Nutrients

Living things are made up of non-living
chemicals
 These primarily include carbon (C),
hydrogen (H), oxygen (O) and sometimes
nitrogen (N)
Macromolecules refer to proteins,
carbohydrates, lipids (fats) and nucleic
acids
 Nutrients refer to proteins,
carbohydrates and lipids

Carbohydrates

Primary source of energy for the muscles and
brain
 They are the body’s most important source of
energy because they can be quickly broken down
Make up largest part of most diets
 Only plants and some bacteria and protists
can make their own carbohydrates via
photosynthesis

Carbohydrates

Include: whole grain breads, rice, pasta, fruits
& vegetables
 Bad sources (simple sugars): anything with refined
sugar, ex. candy, soda, pastries, milk chocolate

There are 3 main types of Carbohydrates:
1. Monosaccharides
2. Disaccharides
3. Polysaccharides
1. Monosaccharides

Mono = one, saccharide = sugar
 Exists as a single sugar molecule

Contain C, H, O in the 1:2:1 ratio
 Ex. CH2O
Simple sugars  which are the primary energy
for all cells
Ex. Glucose (C6H12O6)


In all body cells; is used by
mitochondria, to make energy
1. Monosaccharides

Other examples:
 Fructose (sugar in fruit)
○ Sweeter than glucose
 Galactose (sugar in milk)
Sugars end in “ose”
 Deoxyribose (sugar in DNA)
2. Disaccharides

Di = two, saccharide = sugar
 Made up of 2 simple sugar molecules put together
Made via “Dehydration Synthesis”
Ex. Glucose + Glucose = Maltose (+ water)

enzyme
bond forms
disaccharide
***A water (H2O) molecule comes off: hydroxide
(OH) off one glucose and a hydrogen (H) off another
2. Disaccharides

Glucose + Fructose
= Sucrose (table sugar)

Glucose + Galactose
= Lactose (milk sugar)

Comes from sugar canes, sugar beets, sugar
maple trees
3. Polysaccharides

Poly = many, saccharide = sugar
 Many sugar molecules linked in long, branching
chains
 Some have 2000 - 6000 sugar molecules

PLANTS: store excess sugar as starch, the
sugar is broken down when needed by plant
 Cellulose: is a polysaccharide and a structural
component of plant cell walls, it cannot be digested
and used as energy but it is used as fibre
3. Polysaccharides

ANIMALS: store energy as glycogen
 Glycogen: polysaccharide, similar structure to
starch
 Chitin: polysaccharide that forms hard exoskeleton
(external skeleton) in insects and crustaceans
Lipids (fats)
Secondary source of energy but are
an excellent energy storage compound (better
than carbohydrates)
 Contain C, H, O but different ratio
1:2:1
 Difficult to be broken down
 Insulate the body, protect organs and makes
up cell membranes
 Aid in vitamin absorption
(fat-soluble vitamins A, E, K).

3 Types of Lipids
Fats, oils, waxes
 Composed of 1 glycerol molecule and 3 fatty
acids = triglyceride; formed by a dehydration
synthesis reaction
1.
3 Types of Lipids
Fats, oils, waxes
 Saturated:
1.
 single bonds between carbon atoms
 Come from animal fats and are more difficult to be
broken down (solid fats)
 Ex. margarine, salad dressings, peanut butter,
meats, FAST FOOD, milk products etc.
 ***Clogs arteries!!!***
3 Types of Lipids
Fats, oils, waxes
 Unsaturated:
1.
 double bonds between carbon atoms
 Come from plants and are easily broken down
(liquid fats)
 Ex. fish fats, nuts, vegetable spreads, butter
3 Types of Lipids
3 Types of Lipids
Phospholipids
 Similar to triglycerides but one fatty acid is
replaced by a phosphate group (water soluble)
2.
3 Types of Lipids
Phospholipids
 Polar end (hydrophilic-water loving) is soluble
in water; non-polar (hydrophobic-water hating)
ends are not soluble in water
2.
3 Types of Lipids
Phospholipids
 Ex. SOAP: The hydrophobic tail traps the
grease and the hydrophilic head (dissolves in
water) washes it away
2.
IMPORTANT
structure of cell
membranes!!!
3 Types of Lipids
Steroids
 Large multiple-ring structure
 Include cholesterol, testosterone, estrogen
and progesterone
 CHOLESTEROL: starting material for various
hormones and is an important part of animal
cell membranes
3.
 Can also combine with other fats to form blockages
in arteries leads to heart disease and stroke
Proteins
Last resort for energy usage 
only used when body is in starvation mode
 Used to:

 build/repair cell structures (ex. muscles, hair)
 control rates of cellular reactions (=enzymes)
Contain C, H, O, N and sometimes Sulphur (S)
 Made of “building blocks” called amino acids
 there are 20 different amino acids

 The type of protein made depends on the order and
number of amino acids
A closer look at amino acids

It is made of an amino group, an acid group
and an R group
 There are 20 different R groups, which give 20
different amino acids
acid group
amino group
R group
Proteins

Each (of the 20) amino acids is attached to a
transfer RNA (tRNA), that has a codon (3 base
pairs...A,T,G,C)
 The codon has to match up to the base pairs on the
messenger RNA (mRNA)
Proteins

Each (of the 20) amino acids is attached to a
transfer RNA (tRNA), that has a codon (3 base
pairs...A,T,G,C)
 The mRNA is read by a ribosome, a tRNA delivers
an amino acid and the amino acid is added to the
growing protein chain (called a polypeptide)
Proteins

Each (of the 20) amino acids is attached to a
transfer RNA (tRNA), that has a codon (3 base
pairs...A,T,G,C)
 Dipeptide: when two amino acids are formed
Peptide Bond

Amino acids are held together by a peptide
bond, which is formed in a dehydration
synthesis reaction
 These bonds are verystrong and difficult to
break
Denaturation
The structure and function of a protein can be
destroyed by heat (fever), radiation (UV rays)
or pH (acidity) changes
 This changes the shape and folding of the
protein

 A reversible change is called denaturation
 A permanent change is called coagulation
○ Ex. Egg in a frying pan

The 3D shape of a protein is IMPORTANT
 Otherwise it will not function properly!

What are classified as nutrients?
 Carbohydrates, lipids and proteins

Which nutrient is the primary source of energy?
 Carbohydrates

What reaction forms disacchrides and
polysaccharides as well as proteins
 Dehydration synthesis
**Draw a concept map of nutrients**
Dehydration Synthesis & Hydrolysis
1.
2.
Disaccharide Formation/Detachment
Peptide Bond Formation/Detachment
***draw diagrams***
Activity and Homework

Complete the NUTRIENTS worksheet
 It will be a homework check
Read pages 30-42
 Answer the following questions

 Page 36 #1, 3, 4
 Page 39 #1-5
 Page 42 #1-5
 All questions will also be a homework check