Download Carbohydrates

BIOCHEMISTRY

½ cup of CHEX MIX
contains 13 g of carbs = 4%
daily value….
How much more can you have
the rest of the day???
_4_ = 13
100 X
X= 325 g

These spinach imposters contain less than 2 percent of “spinach powder” seasoning. Yum! And the
wraps’ green color? Courtesy of food dyes yellow #5 and blue #1.

When was the last time you saw a flowering field of disodium phosphate? Or how about a fresh
crop of maltodextrin? Didn’t think so. These cheese puffs consist largely of corn, but they’ve been
processed to the point that no 20th-century farmer would ever recognize them as food.

In the short run, food choices make a difference. For example, a diet that’s low in iron—typical
among teenage girls—may result in anemia, which causes paleness and a tired feeling. A teenage
athlete who cuts back on calories to trim down may not have enough energy for peak performance.
And eating more calories than you use often shows up as extra pounds of body fat.

Ask students what snacks they often buy and if they look at the nutrition facts label. For those
students that do look at the label, what do they look for when choosing a snack?

Remember the largest amount of ingredients found in your product are listed on the label first and
the smaller % amounts in the bottom
Carbon
Can form large and complex structures
 Organic Chemistry - study of carbon
componds

Organic vs. Inorganic Compounds

Organic Compounds –
Compounds that contain
carbons.


Lipids, proteins, nucleic
acids, carbohydrates
Inorganic Compounds –
Compounds that do NOT
contain carbon.

Salts, water, oxygen
Macromolecules

Macromolecules – “Giant
molecules” made from smaller
molecules


Formed by a process known as
polymerization, in which large
compounds are built by joining
smaller ones together.
The smaller units, or
monomers, join together to
form polymers.
Organic Compounds

Four groups found in living things are:
1. Carbohydrates
2. Lipids
3. Nucleic Acids
4. Proteins
Carbohydrates (carbo =carbon hydrate = H20)

Compounds made up of carbon,
hydrogen, and oxygen atoms

Ratio of 1 : 2 : 1.
Uses of Carbohydrates

Living things use carbohydrates as:
1. Main
source of energy (starches and sugars)
2. Plants and some animals also use
carbohydrates for structural purposes
Uses of Carbohydrates

Animals

Store excess sugar in the form of glycogen


Plants



Located/made in liver and muscles
Store excess sugar in the form of starch for
energy
Use tough, flexible cellulose fibers to give
them their strength and rigidity
Both

Glucose is main energy source for cells
Classification of Sugars

Monosaccharides – Single
molecules


sugar
Examples: Glucose, Galactose, Fructose
Disaccharides – Double sugar molecules

Examples:




(simple)
Glucose + Fructose = Sucrose
Glucose + Galactose = Lactose
Glucose + Glucose = Maltose
Polysaccharides – More than two
monosaccharide molecules

Examples: Starch, Cellulose, Chitin, Glycogen
Classification of Sugars
Lipids

Common categories of lipids are
1.
2.
3.
4.
5.

Functions:
1.
2.
3.

Fats
Oils
Waxes
Phospholipids
Steroids
Can be used to store energy
Some lipids are important parts of biological
membranes and waterproof coverings
Can serve as chemical messengers (steroids only)
Generally not soluble in water
Structure of Lipids
Made mostly from carbon and hydrogen
and oxygen atoms
 Usually has relatively small amounts of
oxygen
 Glycerol molecule + 3 fatty acids
(Triglycerides)

Steroid (4 rings)
Saturated and Unsaturated Lipids
 Saturated
- If each carbon atom in a
lipid's fatty acid chains is joined to
another carbon atom by a single
bond.



“Saturated” means it has the maximum
possible number of hydrogen atoms
Solid at room temperature
Examples – Cholesterol, butter, chocolate
Saturated and Unsaturated Lipids
 Unsaturated-
If there is at least one
carbon-carbon double bond in a fatty
acid.


Liquid at room
temperature
Examples - Corn oil,
sesame oil, canola oil,
and peanut oil
Protein
Proteins - Macromolecules that contain
nitrogen as well as carbon, hydrogen, and
oxygen.
 Made up of chains of amino acids folded
into complex structures.


Amino Acids - Compounds with an amino
group (−NH2) on one end and a carboxyl
group (−COOH) on the other end.
Amino Acids
There are more than
20 different amino
acids.
 Any amino acid may
be joined to any
other amino acid by
bonding an amino
group to a carboxyl
group by dehydration
synthesis.

*When the length of a polypeptide (chain of aa) is more than ~100
aa the molecule is called a protein*
Amino Acids
There are more than 20 different amino
acids.
 What distinguishes one amino acid from
another is the R-group (functional group)
section of the molecule.

