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Nutrients
Chemicals of Life
Carbohydrates, proteins, nucleic acids and lipids are all macromolecules
(large molecules made up of several units).
 They are mostly made up of carbon, oxygen and hydrogen (sometimes
nitrogen)

Carbohydrates

Provides energy for animals

Animals cannot make them by themselves- they must be
ingested

Made of 3 elements and 3 elements only

Carbo = carbon

Hydrate = water (hydrogen + oxygen)

C, H, and O

Are either made up of single sugars or chains of sugars
Monosaccharides
Mono = one
 Monosaccharides are carbohydrates consisting of one
sugar.
 Examples: glucose, fructose
 Many single sugars can be in
either ring form or straight
chain form

Disaccharides

Di = two

Disaccharides are carbohydrates made up of two
monosaccharides (single sugars).

The sugars come together by a dehydration process. In
this process a hydroxyl group (-OH) is removed from one
monosaccharide and a hydrogen (-H) is removed from the
other.

These form the water molecule that is removed from the
two sugars and allows the two to be bonded together- hence
the word dehydration.

Examples: Maltose: sugar used in beer, Sucrose: white sugar
Disaccharides

Dehydration Synthesis of sucrose
Polysaccharides- Complex Carbohydrates

Poly = many

Polysaccharides are carbohydrates
composed of many single sugars.

There are 3 important polysaccharides for
us to remember:



Starch
Cellulose
Glycogen
Polysaccharides- Starch

Some starches contain between 2000 – 6000
glucose molecules

Plants store extra sugar molecules as starch
in the roots and stems until they are needed.

At this time, the plants will break the starch
into single sugar molecules for energy.

Ever hear anyone say, potatoes are starchy?
Polysaccharides- Cellulose

May be the most abundant biological molecule.

Found in cell walls of most plants.

Cannot be digested by humans and is referred to
as fibre.

Fibre aids in the elimination of waste for our
body.

Stay regular!
Polysaccharides- Glycogen

Glycogen is the starch of animals.

Animals store carbohydrates as glycogen
in the liver and muscles.

As glucose levels drop in the blood,
glycogen is converted back into single
glucose units.
Lipids

Used primarily in cell membranes.

Also used as an energy source.

Are hydrophobic = not soluble in water**.




Three Groups:
Fats, oils, waxes - (Fatty acids)
Phospholipids ** Are soluble in water
Steroids (Example: cholesterol)
Fatty Acids
The –COOH group at
the end of each chain is
the acid group, giving the
molecule the fatty “acid”
name

Saturated Fatty Acids contain single bonds
between carbon atoms.

Unsaturated Fatty Acids contain double
bonds between carbon atoms
Fatty Acids

The double bonds in the unsaturated fatty acids
are broken down more easily than single bonds.

Single bonded animal fats are harder for the body
to break down?

Which would you rather in your diet?

However, since animals fats are more stable, they
can be cooked at higher temperatures- reducing
cooking time.
Triglycerides

Fat in the blood used to provide energy to the body

Extra triglycerides are stored in different places to be
used later (hips, belly).

Some triglycerides are made in the body and from
other energy sources such as carbohydrates.

High levels of triglycerides are linked to heart disease.
What causes high triglycerides?
Obesity
 Underactive thyroid
 Kidney disease
 Over eating
 Alcohol abuse
 Medicines (steroids, birth control, beta
blockers)
 How can we lower them??

Cholesterol

A waxy substance produced by the liver and found in
certain foods

They are needed to make vitamin D, hormones, build
cell walls, and create bile

1,000 mgs is made by your liver daily and you consume
about 150 to 250 mgs in the foods you eat

Too much cholesterol can lead heart disease
HDL and LDL

Cholesterol combines with proteins to travel
through the bloodstream

When cholesterol combines with the protein
they form high-density lipoproteins (or
HDL) and low-density lipoproteins (or LDL)

HDL is good cholesterol and LDL is bad
cholesterol
HDL and LDL

LDL is the kind that clogs blood vessels, keeping blood
from flowing through the body the way it should.

HDL removes cholesterol from the blood vessels and
carries it back to the liver
What Causes High LDL
Cholesterol Levels?
Overweight
 Genetics
 Diet
 Age

Normal Levels?
Proteins / Enzymes

Proteins are used by cells to build structures
and are used in chemical activities.

Unlike carbohydrates and fats, proteins are not
used for energy.

Like carbs and fats, proteins are made up of C,
H and O and contain N (nitrogen) and S
(sulfur).
Proteins / Enzymes

Proteins are used to build cell structures
whenever cells are damaged or need repair.

Getting “ripped” at the gym- What does this
mean? Why would you have a protein shake
after a workout?

Every second, cells are constructing millions
of proteins just to create red blood cells!
Proteins / Enzymes

Proteins are composed of amino acids.
Clip

There are 20 different amino acids- the order and
number of them determine the type of protein.
Proteins / Enzymes

Enzymes are proteins that control
chemical reactions including digestion and
cellular respiration.

Lactose intolerant?

There are four steps in the process of an
enzyme at work
Proteins / Enzymes

1. An enzyme and a substrate are in the same area. The
substrate is the biological molecule that the enzyme will work on.

2. The enzyme grabs on to the substrate at a special area called the
active site. Enzymes are very, very specific and don't just grab on
to any molecule. The active site is a specially shaped area of the
enzyme that fits around the substrate.

3. A process called catalysis happens. Catalysis is when the
substrate is changed. It could be broken down or combined with
another molecule to make something new.

4. The enzyme lets go and returns to normal, ready to work on
another molecule of substrate.
Proteins / Enzymes
“Toothpickase” activity
Enzymes Have 5 Important Properties

1. They are always proteins

2. They are specific in their action

3. They are not altered by the reaction

4. They are destroyed by heat

5. They are sensitive to pH