Transcript Bio03 Organic Molecules

Organic Molecules
The Molecules of Life
Inorganic Vs. Organic
Inorganic molecules do not contain
carbon.
Organic molecules do contain carbon.
Organic molecules are more complex
structures containing carbon atoms
arranged in rings or chains.
Biochemistry
Biochemistry is the chemistry of living
things.
Biochemistry is closely linked to organic
chemistry.
Carbon: The Central Atom
The carbon atom is the central atom of
all organic molecules.
Carbon atoms can join with other
carbon atoms to form long chains.
The ends of these chains can join
together to form ring structures.
Chain And Ring Structures
Figure 3.3
Carbon: The Central Atom
The bonding sites are all located at
equal distances from one another.
Carbon has four electrons in its
outermost energy level.
Theses electrons position themselves in
a propeller like fashion to be as far
away from each other as possible.
Carbon: The Central Atom
Carbon has four places it can bond.
It often forms four separate single
covalent bonds.
Sometimes carbon forms as double
bond as with oxygen.
Models of Molecules
Figure 3.4
Empirical Vs. Structural
Formula
An empirical formula indicates the number
of each kind of atom within the molecule.
The structural formula indicates the
arrangement of the atoms and their bonding
within the molecule.
Molecules that have the same empirical
formula, but different structural formulas are
called isomers.
Variety of Organic Molecules
An enormous variety of organic
molecules is possible because carbon is
able to…
1. Bond at four different places.
2. Form long chains.
3. Combine with many different kinds of
atoms.
Carbon Skeleton
A carbon skeleton is at the core of all
organic molecules.
It is composed of rings or chains.
It determines the overall shape of the
molecule.
Factors That Determine
Differences in Organic
Molecules
The length and arrangement of the
carbon skeleton.
The kinds and locations of the atoms
attached to it.
The ways in which these attached
atoms are combined.
Functional Groups
Functional groups are specific
combinations of atoms attached to the
carbon skeleton.
These functional groups determine the
chemical properties of the molecule.
Macromolecules
Macromolecules (macro = large) are
very large organic molecules.
Four important kinds of
macromolecules:
Carbohydrates.
Proteins.
Nucleic acids.
Lipids.
Polymers
Polymers are combinations of many smaller,
similar building blocks called monomers
(mono = single) bonded together.
Carbohydrates, proteins, and nucleic acids
are all polymers.
The monomers in a polymer are usually
combined by a dehydration synthesis
reaction.
Dehydration Synthesis
Dehydration synthesis (de =
remove; Hydro = water; Synthesis =
combine) involves combining two
molecules through the remove of one
molecule of water.
Dehydration Synthesis
This reaction occurs when two functional
groups (smaller molecules) come close
enough to have an –OH removed from one
and an –H removed from the other.
These are combined to form a molecule of
water and the remaining two segments are
combined to form a macromolecule.
Dehydration Synthesis:
Carbohydrate
Dehydration Synthesis:
Protein
Dehydration Synthesis:
Protein
Hydrolysis
The reverse of a dehydration synthesis
reaction is known as hydrolysis (hydro
= water; lyse = to split or break).
Hydrolysis is the process of splitting s
larger organic molecule into two or
more parts by adding water.
Hydrolysis Of Sucrose
Levels Of Chemical
Organization
Atoms  molecules  monomers
(small building blocks)  polymers
(macromolecules)  carbohydrate,
protein, or nucleic acid.
Carbohydrates
Carbohydrates are composed of carbon,
hydrogen, and oxygen atoms linked
together to form monomers called
simple sugars or monosaccharides
(mono = single; Saccharine = sweet,
sugar).
Carbohydrate Use In Living
Cells
Immediate source of energy.
Provide shape to certain cells (I.E.
Cellulose in plant walls).
Components of coenzymes and
antibiotics.
Components of nucleic acids DNA and
RNA.
Simple Sugars
Simple sugars have equal numbers of
carbon and oxygen molecules and twice
as many hydrogen molecules.
C3H6O3 or C5H10O5.
Simple sugars such as glucose,
galactose, and fructose provide
chemical energy in the human body.
The ending –ose indicates a sugar.
Glucose
Glucose is called blood sugar in the
human bloodstream.
It is found in the sap of plants.
It is the most abundant carbohydrate.
It is a basic building block for other
carbohydrates.
Glucose
Fructose
Fructose is fruit sugar.
Glucose and fructose have the same
empirical formula, but different
structural formulas.
They are isomers.
Fructose Isomers
Complex Carbohydrates
Complex carbohydrates are formed
when simple sugars are combined.
Disaccharide – two simple sugars
bonded together.
