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• Subatomic particle Charge
Location
proton
+
nucleus
neutron
none
nucleus
electron
surrounds nucleus
Atomic number (#)= number of protons
(=number of electrons in neutral atom)
Mass number (AM)= number of protons +
number of neutrons
Macroelements- need large quantities
6 elements make up 98% by mass
C, H, N, O, P, S
Microelements (or trace elements)Need very small amounts but critical!!
ex. Selenium (Se) is an
antioxidant that helps
prevent cell damage from
free radicals, also help
thyroid function and
boost immune system
Radioactive Isotopes: nucleus decays
Used in medical research
Compounds are different from the elements that make them up!!
Properties of atoms due to:
electronegativity
valence electrons
configuration
size
Ex. Ions
• Bonds (ionic and covalent)- lose, gain or share
electrons in order to fill valence shell (stability)
– All atoms want 8 e- in their outermost shell
Due to electronegativity!
•Ionic- >1.7
•Polar covalent- 0.4- 1.7
•Covalent- < 0.4
• Hydrogen bondsattraction of H to
partial negative
charge (due to
polar covalent
bonds between
oxygen and
hydrogen)
Hydrogen
with
oxygen,
nitrogen,
etc.
Degrade with heat,
Change in pH, or
Chemical treatments!
Weak
bondStrong
force
And remember: Structure determines
Function!!!!!
Should we control a chemical that:
•Causes excessive sweating and vomiting.
•Is a major component in acid rain.
•Can cause severe burns in its gaseous state.
•Accidental inhalation can kill you.
•Contributes to erosion.
•Decreases the effectiveness of car brakes.
•Has been found in tumors of terminal cancer
patients.
What is the chemical?
Dihydrogen monoxide
H2O
H+ + OH-
Pure water ion conc. Is 10-7 M
Adding solutes disrupts balance
Acid- adds H+
Base- reduces H+ (adds OH-)
•Log based
•Acids pH <7
•Neutral pH=7
•Base pH >7
•[H+] + [OH-] = 14
•Properties of both acid and base
•Resist pH shifts
•Very important in living organisms!
2006- The movement of water through vascular plants
is important to their survival.
a. Explain the mechanism of water movement
through vascular plants during transpiration.
Include a discussion of how the anatomy of
vascular plants and the properties of water
contribute to this process.
2003B- Water is important for all living organisms.
The functions of water are directly related to its physical
properties
a. Describe how the properties of water contribute to
TWO of the following
* transpiration
* thermoregulation in endotherms
* plasma membrane structure
Forms 4
covalent
bonds
Bonds easily
to itself!
Tetrahedral
molecular
shape
Structural
Enantiomers
Geometric
Built of monomers
(subunits)
Water removed
•Makes covalent bonds (stores energy)
•Joins two monomers
Water added
Breaks bonds (releases energy)
2003B- Water is important for all living
organisms.
The functions of water are directly related to its
physical properties.
b. Water serves as a reactant and a product
in the carbon cycle. Discuss the role of
water in the carbon cycle.
•C, H, O in 1:2:1 ratio
•Used for fuel, structure, and receptors
•Simple or complex
•Storage and
structure
•Hydrophobic
•C, H, O components- high in C
•High in energy
•Fats solid, oils liquid
•Made of fatty acids and glycerol
•“Full”- no double bonds
•Straight chained
•Solid
•Found in fats
•One or more C=C bonds (can accept
more H
•Bent chains
•Liquid
•Found in oils
•Energy storage, insulation, cushions organs
•Only 2 fatty acids
•Hydrophilic head, hydrophobic tail
•Membrane bilayers
•Four fused rings with functional groups
•Ex. Cholesterol and hormones
Peptide bond
• C, H, O, N, sometimes S
• Molecular tools
• Structure, enzymes, antibodies
Transport, movement, receptors, hormones
• Chains of amino acids linked by peptide
bonds
•Gives protein its properties
•Made of nucleotides (nitrogen base,
pentose sugar, phosphate)
•Informational
•C, H, O, N, P
•Deoxyribose
•Double stranded
•Thymine
•Makes up genes
•Ribose
•Single stranded
•Uracil
•Structure and protein synthesis
“Spontaneous”
Not “Spontaneous”