Transcript Powerpoint

The most important biological compounds are polymers
Polymers (poly = many)
 The polymers are: proteins, carbohydrates, lipids (fats),
and nucleic acids (DNA/RNA).
 A polymer is made up of a chain of many
monomers linked together
MONOMERS (mono = one)
Monomers are: amino acids, sugars, fatty acids, and
nucleotides.
These are made (dehydration synthesis) or broken
down (hydrolysis) over and over in living cells.
macromolecules
Large polymers are also called _______________
Macromolecules are formed by
joining monomers usually
_________________,
by reactions involving the loss
of water =
DEHYDRATION SYNTHESIS
________________________.
____________
MONOMERS are
joined together
during dehydration
synthesis.
Chains of monomers
are called POLYMERS
_________
Note: enzymes that
speed up dehydration
synthesis reactions
are called
dehydrogenases
_____________.
HYDROLYSIS
The breaking of a polymer into units is ______________
(i.e. done by adding water to polymer).
Note: enzymes that
speed up hydrolysis
reactions are called
hydrolases
__________
http://science.nhmccd.edu/biol/dehydrat/dehydrat.html
Monomers (sub units)
Polymers
Polymers
a)
b)
c)
d)
Polymers
a) Carbohydrates
b)
c)
d)
Polymers
a) Carbohydrates
b)
c)
d)
Hydrolysis
Polymers
a) Carbohydrates
b)
c)
d)
Hydrolysis
H2 O &
Energy
Polymers
a) Carbohydrates
b)
c)
d)
Hydrolysis
Monomers
a)
b)
c)
d)
H2 O &
Energy
Polymers
a) Carbohydrates
b)
c)
d)
Hydrolysis
Monomers
a) Simple sugars
b)
c)
d)
H2 O &
Energy
Polymers
a) Carbohydrates
b)
c)
d)
Hydrolysis
Monomers
a) Simple sugars
b)
c)
d)
H2 O &
Energy
Polymers
a) Carbohydrates
b)
c)
d)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b)
c)
d)
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b)
c)
d)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b)
c)
d)
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c)
d)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b)
c)
d)
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c)
d)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b) Amino Acids
c)
d)
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b) Amino Acids
c)
d)
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b) Amino Acids
c) Fatty Acids & Glycerol
d)
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d) DNA/RNA (nucleic acids)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b) Amino Acids
c) Fatty Acids & Glycerol
d)
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d) DNA/RNA (nucleic acids)
Dehydration
Synthesis
Hydrolysis
Monomers
a) Simple sugars
b) Amino Acids
c) Fatty Acids & Glycerol
d) Nucleotides
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d) DNA/RNA (nucleic acids)
These reactions require:
Dehydration
Synthesis
1.
Hydrolysis
Monomers
a) Simple sugars
b) Amino Acids
c) Fatty Acids & Glycerol
d) Nucleotides
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d) DNA/RNA (nucleic acids)
These reactions require:
Dehydration
Synthesis
1. ATP energy
Hydrolysis
Monomers
a) Simple sugars
b) Amino Acids
c) Fatty Acids & Glycerol
d) Nucleotides
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d) DNA/RNA (nucleic acids)
These reactions require:
Dehydration
Synthesis
1. ATP energy
2. Water
Monomers
a) Simple sugars
b) Amino Acids
c) Fatty Acids & Glycerol
d) Nucleotides
Hydrolysis
H2 O &
Energy
H2 O &
Energy
Polymers
a) Carbohydrates
b) Proteins
c) Lipids (fats)
d) DNA/RNA (nucleic acids)
These reactions require:
Dehydration
Synthesis
1. ATP energy
2. Water
Hydrolysis
3. Enzymes
Monomers
a) Simple sugars
b) Amino Acids
c) Fatty Acids & Glycerol
d) Nucleotides
H2 O &
Energy
Where does the name come from?
Hydrated Carbons: (CH20)n
Carbohydrates have the empirical formula of (CH20)n where
n = the # of times the chain is repeated.
The carbons, hydrogens and oxygens are found in the ratio
of 1:2:1 and are made up of a repeating chain of sugars.
(CH20)3 = C3H603
(CH20)6 = C6H1206
Sugars are also known as saccarides.
Carbohydrates usually end in ‘ose’.
Can you think of any examples?
The basic sugar molecule is GLUCOSE: C6 H12 O6.
Glucose has a ring structure.
Other monosaccharides include fructose, ribose, deoxyribose
6 sided =
HEXOSE
5 sided =
PENTOSE
C6 H12 O6
C6 H12 O6
When two sugars bind together via DEHYDRATION
SYNTHESIS a disaccharide is formed.
glucose + glucose forms the sugar maltose
glucose + fructose forms the sugar sucrose
galactose + glucose forms the sugar lactose
When many sugars bind together via dehydration synthesis
four types of polysaccharides may be formed:
• Starch
• Glycogen
• Cellulose
• Chitin
•
The cell walls of plants are made of cellulose
•
They are long chains of glucose molecules with no
side chains.
