Transcript LE - 2 - Organic Molecules

Elements in Life
• To put it simply, all life contains the same basic
materials. Living organisms are made up of the
following elements with the following percentages:
Elements in Life
• How do we know if something is living? It
contains the elements C and H together. We
call this organic.
• Inorganic molecules do NOT contain carbon
and hydrogen together.
Elements in Life
• Water! Our bodies are 65% water, but water is
inorganic
• Organic molecules can be broken down into 4 main
categories. These substances are needed for life to
grow and function properly.
Proteins
Carbohydrates
Lipids
Nucleic Acids
How Do We Get These ORGANIC
Molecules?
• We eat to take in these substances.
– Food for building materials - proteins
• to make more of us (cells)
• for growth
• for repair
– Food to make energy - carbs
• calories
• to make ATP
Plants don’t need to
eat to get these
molecules. They
make them! Does
anyone know HOW?
Breaking Down and Building Up
• How does the food turn into molecules that run and
build our body?
• The food gets broken down into simple units. Then
those units are used or assembled in our bodies and
turn into something we need!
Monomers and Polymers
We call the building blocks monomers:
The complex units are called polymers:
Breaking it Down
• The food we eat gets broken down into
simple units (monomers). We call this
process digestion.
– We can break it down physically
– We can break it down chemically
Hydrolysis
• Literally means “water – cutting”. Water is
used to break down various polymers.
+
=
Example of Digestion
ATP
ATP
ATP
ATP
ATP
starch
ATP
glucose
ATP
Starch is digested to Glucose
Building it Up
• Once we have these monomers in our
bodies, we use them for various functions.
• Synthesis
– building bigger molecules from smaller
molecules
– building cells & bodies
• repair
• growth
• reproduction
Dehydration Synthesis
• Dehydration = lose water
• Synthesis = put together
-
=
Example of Synthesis
amino acids
protein
 Proteins are synthesized by bonding amino acids
amino acids = building block
protein = polymer
Life Substances
• Now we’ll be talking about these life
substances in detail. Remember, all living
things contain these substances.
• Our bodies contain them, and the food we eat
contains them too…this makes sense since
the food we eat comes from living material as
well.
Life Substances in Detail
Life
Substance
Protein
Carbohydrate
Lipid
Nucleic
Acid
Usually
ends
in...
Monomer
Polymer
Elements
it
Contains
Indicator
Chemical
Structure
What it
Does
Food
Examples
Examples
in Our
Bodies
Unique
Properties
Monomer/Polymer
• Usually ends in –in, or –ine.
• Monomer – Amino Acids
– 20 different kinds of amino acids
• Polymers – Protein, Peptide, Polypeptide
amino amino amino amino amino
acid – acid – acid – acid – acid
About Proteins
• How many amino acids are linked together
to make this protein?
• Is this a dipeptide of a polypeptide?
Elements/Indicator
• Elements: C, H, O. N
• Indicator: Biuret solution
DID YOU KNOW?
It’s the Nitrogen in proteins
that make our urine
YELLOW? The more N, the
greater the color…
Chemical Structure
• The function of a protein depends on its SHAPE.
• Proteins fold into different shapes because of certain
bonds in the amino acids.
• Different shape = different function!
growth
hormone
hemoglobin
pepsin
It’s SHAPE that matters!
• Proteins do their jobs, because
of their shape
• Unfolding a protein destroys its shape
– wrong shape = can’t do its job
– unfolding proteins = “denature”
• temperature
• pH (acidity)
unfolded
“denatured”
folded
What it Does
• What do proteins do?
– many, many functions
• hormones
– signals from one body system to another
– insulin
• movement
– muscle
• immune system
– protect against germs
• enzymes
– help chemical reactions
Examples in Food/Bodies
Body Examples
– muscle
– skin, hair, fingernails,
claws
• collagen, keratin
– pepsin
• digestive enzyme
in stomach
– insulin
• hormone that controls
blood sugar levels
Food Examples
- meat
- beans
- egg
- cheese
Monomer/Polymer
• Usually ends in –ose
• Monomer = simple sugar,
monosaccharide
• Polymer = carbohydrate,
polysaccharide
sugar
sugar
sugar
sugar
sugar
sugar
sugar
sugar
About Carbohydrates
• Looking at the molecules below, identify
the:
– Monosaccharide (glucose)
– Disaccharide
sugar sugar
– Polysaccharide
MONOSACCHARIDE
sugar
sugar
sugar
DISACCHARIDE
sugar
sugar
POLYSACCHARIDE
Elements/Indicator
• Elements: C, H, O
• Indicator:
– Glucose – Benedicts Solution
– Starch – Iodine
Chemical Structure
• Monosaccharides have a simple ring
structure.
