glycogen
• Glycogen: made and
stored in liver and
muscle tissues in
animals (can be
converted to glucose
when needed)
17. Nutrition Fibre
Nutrition:
Fibre is cellulose
We do not have
enzymes to digest
cellulose.
Cellulose passes
through our
digestive system
intact, but sticks to
water and
cholesterol along
the way.
19. Nutrition Proteins
Nutrition:
• Proteins are building
blocks of cells and
perform a wide range
of functions.
• Hormones: chemical
messengers that
coordinate cellular
functions
20. Nutrition Proteins
Nutrition:
Protein structure:
• Made up of chains of amino
acids
• A chain of amino acids is
also known as polypeptide
(joined by peptide bonds)
• Variable in size and shape
• 20 amino acids are used to
build proteins in organisms
- we can only make twelve
- eight has to be obtained
from food and are called
essential amino acids
22. Nutrition Proteins
Nutrition:
Protein in the diet:
• Many animal and plant
sources of protein
• Animal protein has
higher concentration of
protein than plant
• Recommended daily for
14 to 18 years is 0.85g
of protein for each
kilogram of body mass
• Provide energy in small
amount
23. Nutrition:
Nutrition Fats
Fats are made of
fatty acids and
glycerol groups.
Fatty acids have
several chemical
bonds between
hydrogen and carbon
atoms, making them
rich in energy.
1g
1g
1g
1g
fat = 9 Calories
carb = 4 Calories
protein = 4 Calories
alcohol = 7 Calories
24. Nutrition:
Nutrition Fats
Fatty acids and glycerol can form the following combinations:
Triglyceride:
3 fatty acids
+ 1 glycerol
Diglyceride:
2 fatty acids
+ 1 glycerol
Monoglyceride:
1 fatty acid
+ 1 glycerol
25. Nutrition:
Nutrition Fats
There are saturated fats and unsaturated fats:
Saturated fats:
-All fatty acids have
single bonds
-Usually solid at
room temperature
Unsaturated fats:
-Fatty acids have
some double bonds
-Usually liquid at
room temperature
26. Nutrition:
Nutrition Fats
There are saturated fats and unsaturated fats:
Saturated fats:
-All fatty acids have
single bonds
-Usually solid at
room temperature
27. Nutrition:
Nutrition Fats
There are saturated fats and unsaturated fats:
Unsaturated fats:
-Fatty acids have
some double bonds
-Usually liquid at
room temperature
28. Nutrition: Cholesterol
Nutrition
Cholesterol:
-Essential to cell membranes,
steroids, nerve insulation, fat
digestion (bile), and produces
vitamin D
-Body manufactures ~2/3 of
cholesterol required; ~1/3 of
cholesterol acquired through
the diet
32. Nutrition:
Nutrition Regulating Sugars
Regulating blood sugar:
Insulin allows
sugar to enter cells
-lowers blood
sugar levels after a
meal
Glucagon releases
sugar from cells
-raises blood sugar
levels when energy
is required
(between meals)
33. Nutrition:
Nutrition Regulating Sugars
Regulating blood sugar:
The liver stores sugar as
glycogen
-glycogen can easily be
converted back to glucose by
glucagon when blood sugar
levels are too low
-glycogen reserves can be
converted to fat to be stored
in cells
34. Nutrition:
Nutrition Regulating Sugars
Type II diabetes:
Chronic high levels
of blood sugar can
lead to the
overproduction of
insulin.
Over time, the cells
develop insulin
resistance (they
stop responding to
insulin).
Sugar is left in the
bloodstream, which
causes damage to
other tissues.
35. Nutrition Energy requirements
Nutrition:
Factors that affect energy requirements:
• Endothermic vs.
Ectothermic animals
• Size of the animal
• Metabolism
-Catabolism:
breakdown of large
molecules
-Anabolism:
produce large
molecules from
small subunits
• Metabolic Rate
36. Nutrition Metabolic rate
Nutrition:
Metabolic rate:
• Rate at which body
converts stored energy
into working energy
• Depends on various
factors
– Body size
– Physical activity
– Sex
– Age
– Hereditary factors
37. Nutrition Metabolic rate
Nutrition:
Measuring energy:
•Measured in SI unit: Joule (J)
•Energy stored in foods is
measured in kJ
•Calorie is another unit used to
measure amount of energy
- 1 c (calorie with small
c): amount of energy required
to raise temperature of 1g of
water by 1 degree Celsius
-1 C = 1000c or 4180 J
40. Nutrition Bulimia
Nutrition:
Bulimia nervosa
•Eating disorder
characterized by binge
eating and purging
•Bulimics also have
irrational fears of weight
gain and a distorted body
self-perception
•Several cases of bulimia
start out as anorexia
nervosa