Functions of Proteins

Each protein has a specific
role.
1.
Some proteins control the rate
of reactions and regulate cell
processes.

2.
Some are used to form bones
and muscles and tissues.

3.
Enzymes
Structurally = collagen and keratin
Others transport substances into
or out of cells or help to fight
disease.



Antibodies
Red and White Blood Cells
Transport channels in the cell
membrane
Nucleic Acids


Nucleic acids - Macromolecules
containing hydrogen, oxygen, nitrogen,
carbon, and phosphorus.
Made up of repeating units called
nucleotides

Each nucleotide contains:
1.
2.
3.
5-Carbon Sugar
Phosphate Group
Nitrogenous Base
Nucleic Acids

Function:



Store genetic information &
transmit it to future
offspring (DNA)
Transmit genetic
information/ help make
proteins (RNA)
Two Kinds of Nucleic
Acids:
1.
Ribonucleic acid (RNA)


2.
Contains the sugar ribose
Single stranded
Deoxyribonucleic acid (DNA)

Contains the sugar deoxyribose
Dehydration Synthesis




Dehydration synthesis – A chemical reaction that builds
up molecules by losing water molecules.
Used to put together monomers to build polymers.
 The “dehydration” part is the removal of water
 The “synthesis” part is the joining of the two smaller
compounds to create one larger one
TRICK: There will always be one less water produced than
the number of monomers joining together.
http://www.youtube.com/watch?v=UyDnnD3fMaU
Hydrolysis



Hydrolysis – The rupture of chemical bonds by the
addition of water.
Used to break down polymers into their
monomers.
http://www.goldiesroom.org/Shockwave_Pages/Make%20and%20Brake%20Em.htm
Chemical Reactions

Chemical Reaction - A process that
changes one set of chemicals into another
set of chemicals.

Always involve the breaking of bonds in
reactants and the formation of new bonds in
products.
Chemical Reactions and Water
Molecules cannot react chemically unless they are in
solution, so virtually all chemical reactions in the body
depend upon water’s solvent properties.
 Most abundant inorganic compound in the body (accounts
for 2/3 of body weight).

Chemical Reactions
Reactants - The elements or compounds
that enter into a chemical reaction.
 Products - The elements or compounds
produced by a chemical reaction.

Na + Cl  NaCl
Reactants
Products
Energy in Reactions
Because chemical reactions involve
breaking and forming bonds, they involve
changes in energy.
 Will the chemical reaction occur?


Chemical reactions that release energy often
occur spontaneously.


Energy is released in the form of heat, light, and
sound.
Chemical reactions that absorb energy will not
occur without a source of energy.

Every organism must have a source of energy to
carry out necessary chemical reactions.
Organisms and Energy

Plants


Get their energy by trapping and storing the
energy from sunlight in energy-rich
compounds.
Animals


Get their energy when they consume plants or
other animals.
Release the energy needed to grow tall, to
breathe, or to think through the chemical
reactions that occur when humans metabolize,
or break down, digested food.
Activation Energy

Activation Energy - The
energy that is needed to
get a reaction started.


The peak of each graph
represents the energy
needed for the reaction to
go forward.
The difference between this
required energy and the
energy of the reactants is
the activation energy.
Catalysts

Some chemical reactions that make life
possible are too slow or have activation
energies that are too high to make them
practical for living tissue and cells.

Catalyst - A substance that speeds up the
rate of a chemical reaction by lowering a
reaction’s activation energy.
Enzymes

Enzymes - Proteins that act as biological
catalysts.



Speed up chemical reactions that take place in
cells. (by lowering activation energy)
Very specific, generally catalyzing only one
chemical reaction.
Part of an enzyme's name is usually derived
from the reaction it catalyzes.
How Do Enzymes Work?


Substrates - The reactants of enzyme-catalyzed
reactions.
The Enzyme-Substrate Complex




Enzymes provide a site where reactants can be brought
together to react.
This site reduces the energy needed for reaction.
Each protein has a specific, complex shape.
Active Site – The site on the enzyme where substrates
bind.

The active site and the substrates have complementary
shapes, which is often compared to a lock and key model.
Enzyme Substrate Complex
Active site
Regulation of Enzyme Activity

Enzymes can be affected by any variable
that influences a chemical reaction such
as:
1.
2.
3.
pH
Temperature
Cells contain proteins that help to turn key
enzymes “on” or “off”
Animations to help explain:

http://www.lpscience.fatcow.com/jwanam
aker/animations/Enzyme%20activity.html