• When they are bonded in a chain they
make a polysaccharide.
What it Does
• Function:
- quick energy
• from simple sugars,
like fruits
- energy storage
• from complex carbs,
like starch
- structure
• cell wall in plants
What it Does
Examples in Food/Bodies
• Body Examples • Food Examples
– Glycogen
– Bread
– Glucose
– Fruit
– Cellulose
(plants only)
– Veggies
– Ice Cream
Plants need cellulose! When we eat it,
we can’t digest it.
Digesting Starch vs. Cellulose
starch
easy to
digest
cellulose
hard to
digest
enzyme
enzyme
Cellulose
• Cell walls in plants
– herbivores can digest
cellulose well
– most carnivores cannot
digest cellulose
• that’s why they
eat meat
to get their energy
& nutrients
• cellulose = roughage
– stays undigested
– keeps material
moving in your
intestines
Different Diets of Herbivores
Cow
can digest cellulose well;
no need to eat other sugars
Gorilla
can’t digest cellulose well; must
add another sugar source, like
fruit to diet
Helpful bacteria
• How can cows digest cellulose so well?
– BACTERIA live in their stomachs & help digest
cellulose-rich (grass) meals
Eeeew…
Chewing
cud?
http://www.youtube.com/watch?v=_qf_r5EVP6U
Monomer/Polymer
• Don’t end in anything specific
• Monomer = fatty acid
• Polymer = Lipid
Elements/Indicator
• Elements: C, H, O
• Indicator: Brown
Paper Towel
Chemical Structure
• Very long chains.
Made up of a
“head” and “tail”
• Hydrophobic
“water-hating” tail
• Hydrophilic “waterloving” head
What it Does
• Function:
– energy storage
• very concentrated
• twice the energy as
carbohydrates!
– cell membrane
– cushions organs
– insulates body
• think whale blubber!
Examples in Food/Bodies
• Body Examples • Food Examples
- Hormones
- Fats
- Sex Hormones
- Oils
- estrogen
- Waxes
- testosterone
Saturated fats
• Most animal fats
– solid at room
temperature
• Limit the amount in
your diet
– contributes to heart
disease
– deposits in arteries
Unsaturated fats
• Plant, vegetable & fish fats
– liquid at room
temperature
• the fat molecules
don’t stack tightly
together
• Better choice in your
diet
Saturated vs. Unsaturated
saturated
unsaturated
Other Lipids in Biology
• Cholesterol
– good molecule in cell membranes
– make hormones from it
• including sex hormones
– but too much cholesterol in blood may lead to
heart disease
Other Lipids in Biology
• Cell membranes are made out of lipids
– phospholipids
– heads are on the outside touching water
• “like” water
– tails are on inside away from water
• “scared” of water
– forms a barrier
between the cell
& the outside
http://www.youtube.com/watch?v=NmcLCpXVTrY
Monomer/Polymer
• Ends in –ine or –cil
• Monomer = Nucleotide
• Polymer = Nucleic Acid
nucleotide – nucleotide – nucleotide – nucleotide
Elements/Indicator
• Elements: C, H, O, N, P, S
• Indicator: Everything has DNA, but if
we wanted to compare DNA we can
use Gel Electrophoresis.
Chemical Structure
• Double strand twists into a double helix
– weak bonds between nitrogen bases join the
2 strands
• A pairs with T
– A :: T
• C pairs with G
– C :: G
– the two strands can
separate when our
cells need to make
copies of it
What it Does
• Function:
– genetic material
• stores information
– genes
– blueprint for building proteins
» DNA  RNA  proteins
DNA
• transfers information
– blueprint for new cells
– blueprint for next generation
proteins
Examples in Organisms
Examples in Organisms:
– DNA
• DeoxyriboNucleic Acid
– RNA
• RiboNucleic Acid
Copying DNA
• Replication
– copy DNA
– 2 strands of DNA helix are
complementary
• they are matching
• have one, can build other
• have one, can rebuild the whole
DNA Replication
• Copying DNA
– pairing of the bases
allows each strand to
serve as a pattern for
a new strand
Newly copied
strands of DNA
http://www.youtube.com/watch?v=xZaMi6OhsSU