Transcript BIOLOGY * CHAPTER 2

Microbiology – Chapter 2
BIOLOGICAL
CHEMISTRY
Do Now
 What is an atom?
 What is an element?
 What is the name of the table that keeps track of all
the elements?
Why do biologists study chemistry??
 Chemical changes in _________ are essential to all
life processes
 All _______ ________ are made of the same
kinds of matter that make up non-living things
 If you learn how ________ in matter occur you will
understand the _____ ___________ of organisms
Elements
 Elements – ______ _________ that cannot be
broken down chemically into simpler kinds of matter
 Of more than 100 elements fewer than 30 are
important to _______ _______
 More than ____% of the mass of living things is
composed of combinations of just:

_____, ______, _____ and ______
Elements
 ________ _________ – usually part of the
element’s name or the Latin word for the element
 Organized into the _______ _______ of elements
 There are 118 elements, 94 are naturally occurring, the rest are
synthetic (made in particle accelerators)
 Elements listed by increasing atomic number
 Columns – groups of elements with similar properties because
of the number of electrons in their outer shell
 Rows - periods
Atoms – basic units of matter
-________ are the simplest particles of an
element that retain all the ________ of that
element
-Atoms are so small that their true structure has
not been observed
-Models of the atom help us understand their
structure enough to _______ how they will act
in nature
Atoms
Structure – net electrical charge of _______
a. Protons (charge +) 1 AWU
b. neutron (charge 0) 1 AWU
c. electrons (charge -) .008 AWU
AWU – atomic weight unit
_________ – central mass of an atom,
contains protons and neutrons
Atoms
 _________ – high energy particles that
move about the nucleus at high speeds in
one of several different energy levels
- Electrons in _______ energy levels have
more energy than those in ______ energy
levels
- Each energy level can only hold a certain
_________ of electrons
- 1st energy level can hold ___ electrons
-2nd energy level can hold ___ electrons
- In most elements, the outer energy level is
Atom
Number of Protons?
Atom
 animation of an atom
Atomic number – the
number of protons in
the nucleus of the atom
Atomic mass – the
number of protons plus
neutrons in the nucleus
of the atom
Isotopes
_________ – A different form of an element
which has the same number of protons and
electrons, but has a different number of
_________
Carbon (C):
-atomic number is 6 - it has 6 protons
-mass number is 12 – it has 6 protons
and 6 neutrons
-C14 – isotope that has 8 neutrons
Hydrogen Isotopes
Isotopes
Radioisotopes – _________ element
forms whose nuclei can undergo
spontaneous change in which charged
particles and radiant energy are
released
Atoms Activity
 Complete worksheet on atoms
 Finish for homework if not completed in class
Do Now
 What is the positively charged particle in an atom
called?
 What is the negatively charged particle in an atom
called?
 What is the neutral particle in an atom called?
 What is an isotope?
Compound
1. A pure substance made up of ____ __
_____ elements combined chemically
2. The properties of compound _______ from
the elements it is composed of – H2O vs. H
and O
3. The _________ of each kind of element are
fixed – Water always H2O
4. Elements combine and form compounds to
become more ________
5. Elements are more stable when their outer
electron shells are ________
Bonds
Chemical bonds – forces that ____ two or more atoms
a. Covalent bonds – ________ of electrons
(water H2O)
b. Ionic bonds – __________ of electrons
(sodium chloride NaCl)
Chemical Bond Animation
Molecules
 A _________ is the simplest part of a substance
that retains all of the _________ of that substance
and that can exist in a ______ state
 Hydrogen
gas (H2)
 Water (H2O)
Matter Activity
 Complete “Composition of Matter” worksheet.
 Finish what you don’t complete for homework.
Do Now
 What is a compound?
 What is a covalent bond?
 What is an ionic bond?
2. INORGANIC CHEMISTRY
 STUDY OF COMPOUNDS THAT DO NOT
CONTAIN THE THREE ELEMENTS ____, _____,
& ____ AT THE SAME TIME.
 CAN CONTAIN _____ OF THOSE THREE AND
ANY OF OTHER ELEMENTS
ORGANIC CHEMISTRY
 LIVING THINGS ________ GREATLY FROM
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