•
The linkage between the Carbon atoms of the sugars
is different than starch and glycogen
•
No mammal can break this bond
•
5. This is why we cannot digest cellulose = FIBRE.
• Plants store their energy as starch
• Starch is made up of many glucose molecules linked
together
• Starch has few side chains
•
Animals store their energy (extra glucose) as
glycogen
• We store glycogen in our liver and muscles
• Glycogen is made up of many glucose molecules
linked together
•
Glycogen has many side chains
•
Made by animals and fungi
•
Long glucose chains linked with
covalent bonds.
•
Very strong
•
Makes structures like exo-skeletons, fingernails,
claws, and beaks
1. Energy: when the bonds between Carbon atoms
are broken, the energy released can be used by
cells.
Carbohydrates are the primary
energy molecules for all life.
2. Structural: Cellulose is the
major structural compound in
plants (is used in the cell wall).
Lipids are made up of the elements C,H,O but in no set
ratio.
Lipids are large molecules that are insoluble in water.
Synthesis of a FAT animation:
http://www2.nl.edu/jste/lipids.htm
1. Composed of 3 fatty acids
bonded to 1 glycerol.
2. Fatty acids contain a long
chain of 16-18 Carbons
with an acid end.
3. Glycerol is a small 3
Carbon chain with 3
alcohol (OH) groups
4. These two molecules bind
together via dehydration
synthesis
1. Saturated fats:
There are no double bonds in the carbon chains of the
fatty acids.
The carbons are filled with hydrogens.
Unhealthy.
They mostly come from animals.
Become solid at room temperature.
Examples: lard, butter, animal fats…
2. Unsaturated fats:
There are one (monounsaturated) or more
double bonds (polyunsaturated).
Mostly come from plants.
They are liquid at room temperature.
Healthy
Examples: olive oil, corn oil, palm oil…
Are used to make up the two
layered cell membrane of all cells.
In phospholipids, the third fatty
acid group of a triglyceride is
replaced by an inorganic
phosphate group (PO43-).
This creates a polar end:
The phosphate end is water soluble (hydrophilic)
The fatty acid is not water soluble (hydrophobic)
hydrophilic
hydrophobic
Steroids structurally look very different
from lipids, but are also water
insoluble.
They are made up of 4 Carbon ring
molecules fused together.
Examples: testosterone, estrogen,
cholesterol, and vitamin D.
Used as sex hormones
1. Long term storage for energy (more efficient
spacewise than glycogen or starch).
2. Insulation and protection in animals
3. Making some hormones (steroids)
4. Structure of cell membranes.
Without lipids, we would have no cells.
• Found in fish and leafy vegetables
• Other foods are now offering omega-3’s
(eggs, cereals, margarine…)
• Help to reduce cancer
• Helps with vision
• Helps us think better
Scientific evidence has shown
that dietary saturated and
trans fats can increase your
risk of developing heart
disease.
1. Proteins are made up of the elements C,H,O, and N (but
in no set ratio).
2. Proteins are chains of Amino Acids (usually 75 or more)
that bond together via dehydration synthesis.
3. 40% of the average human body is made up of protein.
1. The building blocks of Proteins are amino acids.
2. There are three parts to an amino acids:
1. Amino Group (NH2 or NH3+) acts as a base (accepts
H+)
2. Carboxyl Group (COOH or COO-) acts as an acid
(donates H+)
3. R Group: there are 20
different possible R groups
Amino acids bond together via dehydration synthesis.
The amino acids bind together
with a peptide bond.
The PEPTIDE bond is formed
between C and N and one water
is lost (dehydration synthesis).
When the original two amino
acids form the beginning of the
chain (with one peptide bond) it
is called a DIPEPTIDE.
Then the chain grows to become a TRIPEPTIDE.
Ultimately you end up with
a POLYPEPTIDE (which
can have anywhere
between 30 and 30,000
amino acids).
Another name for a
polypeptide is protein.
Every protein is different because the ORDER of amino
acids is different.
The chains come together differently due to the order of
the different R groups and how they bond together.
This structural difference also makes the polypeptides
(proteins) functionally different.
This is the first level of how
proteins are formed.
It is simply the order of amino acids joined together with
peptide bonds.
It is the amino acid sequence that determines the nature and
chemistry of the protein.
If you change the order of amino acids, the protein may not be
able to do its job.
This is the second step in the
formation of a protein.
When a peptide bond is formed, a double bonded oxygen is left
over, which is partially negative (the carboxyl group: COO-).
It is attracted to the positive NH3+ amino group from other amino
acids in the chain.
This attraction forms a HYDROGEN BOND.
This causes the chain to twist into either a spiral called an alpha
helix or a beta pleated sheet.
The next interactions take
place between the R groups.
Some R groups are reactive and will interact with other reactive
R groups in the chain. These are the amino acids that are either
charged or that have a sulphur atom.
The interactions ( + and – attractions and S-S bridges) will fold
the molecule over into a highly specific 3-dimensional shape.
It is the 3-D shape that will determine the protein’s job or role in
the body.
