Transcript Chapter 4: Carbon Chapter 5: The Large Biological Molecules

The Characteristics of Carbon
and the Large Biological
Molecules
Let’s Review!
Copyright © Amy Brown – Science Stuff
What name is given to a molecule that
contains carbon atoms bonded to other
carbon atoms?
Organic Molecules
What are the four types of organic
compounds?
Carbohydrates
Proteins
Lipids
Nucleic Acids
What elements compose each of these
types of organic molecules?
Carbohydrates – C, H, O
Proteins – C, H, O, N, sometimes S
Lipids – C, H, O
Nucleic Acids – C, H, O, N, P
What are the characteristics of carbon that make
possible the building of such a wide variety of
organic molecules?
1.
2.
3.
4.
5.
6.
7.
8.
9.
Carbon has four valence electrons. It can form four different
bonds with other carbon atoms or other atoms.
Carbon can form chains, branches, rings – a wide variety of
shapes!
Can form unique, 3-D shapes.
Can form strong and stable bonds.
It form single, double or triple bonds.
Carbon compounds to not readily dissociate in water.
There is no limit to the size of the molecule.
Can bond with a wide variety or other elements and functional
groups.
Only carbon has all of these characteristics.
What name is given to an organic molecule
consisting only of carbon and hydrogen?
Hydrocarbon
What name is given to a small, specific group
of atoms that can be attached to a carbon
skeleton?
Functional Group
What are the two functions of functional
groups?
Functional groups give the molecule
its unique shape.
Functional groups behave a certain
way in chemical reactions.
What is the name of this functional group?
Where would you find this functional group?
-OH
Hydroxyl
Found in sugar molecules.
Makes molecules very polar.
What is the name of this functional group?
Where would you find this functional group?
-C=O
Carbonyl
Found in sugar molecules.
Makes molecules very polar.
What is the name of this functional group?
Where would you find this functional group?
-COOH
Carboxyl
Found in proteins and lipids.
Makes molecules very polar.
Has acidic properties
What is the name of this functional group?
Where would you find this functional group?
-NH2 or –NH3+
Amino
Found in all amino acids
What is the name of this functional group?
Where would you find this functional group?
-SH
Sulfhydryl
Found in the amino acid cysteine.
Forms disulfide bridges in the
tertiary structure of a protein.
What is the name of this functional group?
Where would you find this functional group?
-PO4
Phosphate
Found in phospholipids, DNA, RNA,
and ATP
What are the building blocks of
carbohydrates?
The simple sugars such as glucose.
How are simple sugar molecules
recognized? What functional groups will
they have?
They always consist of C, H, and O in
a 1:2:1 ratio.
They have both hydroxyl groups and
carbonyl groups.
What are the building blocks of lipids?
Fatty acids and glycerol
How do you recognize glycerol?
It is a 3 carbon compound with
hydroxyl on each carbon.
There is no 1:2:1 ratio.
How do you recognize a fatty acid?
It has a very long carbon skeleton
with a carboxyl group at one end.
What are the building blocks of proteins?
Amino Acids
How do you recognize an amino acid?
It consists of a carbon atom
bonded to:
1. A carboxyl group
2. An amino group
3. One single hydrogen
4. An “R” group which varies in
each amino acid.
How many amino acids are there?
20
Describe a nitrogenous base.
It is a ringed structure with carbon
and nitrogen alternating in the ring.
It may have a single ring or a double
ring.
Name the nitrogen bases.
Adenine
Thymine
Cytosine
Guanine
What are purines and pyrimidines
A purine is a nitrogen base with 2
rings – adenine and guanine.
A pyrimidine is a nitrogen base with
1 ring – cytosine and thymine.
What name is given to “giant” molecules
that are formed by the joining of many
smaller molecules?
Macromolecules
A long molecule consisting of many similar
or identical building blocks linked together
by covalent bonds.
Polymer
What are “monomers”?
Smaller molecules that are the
repeating subunits that are joined
together to make polymers.
What are the monomers of carbohydrates?
Molecules of simple sugars such as
glucose.
What are the monomers of proteins?
Amino Acids
What is a dehydration reaction?
This is the reaction that joins two
monomers together. A water molecule
is removed between two monomers.
One monomer contributes the “OH”
and the other contributes the “H”
What is a hydrolysis reaction?
Polymers are disassembled to
monomers by hydrolysis. The bonds
are broken by the addition of a water
molecule.
What are three examples of carbohydrates?
Sugars, starches, and celluloses.
How are the carbohydrates classified?
By the number of sugar monomers
composing them.
What are the three levels of sugar
composition? Describe each.
Monosaccharides – One molecule of sugar.
Disaccharides – Two molecules of sugar bonded
together.
Polysaccharides – Many molecules of sugar bonded
together.
What purpose do the simple sugars serve?
Give 2!
Glucose is the principle energy source of all living
organisms. It is converted to ATP by the
mitochondria.
The carbon skeletons can serve as the raw materials
for the synthesis of other types of biological
molecules.
What is a glycosidic linkage?
It is a covalent bond formed between 2
monosaccharides by a dehydration reaction.
