Chapter 3-2, 3-3 and 49-1
Organic Compounds &
Nutrition
Modern Biology
Pages 52-65, 976-982
Do Now
Respond to the following in
your notebook:
Why do we need to eat food?
What do we get from our food
that is so important? What
would happen to you on the
molecular level if you don’t
eat?
Molecules of Life
Organic Compounds:
• Chemical compounds found in
living things
• All organic compounds contain
the element carbon
• The chemistry of carbon is
the chemistry of life!
Molecules of Life
Why is carbon so special?
Carbon can covalently bond in
different ways to produce many
molecules of very different
shapes and functions!
Molecules of Life
Why do we call sometimes call
molecules of life macromolecules?
Large Carbon compounds are built from
smaller compounds called monomers
Monomers
join together to form the
larger carbon compounds called
Polymers
POLYMERS = MACROMOLECULES
Organic Compounds
Four types of organic
compounds are essential for
life:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids
Four types of organic compounds
essential for life
Carbohydrate
Protein
Nucleic Acid
Lipid
Carbohydrates
Carbohydrates
Carbohydrates are molecules that are
made out of sugar.
These molecules are used for energy
and energy storage. When an organism
needs energy, its cells break down
carbohydrates
Carbohydrates
Made of carbon, hydrogen
and oxygen arranged as a
ring (ex. glucose - C6H12O6)
Forms:
– Monosaccharides
– Disaccharides
– polysaccharides.
Carbohydrates
Functions:
ENERGY
• Primary source of energy:
Only source of energy for the brain
- Stored as starch & glycogen
• Protection: (chitin exoskeleton for
some insects & mollusks); antibody &
cell recognition).
• Structural elements:
• Cell wall of plants (cellulose=“Dietary
Fiber”)
Carbohydrates
Food Sources: fruit, potatoes,
rice, pasta, bread, ice cream
(sweet and squishy foods, grains).
Carbohydrates
Monosaccharides
Building blocks of carbohydrates.
• Aka: simple sugar
• Most common:
– Glucose-made by plants during
photosynthesis. Main source of
energy for cells.
– Fructose-found in fruits, sweetest of
simple sugars.
– Galactose-found in milk, usually in
combination with glucose and fructose.
Carbohydrates
Disaccharides:
• 2 monosaccharides joined together.
• Aka, double sugar.
• Most common:
– Sucrose-found in sugar cane and sugar
beets; made of fructose and glucose.
– Maltose- 2 glucose joined (formed
during the digestion of starch)
– Lactose-found in milk; made of glucose
and galactose.
Polysaccharides:
• 3 or more monosaccharides joined
together.
• Most Common:
– Glycogen - long chain of glucose
–
–
–
Animals store glucose.
Stored in liver and muscles.
Good source of quick energy
– Starch - linked glucose
–
How plants store glucose.
– Cellulose – very long chain of glucose
–
–
Gives strength and rigidity to plant cells
Not digestible.
C
C
Proteins
Proteins
Proteins are large molecules in a cell
that carry out the functions of life.
Proteins contain chains of smaller
molecules called amino acids.
Proteins
Proteins are made of carbon, hydrogen,
oxygen, and nitrogen.
Makes up skin and muscles as well as
enzymes.
Functions:
• Form structural parts of cell.
• Carry other structures (hemoglobin)
• Protection from disease (antibodies)
• Speed up chemical reactions (enzymes)
• Chemical messengers (hormones)
• Control traffic in and out of cell (cell
membrane)
Proteins
Food Sources:
eggs, meat, fish, beans, soy, nuts,
dairy.
**Food supplies the building
blocks (amino acids) that our
body is not able to make.
**Amino acids attained from
food called essential amino acids.
Proteins
Amino Acids
• Building blocks of proteins.
• 20 different amino acids make
ALL proteins.
• All have same basic structure.
– Side chain (“R” group) is how
each is different.
The pink
shaded
area
represents
the “R”
group-how
each is
different.
Proteins
Structure of Proteins
Dipeptide-2 amino acids linked
together.
Polypeptide- long chain of linked
amino acids. All proteins are
polypeptides.
– If temperature is too high, the
bonds may break causing the
protein to untwist (denature). The
protein is then useless.
Before and After!
Science Fact
Some proteins are very
strong. They make up
many different things
such as hair, finger nails,
muscle fibers, spider webs
and feathers.