The last level in protein formation is not seen in all proteins.
However, some proteins are actually 2 or more molecules
joined to form a functional protein. They are held together with
an ionic bond.
Two examples:
Insulin has 2 subunits
Hemoglobin has 4 subunits.
Peptide Bonds
Hydrogen Bonds
Interactions between R
groups
Ionic Bonds
The final shape of a protein (its tertiary or quaternary structure) is very
specific and enables it to do its job/function.
Any change in a proteins’ shape will affect its function.
Denaturation is when a protein's tertiary structure is lost.
This happens when the
bonds between the R
groups are broken.
When a protein is
denatured, the protein can’t
do its job and becomes
useless.
How can this happen? There are three common ways:
1. Temperature:
High temperatures affect the weak Hydrogen bonds and
can distort or break them, thus changing the structural
shape.
A slight increase in temperature an
cause a reversible change (ie: fever).
A high temperature increase can
cause an irreversible change
(ie: cooking an egg).
How can this happen? There are three common ways:
2. Chemicals:
Heavy metals such as lead and mercury
are large atoms that are attracted the R
groups of amino acids.
They bond to the R group and distort
the protein’s shape.
This is usually irreversible (they usually
don’t want to ‘let go’).
How can this happen? There are three common ways:
3. pH:
As some of the R groups are acids and some are bases,
every protein (enzyme) has a preferred pH.
Any change in pH causes a
change in the acid-base R
group interactions and this will
change the shape of the protein.
1. Structural: proteins help make up all structures in living things
Actin & Myosin: muscle
proteins
Keratin: nails, hair,
horns, feathers
Collagen: bones, teeth, cartilage, tendon,
ligament, blood vessels, skin matrix
2. Functional: other proteins help us to keep our bodies
functioning properly and to digest our food.
Enzymes:
are proteins that
are catalysts which speed up
reactions and control all cell
activities.
Hemoglobin
3. Food Source: once we have used up all of our carbohydrates
and fats, proteins will be used for energy.
Proteins are worth the least amount of
energy per gram.
Anorexia and Bolimia
Nucleic acids are acidic molecules that are found in the
nucleus of cells.
There are two types, both of which are very LARGE.
1. DNA: Deoxyribonucleic Acid
2. RNA: Ribonucleic Acid
All nucleic acids are composed of units called NUCLEOTIDES,
which are composed of three sub-molecules:
1. Pentose Sugar (ribose or deoxyribose)
2. Phosphate
3. Nitrogen Base (purine or pyrimidine)
They are formed by
joining their subunits
together via dehydration
synthesis (nucleotide +
nucleotide … = nucleic
acid).
This is quite a complex
process to which we will
devote an entire unit to.
Adenine and Guanine
Have two rings
Found in both DNA and RNA
Memory Trick: It’s Got 2 Be GAP
Cytosine, Thymine, and
Uracil
Have only one ring
Cytosine is in both DNA and RNA
Thymine is in DNA only
Uracil
Uracil is in RNA only
Memory Trick: CUT the Pyramid
Structure of DNA:
DNA is composed of two
complimentary strands of nucleotides.
The two strands are joined by
hydrogen bonds which form between
complimentary nitrogen bases:
Adenine with Thymine (A-T or T-A)
They join with 2 hydrogen bonds
Cytosine with Guanine (C-G or G-C)
They join with 3 hydrogen bonds
When DNA is first
made, it is just two
linear strands of
nucleotides joined
together.
Due to internal bonding,
the DNA molecule then
forms into a double
helix (twisted ladder).
a) Directs and controls all cell activities by
making all of the proteins and enzymes
b) Contains all of the genetic information
necessary to make one complete organism
of very exact specifications
RNA is made by DNA.
It is not confined to the nucleus, it moves out
of the nucleus into the cytoplasm of the cell.
It has Ribose sugar instead of Deoxyribose.
It has no thymines, and uses URACIL’s
instead.
It is single stranded and therefore, no helix
is formed.
There are 3 types of RNA.
The function of RNA is to assist DNA in making proteins.
DNA
RNA
Nitrogen bases: A,T,G,C
Nitrogen bases: A, U, G, C
Sugar: deoxyribose
Sugar: ribose
Double stranded
Single stranded
1 type
3 types: a) mRNA – messenger
b) tRNA – transfer
c) rRNA – ribosomal
Found in the nucleus only
Found in the nucleus and the
cytoplasm
Forms a double helix
No helix
DNA makes DNA
DNA makes RNA
Very big molecule
Much smaller molecule
ATP is also thought of as a nucleic acid as it has the
same structure as a nucleotide. The only difference is
that it has THREE phosphate groups instead of one.
This is the energy source for the body.
Our mitochondria turn the energy of glucose into ATP.
Why is it a good molecule to store energy? It takes a lot of
energy to put two phosphate molecules together (both –’ve).
So when you break that bond, a lot of energy is released.
C6H12O6 + 6O2 -----> 6CO2 + 6H20 + energy (heat and ATP)