Stahl Biology
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Unit 2- The Chemistry
of Life Notes
Learning Targets:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Identify elements common to living things.
Describe how ions work.
Compare ionic and covalent bonds
Recognize the importance of hydrogen bonding.
Explain why many compounds dissolve in water.
Compare acids and bases.
Describe the bonding properties of carbon atoms
Compare and understand the importance of the four macromolecules: carbohydrates,
lipids, proteins, and nucleic acids.
Describe how bonds break and reform during chemical reactions
Explain why and how chemical reactions release or absorb energy.
Explain the effect of catalysts on activation energy.
Describe and explain how enzymes regulate chemical reactions.
Unit Opener: Carnivorous plant= Venus flytrap
Like other carnivores, the Venus flytrap eats animals to get
nutrients that it needs to make molecules such as proteins and nucleic
acids. Other chemical compounds made by plant’s cells enable the
Venus flytrap to digest the animals that it eats. These chemicals are
similar to the chemicals that allow you to digest the food that you eat.
Fun Fact!
The Venus flytrap can capture prey even though it has no muscles or
nervous system. When one of six tiny trigger hairs is touched, the
plant responds by moving water in its cells to change the curvature of
the leaves. The convex leaf halves become concave and snap shut in
less than .5 seconds.
If plants can make their own food through photosynthesis, why
would a plant species evolve a mechanism to capture and eat
animals?___________________________________________
Venus flytraps grow in swampy areas that have nitrogen poor soil.
These plants get the nitrogen they need for survival by trapping and
digesting animals.
Stahl Biology
Word
Atom
Element
Isotope
Compound
Ionic Bond
Ion
Covalent Bond
Molecule
Hydrogen Bond
2
Definition
Example
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Word
Cohesion
Adhesion
Mixture
Solution
Solute
Solvent
Buffer
Acid
Bases
Monomer
3
Definition
Example
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Word
Polymer
Carbohydrate
Monosaccharides
Polysaccharides
Lipids
Fatty Acids
Proteins
Amino Acids
4
Definition
Example
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Word
Nucleic Acids
Chemical
Reactions
Reactants
Products
Bond Energy
Equilibrium
Exothermic
reaction
Endothermic
reaction
Activation
Energy
5
Definition
Example
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Word
Catalyst
6
Definition
Example
Enzymes
Substrate
Review- What are the eight characteristics of
living things.
1.______________________________
2.______________________________
3.______________________________
4.______________________________
5.______________________________
6.______________________________
7.______________________________
8.______________________________
What is everything made up of?
 ______________________________________________
Atoms are made up of:

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________
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___________________________________________________
Review of an atom.
Atomic Mass=
Atomic Number=
Elements
 ________________________________________________________
________________________________________________________
 ________________________________________________________
________________________________________________________
 ________________________________________________________
________________________________________________________
Atoms are made up of the same types of particles, so what makes one
element different from another?
_____________________________________________________________
_____________________________________________________________
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How many protons does hydrogen have? Oxygen?
Energy Levels:
1.
______________________________________________________
______________________________________________________
2.
______________________________________________________
3.
______________________________________________________
4.
______________________________________________________
______________________________________________________
5.
______________________________________________________
6.
4 that make up 96 % of your body= carbon, oxygen, nitrogen, and
hydrogen
The other 4% are called trace elements because they are found in
little amounts but we need them to survive-> like calcium, iron,
and potassium.
7.
Why does your blood need iron?
_____________________________________________________________
Why does your body need chromium?
_____________________________________________________________
_____________________________________________________________
Compounds:
1.
2.
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
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Ions:
1. ___________________________________________________________
2.____________________________________________________________
_____________________________________________________________
_____________________________________________________________
3. Either positive or negative
4. Atoms with few electrons= lose electrons and becomes more positive
5.____________________________________________________________
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NaCl
Transfers electron from sodium atom to chlorine atom
________________________________________________________
________________________________________________________
________________________________________________________
________________________________________________________
________________________________________________________
________________________________________________________
Opposites attract (+ / -)
What determines whether an atom becomes a positive ion or a negative
ion?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
Covalent Bonds
 ________________________________________________________
 ________________________________________________________
________________________________________________________
 ________________________________________________________
________________________________________________________
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CO2 Example
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
Molecule:
_____________________________________________________________
_____________________________________________________________
Properties of Water!!!!!
Waters unique properties allow life to exist on Earth.
Polar
Nonpolar
They both tend to remain separate that is why they say, “oil and water
don’t mix.
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Life depends on hydrogen bonds
 ________________________________________________________
________________________________________________________
________________________________________________________
 ________________________________________________________
________________________________________________________
________________________________________________________
Where else can we find hydrogen bonds?
o ___________________________
o ___________________________
Properties of Hydrogen bonds
o Weakest of the bond
Properties of Water
High specific heat=
_____________________________________________________________
_____________________________________________________________
o Very important with cells because our cells release a lot of
heat and water absorbs that heat which allows us to regulate
cell temperatures.
Cohesion->
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
*Makes water molecules stick together.
_____________________________________________________________
_____________________________________________________________
*Ex- beads on a car when it is washed
*Spider walking on top of the water.
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Adhesion->
_____________________________________________________________
_____________________________________________________________
*Water molecules stick to other things.
*Ex- upward curve of the surface of the water-> graduated cylinder
*Ex- plants transport water up their roots to their leaves.
Capillary Action->
_____________________________________________________________
_____________________________________________________________
* Plants transport water from roots to leaves.
* Water moving up a straw.
Many compounds dissolve in water – UNIVERSAL SOLVENT
 Molecules and ions can’t take part in chemical processes inside cells
unless they dissolve in water.
 Materials such as sugar and oxygen cannot be transported from one
part of an organism to another unless they are dissolved in blood,
plant sap, or water based fluids.
Solution=
_____________________________________________________________
_____________________________________________________________
Solvent
Solubility:
Solute
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________________________________________________________
________________________________________________________
________________________________________________________
________________________________________________________
________________________________________________________
Your plasma (liquid part of your blood) is 95% water. Which is the solvent
and solute?
Water= ______________
Dissolved proteins, platelets, minerals, hormones= _____________
Why do the solutes such as proteins and sugars dissolve in the water of
blood plasma?
_____________________________________________________________
_____________________________________________________________
Sum it up! Properties of Water:
1. Hydrogen Bonding- strong cohesion (insects walking on water)
2. Capillary Action- water moves upward (Roots to leaves)
3. Strong Adhesion- attraction between two unlike substances
4. Universal Solvent- dissolves everything
5. High Specific Heat- cools / heats up slowly to allow temperatures in
organisms to maintain homeostasis
6. Expands when freezes making it less dense
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Acids and Bases
Primary notes for this section are in a foldable that we made in class.
Acids
Bases
How is Ph regulated in our bodies?
1.
2.
3.
______________________________________________________
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