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Chapter 2: The Chemistry of Microbiology

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Matter
- all materials that occupy space and have mass.
What is matter composed of?
-atoms
Atom
- simplest form of matter not divisible into simpler substances
Protons:
(+) subatomic particles
Neutrons:
neutral subatomic particles
Electrons:
(-) subatomic particles
Element
- pure substances with a characteristic number of protons, neutrons, and electrons and predictable chemical behaviors.
Atomic number
- number of protons.
Mass number
- number of protons and neutrons.
Isotopes
- variant forms of the same element that differ in the number of neutrons.
Atomic weight
- average mass numbers of all isotopic forms.
Electron orbitals
- volumes of space surrounding the atomic nucleus where electrons are likely to be found.
Molecule
- a chemical substance that results from the combination of two or more atoms.
Compounds
- molecules that are combinations of two or more different elements.
Formula/Mass weight
- sum of all of the atomic masses of the atoms a molecule contains.
Chemical bonds
- when 2 or more atoms share, donate, or accept electrons to form molecules and compounds.
3 Types of Chemical Bonds
covalent, ionic, and hydrogen
Covalent bonds
- electrons are shared among atoms.
Polar covalent bonds
- unequal sharing.
Nonpolar covalent bonds
- equal sharing.
Ionic bonds
- electrons are transferred to one atom forming positively charged cations and negatively charged anions.
Hydrogen bonds
- weak bonds between hydrogen and other atoms.
Energy exchange in cells is a result of the
movement of.....
-electrons from one molecule to
another.
Oxidation
- the loss of electrons.
Reduction
- the gaining of electrons.
Redox reactions
- essential to biochemical processes.
Reactants
- molecules starting a reaction.
Products
- substances left by a reaction.
Synthesis reaction
- the reactants bond together in a manner that produces an entirely new molecule.
Solution
- a mixture of one or more substances called solutes, dispersed in a dissolving medium called a solvent.
Most biological activities occur in...
-aqueous (water-based) solutions
Hydrophilic molecules
- dissolve in water.
Hydrophobic molecules
- repel water.
Amphipathic molecules
- have both hydrophilic and hydrophobic properties.
Ionization of H2O
-releases hydrogen ions [H+] and hydroxyl ions [OH-].
pH scale
- ranges from 0 to 14, expresses the concentration of H+ ions.
Organic chemicals
- compounds containing carbon bonded to hydrogens.
Carbon is the fundamental element of____.
-life.
Biochemicals
-organic compounds produced by living things.
Macromolecules
-large compounds assembled from smaller subunits.
Monomer
-a repeating subunit.
Polymer
-a chain of monomers.
4 Major Classes of Biologically Important Macromolecules
-Carbohydrates - monosaccharides, disaccharides, polysaccharides
-Lipids - triglycerides (fats and oils), phospholipids, steroids
-Proteins
-Nucleic acids - DNA, RNA
Carbohydrates
-Sugars and polysaccharides
-Saccharide
Sugars and polysaccharides
-General formula (CH2O)n
-Aldehydes and ketones
Saccharide
-simple carbohydrate
Monosaccharide
3-7 carbons.
Disaccharide
two monosaccharides.
Polysaccharide
- five or more monosaccharides.
Dehydration synthesis
-loss of water in a polymerization reaction.
Carbohydrates Functions
- cell structure, adhesion, and metabolism
Lipids
-Long or complex, hydrophobic, C - H chains
-Triglycerides, phospholipids in membranes, steroids like cholesterol.
Lipids Functions
-Triglycerides - energy storage
-Phospholipid - major cell membrane component
-Steroids - cell membrane component
Proteins
-Predominant molecules in cells
-Monomer - amino acids - 20
-Polymer - peptide, polypeptide, protein
Subunits linked by peptide bonds
-Fold into very specific 3-D shapes
Proteins Functions
- support, enzymes, transport, defense, movement.
Nucleic Acids
-DNA and RNA- Carry the genetic information in all cells which is decoded into the sequence of amino acids in protein molecules.
-Monomer - nucleotide (DNA and RNA's subunit).
DNA - deoxyribonucleic acid
-A,T,C,G - nitrogen bases
-Double helix
-Function - hereditary material
RNA - ribonucleic acid
-A,U,C,G - nitrogen bases
-Function - organize protein synthesis
how is DNA is formed?
-by two very long polynucleotide strands linked along their length by hydrogen bonds
ATP
-The Energy Molecule of Cells.
Adenosine triphosphate -Nucleotide - adenine, ribose, three phosphates
ATP Function
- transfer and storage of energy.
Viruses
- Nucleic acid surrounded by a protein coat. Inactive outside of a host.
Viroids
- Simpler and smaller than viruses, consiting of only a single, short piece of nucleic acid (RNA), without a protective coat.
Prions
- Consist only of protein (No DNA or RNA). Responsible for at least seven neurodegenerative diseases which are always fatal.
Chromosome
- An array of genes responsible for the determination and transmission of hereditary characteristics.
Ribosome
- Structure that facilitates the joining of amino acids during the process of translation; composed of protein and rRNA.
Mitochondria
- Where the majority of ATP synthesis occurs.
Nucleus
- A membrane-bound organelle in a euk. cell that contains chromosomes and the nucleolus.
Nucleolus
- Where rRNAs are synthesized.
The smallest unit of matter with unique characteristics is
-electron -molecule -atom -proton
-atom
The____charge of a proton is exactly balanced by the ____charge of a (an)____.
-positive
-negative
-electron
Electrons move around the nucleus of an atom in a pathway called____.
-obitals.
Which part of an element does not vary in number?
-proton
If a substance contains two or more elements of differnt types, it is considered____.
-a compound.
Bonds in which atoms share electrons are defined as____bonds.
-covalent
A hydrogen bond can form between____adjacent to each other.
-a hydrogen atom and an oxygen atom
An atom that can donate electrons during a reaction is called____.
-a reducing agent.
In a solution of NaCl and water, NaCl is the ____and the water is the ____.
-solute
-solvent
A solution with a pH of 2____than a solution with a pHof 8.
-has more H+
Fructose is a type of____.
-monosaccharide.
Bond formation in polysaccharides and polypeptides is accompanied by the removal of a____.
-water molecule
The monomer unit of polysaccharides such as starch and cellulose is____.
-glucose.
A phospholipid contains____.
-two fatty acids and a phosphate bound to glycerol.
Proteins are synthesized by linking amino acids with____bonds.
-peptide
The amino acid that accounts for disulfide bonds in the tertiary structure of protein is____.
-cysteine
DNA is a hereditary molecule that is composed of____.
-deoxyribose, phosphate, and nitrogen bases.
What is meant by the term DNA replication?
-interpretation of the genetic code.
Proteins can function as____.
-enzymes
-receptors
-antibodies
RNA plays an important role in what biological process?
-protein synthesis.