NON-LIVING THINGS
THERE MUST BE A BIG DIFFERENCE IN HOW
THEY ARE CONSTRUCTED
THEY ARE ACTUALLY CONSTRUCTED OF THE
________ MATERIALS
THE ONLY DIFFERENCE IS IN HOW THEY ARE
___________
ALL BIOLOGY HAS A __________ BASIS
3. ORGANIC CHEMISTRY
 STUDY OF _______ COMPOUNDS - CHEMICAL
BASIS FOR LIVING CELLS
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ALWAYS _____, _____, & ______
SOMETIMES NITROGEN & PHOSPHORUS
USUALLY SMALL AMOUNTS OF METALS
 THERE ARE “FOUR” DIFFERENT CLASSES OF
ORGANIC COMPOUNDS
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______________
______________
______________
______________
Carbohydrates
 Organic compounds of C, H and O
 Used as ________ _________ in cells
 Also found in several __________ structures such
as bacterial capsules
 They are synthesized from water and carbon dioxide
during _____________
Carbohydrates
 _____________ are the simplest carbohydrates
 They are the building blocks for the larger
carbohydrates (_______________)
 Glucose, galactose and fructose are examples of
isomers – they have the same chemical formula
C6H12O6
 But their structures and properties are different
A. CARBOHYDRATES
Glucose
 Represents the basic supply of ______________
in the world
 Half of the world’s __________ exists as glucose
GLUCOSE – UNIVERSAL ENERGY
Disaccharides
 ____________ sugars – composed of _______
monosaccharides held together by covalent bonds
 They are made from glucose molecules through
___________ __________– water is removed
as the new bonds are formed
 Examples are:
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maltose – found in barley and used to ferment beer
lactose – found in milk and digested by bacteria to form
yogurt, sour cream
Sucrose – table sugar and is the starting point in wine
fermentation and may be a cause of tooth decay
DISACCHARIDE – TWO MONOSACCHARIDES
Polysaccharides
 ____________ sugars
 Large compounds formed by joining together 100’s
or 1000’s of _________ molecules
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___________ – used by bacteria as an energy source
___________ – a component of the cell walls of plants and
molds and also used as an energy source by microorganisms
Polysaccharide
Polysaccharide animation
Polysaccharides Activity
 Complete polysaccharides color worksheet
 Finish for homework if not completed in class
Do Now
 What are the 4 classes of organic compounds?
 What 3 elements are carbohydrates made up of?
 What carbohydrate is considered a universal source
of energy?
B. LIPIDS
 __________ in organic solvents, but not in water
 Like carbohydrates, they are composed of C, H, and O,
but with much less _________
 The best known lipids are ________
 Fats are important ___________ energy sources for
living things
 Fats are also components of ______ ____________
LIPIDS
 cell membrane animation
LIPIDS
 Fats consist of a 3 carbon ________ molecule
and up to 3 long-chain ________ ________
 2 major types of fatty acids:
 ___________
– contain the maximum number
of H atoms
 ___________ – contain less than the
maximum number of H atoms
 Unsaturated fatty acids are good for us – they
lower the levels of __________ in the blood
LIPIDS
 Other types of lipids:
____________ – long chains of fatty acids
 Bee’s wax
 Plant leaves
 ____________ – contain a phosphate group
 Cell membranes
 ____________ – composed of several rings of carbon
atoms with side chains
 Cholesterol
 Estrogen
 Testosterone
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C. PROTEINS
 Most __________ organic compounds of living things
 They can be:

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__________
__________ – regulate the rate of chemical reactions
 They are composed of chains of _______ _______
 Each amino acid contains
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Carbon atom
Amino group (NH2)
Carboxyl group (COOH)
Another side group
Amino Acids – there are 20
Proteins
 Amino acids are joined together by __________ bonds
 The __________ of amino acids is extremely important
 One mistake changes the protein (____________)
 Protein Structure:
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Primary – AA sequence
Secondary – AA chain twists into a corkscrew pattern
Tertiary – Protein folds back upon itself
Proteins
Protein structure animation
D. NUCLEIC ACIDS
 Some of the _______ molecules found in organisms
 ________ – genetic material of the chromosomes that carries
the genetic code
 ________ – cell messenger that functions in protein
construction
 Composed of __________
 Carbohydrate molecule (ribose or deoxyribose)
 Phosphate group
 Nitrogenous base
DNA – adenine, guanine, cytosine, thymine
 RNA – adenine, guanine, cytosine, uracil

Nucleic Acids
 DNA is located in the ______________ of the cell
 It passes on the genetic information and directs
_________ synthesis
 DNA molecule consists of 2 single strands of DNA in
opposite directions arranged in a _________ _______
 Nucleic acids can not be altered without disrupting or
killing the organism – this can help us control
______________
DNA Structure
Animation
Acids and Bases
Degree of ________ or _________ is very
important to living systems
You may hear the term pH a lot
What does this mean?
Acids and Bases
 Water can dissociate into:

____________ Ions OH-

____________ Ions H3O+
Acids and Bases
- pH is a measure of a solution’s ___________ ion
concentration
-pH is a scale of _____ - _____
- an acid = more hydronium ions (H3O+)
- a base = more hydroxide ions (OH-)
Acids and Bases
 Acids :
 Have more hydronium ions
 Have a ________ taste
 In concentrated forms can be very ___________

Example:
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Strong acid – HCl (hydrochloric acid)
Weak acid – CH3COOH (vinegar)
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Acid Rain
Acids and Bases
 Bases :
 Have more _________ ions
 Have a ________ taste
 Tend to feel _________ because they react with the oil on
our skin to form soap

Example:

Strong base – NaOH (sodium hydroxide)
Weak base – NH4 (ammonia)

Acids and Bases
 pH scale ranges from 0 – 14:
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Solution with a pH of 0 is very __________
Solution with a pH of 14 is very __________
Solution with a pH of 7 is __________
pH can be measured with pH paper or strips
Acid Rain
 ______ ______is a rain or any other form of
precipitation that is unusually _______ (low pH)
 It can have _________ effects on plants, aquatic
animals, and infrastructure
 Acid rain is caused by _________ of compounds of
ammonium, carbon, nitrogen, and sulfur which react
with the _______ _________in the atmosphere
to produce acids
 Formation results from both ________ sources
(volcanoes, decaying vegetation) and
____________ sources (fossil fuel combustion)
Activity
 Complete Acids/Bases worksheet
 Finish for homework if not completed in class