Chapter 4: Carbon and the Molecular Diversity of Life (Concept 5.1…
Chapter 4: Carbon and the Molecular Diversity of Life
Concept 4.1 Organic Chemistry is the Study of Carbon Compounds
The study of compounds containing carbon & organic.
Organic compounds were found in only living organisms, containing in a life force beyond physical & chemical laws.
Created urea, an organic compound in animal urine.
organic compounds range from simple to colossal molecules, w thousands of atoms.
Ex: methane (CH4); proteins
Organic Molecules and the Origin of Life on Earth
Over all % of the major elements of life are uniform from one organism to another. reflects common evolutionary of all life.
Concept 4.2 Carbon Atoms can form Diverse Molecules by Bonding to Four Other Atoms
Key to an atom's chemical characteristic.
Determines kinds & numbers of bonds an atom will form w other atoms.
those in the outermost shell, available to form bonds w other atoms.
The Formation of Bonds with Carbon
A carbon atom completes its valence shell by sharing 4 electrons w other atoms so 8 electrons are present.
Each pair of shared electrons constitutes a covalent bond.
In organic molecules, carbon forms single or double covalent bonds.
Each carbon atom acts as an intersection point.
a molecule can branch up to 4 directions.
enables carbon to . make large, complex molecules.
Molecules are 3D
the shape of a molecule is central to its function
number of unpaired electrons in valence shell of atom = atoms valence
number of covalent bonds it can form
Molecular Diversity Arising from Variation in Carbon Skeletons
Carbon chains form the skeletons of most organic molecules.
Skeletons vary in length.
Straight, branched, or arranged in closed rings.
Some have double bonds, vary in number and location.
organic molecules consisting of only carbon & hydrogen.
major components of petroleum
not prevalent in most living organisms, but cells organic molecules have regions only C & H
compounds w same number of atoms of the same elements, but diff structures & properties.
show the variation in the architecture of organic molecules.
differ in covalent arrangements of their atoms.
differ in the location of double bonds.
carbons have covalent bonds to the same atoms, atoms differ in their spatial arrangements due to inflexibility of double bonds.
arrangement w both Xs on same side of double bond
Xs on the opposite side
Isomers that are mirror images of each other that differ in shape due to asymmetric carbon, one that is attached to 4 diff atoms/groups of atoms
Can be arranged left handed or right.
Concept 4.3 A Few Chemical Groups Are Key to Molecular Function
Properties of an organic molecule depend on not only the arrangement of its carbon skeleton but the various chemical groups attached to it.
Chemical Groups Most Important to the Process of Life
Chemical groups directly involved in chemical reactions.
7 chemical groups most important in biological processes:
hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, & methyl groups.
first 6 are chemically reactive & hydrophilic (except sulf.)
Methyl is not reactive, but serves as a recognizable tag on biological molecules.
ATP: An Important Source of Energy for Cellular Processes
ATP (Adenosine Triphosphate)
A more complicated organic phosphate.
consists of organic molecules called adenosine attached to a string of 3 phosphate groups:
The Chemical Elements of Life
Living matter consists of C, O, H, N, W smaller amts of phosphate & sulfur.
Concept 5.1 Macromolecules are Polymers, Built form Monomers
Large carbs, lipids, & NA are chainlike molecules
a long molecule consisting of many similar/identical building blocks linked by covalent bonds.
each class is made up of a diff type of monomer
Repeating units that serve as the building blocks of a polymer & are smaller molecules.
some have functions of their own
The Synthesis & Breakdown of Polymers
chemical mechanisms where cells make & break down polymers are same in all cases
in cells, this process is faciliated by enzymes.
specialized macromolecules that speed up chemical reactions.
EX: reaction connecting monomers
a reaction where 2 molecules are covalently bonded to each other w the loss of a water molecule.
polymers are disassembled by monomers by hydrolysis
a process thats the reverse of the dehydration reaction
bond bt monomers is broken by the addition of a water molecule
Diversity of Polymers
cells have many diff macromolecules
inherited diffs bt close relative reflect small variations in polymers, particularly in DNA & proteins
unrelated individuals are more extensive, and those between species are greater still
Concept 5.2 carbohydrates serve as fuel and Building Material
include sugars and polymers of sugars
simplest: monosacccharides/simple sugars
carb macromaolecules are polymers called polysaccharides composed of many sugar building blocks
generally have molecular formulas that are some multiple of the unit CH2O.
glucose is the most common one
consists of 2 monosaccharides joined by a glycosidic linkage.
Glycosidic Linkage - a covalent bond formed bt 2 monosaccharides by a dehydration reaction
macromolecules, polymers w a few thousand monosaccharides joined by glycosidic linkages.
both plants & animals store sugars for later use int eh form of this.
a polymer of glucose monomers
animals store a polysaccharide called this
a polymer of glucose thats like amylopectin but more branched
organisms build strong materials from this.
a major component of the tough walls that enclose plant cells
a structural polysaccharide, the carbs used by arthropods to build their extoskeletons,
Concept 5.3 Lipid are a diverse group of Hydrophobic Molecules
doesnt include polymers
not big enough to be considered macromolecules
constructed from 2 kinds of smaller molecules, glycerol & fatty acids
has a long carbon skeleton, 16 or 18 carbon atoms in length
the resulting fat, consists of 3 fatty acids linked to one glycerol molecule
Saturated/Un Fatty Acid
Steroids - lipids
The Molecules of Life
- on the molecular scale, carbohydrates, lipids, & nucleic acids are huge & called that.
Most important large molecules in all living things.
it can be sorted into 4 main classes
large biological molecules
the architecture is an essential role to its function.
exhibit unique emergent properties.
Concept 5.4 Protiens include a diversity of structures
chemical agents speed up reactions
Roles of Nucleic Acid
deoxyribonucleic acid (DNA)
Genomics and proteomics have transformed biological inquiry and apps