Proteins
Levels of Structure
• Primary- long chain of amino
acids.
• Secondary- chain spirals
• Tertiary- spiral chain twists on
itself
• Quaternary- several tertiary
bonded together.
Proteins
Enzymes
29
What are Enzymes?
• Enzymes are
Proteins (in the
tertiary and quaternary
structure)
• Act as Catalysts:
– What is a catalyst?
*accelerates a
reaction by lowering
the energy(activation
energy) needed to
start it.
– Not permanently
changed in the
process
30
Enzymes
Enzymes are specific for
what they will catalyze.
• They are Reusable…
• Usually end in –ase
-Sucrase
-Lactase
-Maltase
31
Enzymes
32
Enzymes
Enzyme-Substrate Complex:
Formed when the region of an enzyme
molecule (the active site) binds to the
substrate.
Region of an
enzyme where
the substrate
attaches.
The molecule
upon which an
enzyme acts
Enzyme
33
Enzymes
Enzyme-Substrate Complex:
*Enzymes depend on a physical fit (lock &
key model) between the active site of the
enzyme and the substrate.
*Substrate: what the enzyme binds or acts
on. (i.e. Substrate (milk protein-casein) +
Enzyme (a milk-curdling enzyme produced in
the stomachs of young mammals, rennin) =
milk curd
34
Enzymes
Induced Fit Model:
• Only the exact substrate is capable of
‘inducing’ (causing) the proper alignment of
the active site.
• Only that induced fit will allow the
enzyme to perform its action.
35
What
affects
enzyme
activity?
36
What effects enzyme activity?
Environmental Conditions
1.Extreme Temperature are the most
dangerous
2. Change in pH (most like 6 - 8 pH
near neutral)
3. Ionic concentration (salt ions)
4. Amount of substrate
5. Presence of co-enzyme
6. Presence of an inhibitor
37
What effects enzyme activity?
What are Co-Enzymes?
Co-enzymes - Inorganic substances (i.e.
zinc, iron) and vitamins that are
sometimes needed for proper enzymatic
activity.
• They bind to the enzyme to help it
change to the correct shape
• REMEMBER: Called an Induced Fit:
• A change in the shape of an enzyme’s
active site
• Induced by the substrate
Example: Iron must be present in order for
hemoglobin to pick up oxygen.
What effects enzyme activity?
What are Enzyme Inhibitors:
Competitive inhibitors:
–Chemicals that resemble an enzyme’s
normal substrate and compete with it
for the active site.
–Block an enzymes activity.
Substrate
Enzyme
Competitive inhibitor
39
What effects enzyme activity?
Non-Competitive inhibitors:
• Inhibitors that do not enter the
active site, but bind to another part
of the enzyme causing the enzyme to
change its shape.
Substrate
active site
altered
Enzyme
Noncompetitive
Inhibitor
40
Lipids
Lipids
Lipids are molecules in a cell
that store energy, make up
the cell membrane or make up
hormones.
Lipids are different from
proteins and carbohydrates
because they do not dissolve
in water.
42
Lipids
Made of carbon, hydrogen and oxygen.
Do NOT dissolve in water.
• Function- secondary source of energy,
build cell membranes and other cell
parts, provide insulation, protection.
• Food Sources-olive oil, meat, fish,
butter, cheese, milk, nuts, avocados, nut
oils.
*Most an animal’s lipids are solid
* Most of a plant’s lipids are liquid
43
Lipids
There are two types of lipids:
1. Complex lipids: (made of fatty acids)
1. fats, oils
2. Waxes
3. phospholipids
2. Steroids (made of fused carbon
rings)
44
Lipids
Fatty Acids – unbranched carbon chains
that make up most lipids.
The carboxyl end is hydrophilic, while the rest
of the molecule is hydrophobic
45
Types of Lipids
Complex Lipids - Fats (triglycerides):
• Made of 3 fatty acids and 1 glycerol.
• If solid at room temperature = Fat
• If liquid at room temperature = oil.
46
Types of Lipids
Bad Fats:
Saturated:
• All single bonds
• all carbons are saturated with
hydrogen.
