Transcript PowerPoint 10 – Polymers & Biochemical Compounds

NOTES 8 – Polymers &
Biochemical Compounds
What is a polymer?

Polymer – a large molecule formed by
linking together many small molecules
(monomers)


Monomers – small molecules that make up
polymers when linked together
Ex. Polyethene (a type of plastic)



The prefix poly means “many”
The suffix ethene is an alkene with the
formula C2H4
Polyethene = “many ethenes”
Natural vs. Man-made Polymers

Natural polymers are large organic
molecules formed by living organisms


Ex. Wood (cellulose), cotton, wool, starch,
protein, DNA
Man-made polymers are created from
natural polymers


Ex. Plastics – flexible and easily molded
Ex. Fibers – form long, thin strands (nylon,
etc.)
Polymer Structure Determines
Properties



Polymer molecules are
like long, thin chains
A piece of plastic is made
of billions of these chains
If the polymer chains are
tangled but not
connected, the polymer
will be flexible
 Ex. Plastic milk jug
(polyethene) - If the
plastic is crushed, it
does not return to its
original shape
Polymer Structure Determines
Properties


If the polymer chains
are connected, or
cross-linked, the
polymer can stretch
and return to its
original shape
Elasticity – the
ability of a polymer to
return to its original
shape when stretched

Ex. Rubber
What are biochemical compounds?

Biochemical compound – a naturally
occurring organic compound







Contains carbon
Has a molecular structure
Produced by living organisms
Essential to life
Some are huge polymers
Remains change over time into fossil fuels
(coal, oil, natural gas)
Ex. Carbohydrates, proteins, DNA, lipids (fats
& oils)
Carbohydrates



Used for cell energy and building material
Produced by plants (photosynthesis)
Can be small molecules


Ex. glucose and fructose (simple sugars)
Can be large polymers


Ex. Starch is a large plant polymer made of
many linked glucose monomers
Ex. Glycogen is a large animal polymer made
of many linked glucose monomers
Did you know?



Cellulose is the main ingredient in plant cell
walls and is the most abundant organic
compound on Earth - plants produce
roughly 100 billion tons of cellulose per
year!
Paper and cotton are almost 100% cellulose
Cows and termites have cellulose-digesting
microorganisms living in their digestive
systems that enable them to break down
cellulose-rich foods like grass (cows) and
wood (termites) – you don’t have any!
Foods That Contain Carbohydrates


Wheat, pasta, bread, rice, potato, vegetables,
fruits, honey
Your body breaks down all carbs into glucose,
which is used by your cells or stored as
glycogen (a polymer) in your liver until it is
needed
Proteins

Large polymers made out of many linked
amino acid monomers







There are 20 unique amino acid monomers
Different amino acid combinations make
different proteins
Make up structures of organisms
Speed up chemical reactions
Act as cell to cell messengers
Ex. Insulin – controls blood glucose levels
Ex. Lactase – digests milk sugar (lactose)
Foods That Contain Proteins



Meat, dairy products, eggs, beans, nuts
When you eat foods that contain proteins, your digestive
system breaks down the proteins into individual amino
acids
Your cells bond the amino acids in a different order to
form whatever protein your body needs
DNA – Deoxyribonucleic Acid






Large polymer made out of many linked
nucleotide monomers
Has double helix structure (twisted ladder)
Found in most living cells
Carries genetic code (protein-building
instructions)
Determines organism characteristics
Is able to be copied exactly and passed
from one generation to the next