Give a purpose of disaccharides.
Sugars are transported throughout a plant in
the form of disaccharides.
(Sugars are transported as monosaccharides
in animals.)
What are two types of polysaccharides?
Structural Polysaccharides
Storage Polysaccharides.
What are the two types of storage
polysaccharide? Define each.
Starch – This is how plants store their excess
glucose molecules. Many, many glucose molecules
are bonded together to form starch.
Glycogen – This is how animals store excess
glucose. Many molecules of glucose are bonded
together by the liver to form glycogen.
What are the two types of structural
polysaccharide? Define each.
Cellulose – Forms the tough, fibrous
material found in the cell wall of plants.
Chitin – Used by arthropods to build their
exoskeletons. Used by fungi as the
structural component of their cell wall.
Name the types of lipids.
Fat
Oil
Wax
Phospholipids
Cholesterol
What is a distinguishing characteristic of
lipids?
They are nonpolar and are not soluble
in polar solvents such as water.
What type of molecule is this. Explain how
you know.
It is a simple sugar. There is only C, H,
and O and it is present in a 1:2:1 ratio.
What type of molecules are these? Explain
how you know.
These are amino acids. They have a carbon atom
bonded to a carboxyl group, an amino group, a
single hydrogen and an “R” group.
What type of molecule is this. Explain how
you know.
It is a lipid. It has one molecule of glycerol
and three fatty acid tails.
What type of molecule is this. Explain how
you know.
What is this?
What is this?
Glycerol
Fatty Acid
What type of molecule is this. Explain how
you know.
It is a simple sugar. It has the formula
CH2O.
What is a saturated fatty acid?
They contain NO carbon to carbon double
bonds. As many hydrogen atoms as possible
are bonded to the carbon atoms.
What is an unsaturated fatty acid?
They DO contain carbon to carbon double
bonds. There will be a “kink” in the tail
wherever a double formed is found.
Why are the unsaturated fatty acids more
healthy for us than the saturated fatty
acids?
The “kinky tails” of the unsaturated fats prevent
them from packing too close together. They forms
liquids at room temperature.
The saturated fatty acids have no kinks and will
pack very closely together, forming solids. These
may lead to cardiovascular diseases.
What are some uses of Lipids?
1.
2.
3.
4.
Good source of energy.
They are used to insulate the body.
They cushion the internal organs.
Phospholipids are a structural
component of membranes.
How are the phospholipids different from
other fats?
They are composed of glycerol, but only
have 2 fatty acid tails instead of three. One
tail is saturated, the other is unsaturated.
Describe how the lipids are arranged in a
membrane.
There is a double layer (bilayer) of lipids in the
membrane. The hydrophilic glycerol head is found
on the outer edge and the inner edge of the
membrane. The hydrophobic fatty acid tails point
to each other across the middle of the membrane.
What is the importance of this
arrangement?
The glycerol molecules draw water to the
membrane, but the hydrophobic fatty acid
tails make the membrane insoluble in water.
What is the purpose of wax in biological
systems.
Wax is generally used as a water proofing
material on leaves, fruits, feathers, fur.
List some of the purposes of proteins.
1.
2.
3.
4.
5.
6.
7.
Enzymes
Hormones
Transport (hemoglobin)
Contractile (muscle tissue)
Antibodies
Membrane structure
Structural proteins
What is a peptide bond?
A covalent bond formed by a dehydration
reaction that links the carboxyl group of
one amino acid to the amino group of
another amino acid.
What is a polypeptide?
A chain of amino acids held together by
peptide bonds. It is not yet a fully
functioning protein.
As proteins go, remember this!
__________ determines __________!!
Shape determines function!
What are the four levels of protein
organization?
Primary
Secondary
Tertiary
Quaternary
What is the primary structure of a protein?
The primary structure is the unique
sequence of amino acids that are put
together by the ribosomes of the cell.
What is the secondary structure of a
protein?
The secondary structure is the initial folding
and shaping of the polypeptide. It is the
repetitive folding due to the formation of
hydrogen bonds at regular intervals.
What is the tertiary structure of a protein?
Tertiary structure is irregular contortions of
a protein due to bonding between side
chains. Tertiary structure gives the protein
its shape. It is due to hydrophobic
interactions and disulfide bridges.
What are hydrophobic interactions?
It is the clustering of hydrophobic side
chains at the center of the protein.
What are disulfide bridges?
Covalent bonds between the side chains of
two cysteine amino acids. The sulfur of one
cysteine bonds to the sulfur of the second.
What is the quaternary structure of a
protein?
Two or more polypeptide subunits combine
to form a functional protein.
What has happened when a protein has
become denatured?
A denatured protein has lost its unique, 3-D
shape. It is inactive and can no longer carry
out its function.
What are the two types of nucleic acids?
DNA
RNA
What are nucleic acids composed of?
Nucleotides
What are the three components of a
nucleotide?
Sugar, phosphate, nitrogen base.
Created by Amy Brown –
Science Stuff
Copyright © November 2012
Amy Brown (aka Science Stuff)
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