• Solid at room temperature (i.e.
dairy, animal fats, coconut & palm
oils)
• Hydrogenated (man–made saturated
fats = trans fats)
• unsaturated fats made saturated by
adding hydrogen (i.e. margarine)
47
Types of Lipids
Good Fats:
Unsaturated:
• Has double bonds so not all the bonds
are filled with hydrogen
• Liquid at room temperature (ex. olive
oil, flax seed oil)
48
Types of Lipids
49
Other Types of Complex
Lipids
Phospholipids:
• Make the cell membrane.
Wax:
• Waterproof-performs a protective
function.
• In Plants-waxy coating on leaves
prevents water loss.
• In Animals-earwax protects your
ear canals from dirt, dust, etc.
50
Other Types of Lipids
Steroids:
• Four carbon rings.
• Found in hormones, nerve tissue,
venoms, plant poisons
• Example: Cholesterol-needed
for nerve cells and other cells
to function normally.
51
52
Nucleic Acids
53
Nucleic Acids
Nucleic Acids are molecules that
store important information about
characteristics of an organism.
They also play a role in the
production of proteins!
54
Nucleic Acids
2 Types:
1. DNA (deoxyribonucleic
acid)
•Stores information
essential for all cell
activities.
2. RNA (ribonucleic acid)
•Stores and transfers
info. Essential for
making proteins.
55
Nucleic Acids
Nucleic acids are made of
nucleotides.
Three main parts:
1. Phosphate group.
2. Deoxyribose
– a five carbon sugar.
1. Nitrogen base.
56
Nucleic Acids
Nitrogen bases:
•Adenine
•Guanine
•Cytosine
•Thymine
57
Nitrogenous Bases
FYI - The nitrogen
bases for DNA are:
thymine (T), guanine
(G), cytosine (C) and
adenine (A).
DNA base pairing is
highly specific: T pairs
with A (T-A) and G
pairs with C (G-C).
For RNA they are
adenine, guanine,
cytosine and uracil (U).
RNA base pairing is not
as specific, but can be
said to occur like so: U
pairing with A (U-A)
and G pairing with C.
58
Nutrients
59
Six Basic Food Ingredients
1. Carbohydrates
2. Proteins
3. Lipids
4. Vitamins
5. Minerals
6. Water
Four of these NUTRIENTS are organic:
1. Carbohydrate
2. Proteins
3. Lipids
4. Vitamins
60
Six Basic Food Ingredients
Nutritionists
categorize food
into four groups:
1. meat
2. dairy
3. fruits & veggies
4. grains
61
Six Basic Food Ingredients
Carbohydrates:
*provide the body with most of it’s energy
*sugars are quickly converted into usable
energy
-cellulose, an indigestible
polysaccharide, provides fiber that
aids in human digestion
Proteins & Lipids (fats):
*must go through many chemical processes
before the body can obtain energy from
them
62
Six Basic Food Ingredients
Vitamins & Minerals:
*organic and inorganic substances
*must obtain from food you eat
-Vitamins are organic
- Some are fat soluble; others are
water soluble
-Vitamins aid in growth; control chemical
processes that go on in the body (coenzymes)
-Vitamins A, C, and E, for example, are
vitamins your body needs
-Vitamin D is the only vitamin your body
can make
63
Six Basic Food Ingredients
Vitamins & Minerals:
* Minerals are inorganic; don’t contain
carbon
*Minerals help body tissues to function
-Zinc, iron, calcium and phosphorus,
for example, are all minerals your
body needs
64
Six Basic Food Ingredients
Water:
*inorganic substance
*must drink water (optimal 6-8
glasses daily)
-More than half your body weight
is water
-every cell in your body needs
water
- Aids in chemical reactions
-maintains body temperature
- helps get rid of wastes
65
Calories
The energy in
carbohydrates,
proteins and fats
is measure in
calories.
A calorie is a
measure of food
energy.
Most foods
contain nutrition
labels that tell you
the amount of
calories and
certain nutrients
in that food.
66
Calorie Counting
Fat, carbohydrates, and protein are the
only nutrients that contribute calories to
food.
1 gram of fat = 9 calories
1 gram of carbohydrates = 4 calories
1 gram of protein = 4 calories
Add up the calories from these three
nutrients to get the total calories shown
on the label.
Here’s the math:
12 grams of fat x 9 calories per gram =
108 calories
25 grams of carbohydrates x 4 calories
per gram = 100 calories
3 grams of protein x 4 calories per gram =
12 calories
108 + 100 + 12 = 220 calories
67
Calorie Counting
68