Chapter 2. What’s The Matter? All of the materials around you are made up of matter. You are made...
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The Chemistry of Life Chapter 2
Chapter 2. What’s The Matter? All of the materials around you are made up of matter. You are made up of matter, as are the chair you sit on and the air
Atoms 100 million atoms in row = 1 cm Made of three things Protons Positive charge Found in nucleus Neutrons Neutral charge Found in nucleus Electrons Negative charge Found in cloud around nucleus
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The Chemistry of LifeWhat’s The Matter?
All of the materials around you are made up of matter. You are made
up of matter, as are the chair you sit on and the air you
breathe.
1. Give an example of solid matter.
2. Give an example of liquid matter.
3. Give an example of gaseous matter.
4. Is all matter visible?
5. Does all matter take up space?
Atoms
Made of three things
Elements and Isotopes
Element
A pure substance made up of only one type of atom
Ex: carbon, oxygen, hydrogen
In Your Notebook
Draw a diagram of a hydrogen atom, which has an atomic number of
1.
Look on page 34 if you need help.
Chemical Compounds
Ex: H2O, NaCl, HCl
The physical and chemical properties of a compound are usually very
different from the elements from which it is formed.
Sodium-Na-very soft and can be cut with knife, it is highly
flammable
Chlorine-Cl-poisonous, greenish gas used in WWI
Put the together and you get NaCl which is table salt
We eat it everyday without harm
Chemical Bonds
Two types
Ions = charged atom
Electrons are shared
When you join atoms using covalent bonds you form a molecule. It’s
the smallest unit of most compounds.
In Your Notebook
In your own words, describe the differences between ionic and
covalent bonds.
Van der Waals Forces
Electrons not evenly shared
When molecules are close
slight attraction for nearby
2.2 Water, Water Everywhere
If you have ever seen a photograph of Earth from space, you know
that much of the planet is covered by water. Water makes life on
Earth possible. If life as we know it exists on some other planet,
water must be present to support that life.
1. Working with a partner, make a list of ten things that have
water in them.
Water, Water Everywhere
2. Exchange your list for the list of another pair of students. Did
the two lists contain some of the same things? Did anything on the
other list surprise you?
3. Did either list contain any living things?
Characteristics of Water
There is an uneven distribution of electrons
Characteristics of Water
Attraction between molecules of the same substance
Water likes to stick together – that’s why it forms drops on a
smooth surface
Surface Tension
Attraction between molecules of a different substance
Water likes to stick to the edges of glass and plastic
Characteristics of Water
Takes a long time to heat up
This is why it is in your car radiator
Also takes long time to cool down
Protects your body from drastic temperature changes
In Your Notebook
1. What does it mean when a molecule is said to be polar?
2. Describe how hydrogen bonds between water molecules occur.
Solutions and Suspensions
Mixture
Two or more elements or compounds that are physically mixed
together but not chemically combined
Ex: salt and pepper
Solvent-water
Solutions and Suspensions
Ex: blood
Acidic = more H+
Basic = more OH-
Adding acid to buffered
Soap, Lemon Juice, Milk, Acid Rain
What is the difference between a solution and a suspension?
The acid hydrogen fluoride can be dissolved in pure water. Will the
pH of the solution be greater or less than 7?
2.3 Life’s Backbone
1. Write a brief description of what you think fats, proteins, and
carbohydrates are. If you know of other elements that are found in
these nutrients, write those elements next to the nutrients in
which they are found.
The Chemistry of Carbon
This means it can bond with many elements
Ex: hydrogen, oxygen, phosphorus, sulfur and nitrogen
Carbon can also bond with itself
This allows long chains and rings to be formed
Macromolecules
Formed by polymerization
Used as source of energy and for structure in plants
Monosaccharides
Have glycerol head and fatty acid chains
Saturated
Unsaturated
In Your Notebook
Answer the questions in the analyzing data section on page 48
Macromolecule #3-Nucleic Acids
Store and transmit genetic information
Made of nucleotides
Polymers of amino acids
Control rates of reactions
Help fight disease
In Your Notebook
What properties of carbon explain carbon’s ability to form
different large and complex structures?
Name the four groups of organic compounds (macromolecules) found in
living things.
Explain the relationship between monomers and polymers.
2.4 Matter and Energy
Have you ever sat around a campfire or watched flames flicker in a
fireplace? The burning of wood is a chemical reaction—a process
that changes one set of chemicals into another set of
chemicals.
1. Wood doesn’t burn all by itself. What must you do to start a
fire? What does this mean in terms of energy?
2. Once the fire gets started, it keeps burning. Why don’t you need
to keep restarting the fire?
Chemical Reactions
A process that changes one set of chemicals into another.
Reactant
Product
body is based on chemical reactions
Energy in Reactions
Spontaneous Reactions
Activation Energy
In Your Notebook
What is activation energy?
Describe the difference between a reaction that occurs
spontaneously and one that does not.
Enzymes
Proteins that act as biological catalysts.
Catalyst = a substance that speeds up the rate of chemical
reactions
Enzymes
CO2 + H2O H2CO3
This reaction removes carbon dioxide from bloodstream. But, it’s
very slow.
Our body has catalyst known as carbonic anhydrase that speeds this
reaction up by a factor of 10 million.
Enzyme-Substrate Complex
Brings the reactants (substrates) together
Less energy is needed if they are close by
Regulation of Enzyme Activity
Ex: In humans most enzymes work best at 98.6F
If you get a fever your body processes slow down because the
enzymes don’t work and all of the chemical reactions are slowed.
The enzymes lose their shape and no longer fit with the substrates.
The key no longer fits in the lock.
In Your Notebook
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