Trisaccharide – three simple sugars
bonded together.
Polysaccharide – more than three
simple sugars bonded together.
Disaccharides
Sucrose is the most common
disaccharide. Table sugar is sucrose.
Lactose (milk sugar) and maltose (malt
sugar) are also disaccharides.
All of the above disaccharides have
different levels of relative sweetness,
but all break down into glucose.
Common Complex
Carbohydrates
Cellulose (wood fibers).
Plant starches (amylose).
Glycogen (found in muscle cells).
Humans do not have the enzyme
necessary to digest cellulose.
Cellulose
Glycogen
Proteins
Amino acid monomers join to form the
polymer know as protein.
An amino acid consists of a short
carbon skeleton with an amino
functional group (nitrogen and two
hydrogens) and a carboxylic acid group.
There are about 20 different amino
acids.
Proteins
Dehydration synthesis combines two
amino acids to form a protein.
The nitrogen of an amino group of one
amino acid is bonded to the carbon of
the acid group of another amino acid.
This bonding forms a peptide bond.
Four Levels Of Protein
Structure
Primary – a listing of the amino acids in
their proper order within the
polypeptide.
Secondary – a twisting of specific
sequences of amino acids, the shape of
which is maintained by hydrogen
bonds.
Four Levels Of Protein
Structure
Tertiary – when multiple twists or coils
interact, they can form a globular
structure.
Quaternary – when the globular
structures from different polypeptides
interact, they form a larger globular
structure.
Denatured Proteins
Energy in the form of heat or light can
break down higher levels of protein
structure by breaking hydrogen bonds
within the molecule. The protein is
then said to be denatured.
Brown bottles and refrigeration protect
some medications such as insulin from
becoming denatured.
Types of Proteins
Structural proteins – maintain the shape
of cells and organisms.
They make up the shape of cell
membranes, muscle cells, tendons, etc.
Types of Proteins
Regulator proteins – determine what
activities will occur in the organism.
Enzymes and hormones are regulator
proteins.
Carrier proteins – pick up and deliver
molecules. Transport molecules from
one place in the body to another.
Lipoproteins are an example of carrier
proteins.
Nucleic Acids
Nucleic acids are complex organic
polymers that store and transfer genetic
information within the cell.
Two types:
Deoxyribonucleic acid (DNA).
Ribonucleic acid (RNA).
Nucleic acids are constructed of
monomers known as nucleotides.
Nucleotides
Nucleotides provide a source of energy
for cellular reactions.
Three parts of a nucleotide:
1. A 5-carbon simple sugar molecule
(either deoxyribose or ribose).
2. A phosphate group.
3. A nitrogenous base.
Nucleotides
DNA has deoxyribose sugar and the
bases A, T, G, & C.
RNA has ribose sugar and the bases A,
U, G, & C.
Deoxyribonucleic Acid (DNA)
DNA is composed of two strands, which
form a twisted ladderlike structure
thousands of nucleotides long.
Hydrogen bonds attach base pairs from
one strand to the other.
Base Pairing
Base pairing adheres to strict rules.
Adenine on one strand always pairs
with thymine on another strand in DNA
(or with uracil in RNA).
Guanine always pairs with cytosine (in
both DNA and RNA).
A T (or A U) and G C.
Gene
A gene is a meaningful genetic
message.
It is written using the nitrogenous
bases as letters.
An example of a base sequence follows:
CATTAGACT.
Coding Strand
The strand of DNA or RNA that contains the
message is referred to as the coding strand.
The term genetic code comes from this.
Opposite of the coding strand is the noncoding strand. This strand protects the
coding strand from chemical and physical
damage.
Both strands are twisted in a helix.
3 sets of bases are utilized to make a amino
acid.
Chromosomes
The human body contains 46 strands of
helical DNA called chromosomes.
These strands are like different books
containing many chapters (genes).
Gene
A gene is a segment of DNA that is able to
perform the following functions:
1. Replicate by directing the manufacture of
copies of itself.
2. Mutate, or chemically change, and transmit
these changes to future generations.
3. Store information to determine the
characteristics of cells and organisms.
4. Use the information to direct the synthesis of
proteins.
Ribonucleic Acid (RNA)
Ribonucleic acid (RNA) helps with the
synthesis of proteins.
3 forms:
Messenger RNA (mRNA) – carries the genetic
message of DNA to the ribosome.
Ribosomal RNA (rRNA) – an RNA copy of DNA in
the form of a ribosome.
Transfer RNA (tRNA) – transfers specific amino
acids to the ribosome to form the protein
molecule.
Lipids
3 types of lipids
True fats
Phospholipids (component of cell
membranes)
Steroids (some hormones)