CHAPTER 2: ESSENTIAL CHEMISTRY
CHAPTER 3: THE MOLECULES OF LIFE
Chapter 2: Essential Chemistry for Biology
Living and non-living substances are both composed of matter. The basic unit of matter is the atom. Understanding atomic structure allows us to see how atoms interact to form molecules and compounds by ionic or covalent bonding. The chemical properties of water, acids and bases are critical to understanding the chemistry of life.
Chapter Outline
Some Basic Chemistry
I. Matter, Elements and Compounds
Matter is anything that occupies ____________ and has ______________.
The three physical states of matter on earth are:
1. _________________
2. _________________
3. _________________
Matter is composed of ________________________________.
______________________ are substances that cannot be broken down into other substances.
There are _______ naturally occurring elements on earth. ______________ are essential to life. Four of these make up _________ of the weight of the human body.
__________________ elements occur in smaller amounts.
Elements can combine to form _______________________________. These are substances that contain two or more ________________ in a fixed ratio.
II. Atoms
Each __________________ consists of kind of atom.
Atom is the smallest unit of _______________________ that still retains the properties of an _______________________.
Atoms are composed of subatomic particles:
1. _____________________
2. _____________________
3, _____________________
Most atoms have protons and neutrons packed tightly into the ____________________. The ______________ orbit the nucleus.
The number of protons, the ____________________________, determines which element it is. An atom's ______________ number is the sum of the number of protons and neutrons. Mass is the measure of the amount of ______________ in an object.
A. Isotopes
Isotopes are alternate _____________ forms of an element. They have the same number of _____________ and _________________. But they have different number of ______________.
In radioactive isotopes, the _______________ decays giving off particles and energy.
B. Electron Arrangement and the Chemical Properties of Atoms
Electrons determine how an atom behaves when it encounters other ________________. Electrons orbit the nucleus of an atom in specific ______________________. The number of electrons in the outermost shell determines the ______________________________ of an atom.
III. Chemical Bonding and Molecules
______________________________ enable atoms to give up or acquire electrons in order to complete their outer shell. The atoms are held together by _________________.
A. Ionic Bonds
When an atom loses or gains electrons, it becomes _________________________________. Charged atoms are called ___________. ____________ bonds are formed between oppositely charged ions.
B. Covalent Bonds
A covalent bond forms when two atoms ______________ one or more pairs of outer-shell electrons.
Why do atoms react? http://www.tvdsb.on.ca/westmin/science/sbioac/biochem/react.htm
C. Hydrogen Bonds
Water is a compound in which the electrons in its covalent bonds are shared _____________________________. This causes it to become a _______________ molecule, one with __________________ charges on both ends.
The __________________ of water results in weak electrical attractions between neighboring water molecules.
Click on http://www.stolaf.edu/people/giannini/flashanimat/water/water.swf for an animation of hydrogen bonding. This site has an animation of the property of water and its polarity http://programs.northlandcollege.edu/biology/Biology1111/animations/hydrogenbonds.html
IV. Chemical Reactions
Changes in the chemical composition of matter are called ______________________________. Chemical reactions include __________________ and _________________. Chemical reactions can not create or destroy __________________, they can only __________________ it.
For an animation on chemical reactions, click on http://www.wisc-online.com/objects/index.asp?objID=AP13004
Water and Life
The abundance of _______________ is a major reason Earth is habitable. Water makes up ________________________ of our cells.
V. Water's Life-Supporting Properties
The ______________________ of water molecules and the ________________________________ that results explain most of water's life-supporting properties:
1. ______________________________________
2. ______________________________________
3. ______________________________________
4. ______________________________________
A. The Cohesion of Water
Water molecules stick together as a result of ________________________. This is called __________________________. ________________________ is the measure of how difficult it is to stretch or break the surface of a liquid. _________________________ give water an unusually high surface tension.
B. How Water Moderates Temperatures
Because of hydrogen bonding, water has a strong resistance to _________________________________. _______________ is the amount of energy associated with the movement of the atoms and molecules in a body of matter. ______________________________ measures the intensity of heat.
Water can absorb and store large amounts of _____________ while only changing a few degrees in temperature. Water can ________________ temperatures. Earth's giant water supply causes __________________________ to stay within limits that permit life. ___________________________ removes heat from the Earth and from organisms.
C. The Biological Significance of Ice Floating
When water molecules get cold, they move apart forming _____________. The ____________________ of ice is lower than liquid water. Since ice floats, ponds, lakes and even oceans do not _________________________________.
D. Water is the Solvent of Life
A ____________________ is a liquid of two or more substances evenly mixed. The dissolving agent is called the ____________________. The dissolved substance is called the ________________________.
When water is the solvent, the result is an ______________________ solution.
The chemistry of water: http://www.biology.arizona.edu/biochemistry/tutorials/chemistry/page3.html
VI. Acids, Bases, and pH
_______________ is a chemical compound that donates H+ ions to solutions.
_______________is a compound that accepts H+ ions and removes them from the solution.
To describe the acidity of a solution, we use the ______________________.
________________ are substances that resist pH change. They accept H+ ions when in _____________. They donate H+ ions when they are depleted.
Buffers: http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/buffer12.swf and http://www.tvdsb.on.ca/westmin/science/sbioac/biochem/buffer.htm
An overview of water and pH: http://www.johnkyrk.com/H2O.html
VII. Evolution Connection: Earth before Life
Earth began as a cold world about ________________ billion years ago. The planet eventually melted from heat produced by:
1. __________________
2. __________________
3. __________________
The first atmosphere was probably composed of hot ________________ gas. A new atmosphere was formed from the gases belched from _____________.
Chapter 3: The Molecules of Life
The formation and diversity of organic molecules, including carbohydrates, lipids, proteins, and nucleic acids is explained by the chemistry of carbon. Many human examples are used to illustrate the central importance of chemical process in life.
Chapter Outline
Organic Molecules
A cell is mostly ______________. The rest of the cell consists mostly of __________________________. _____________________ is the study of carbon compounds.
I. Carbon Chemistry
Carbon is versatile. It has _____________ electrons in an outer shell that holds eight. Carbon can share its electrons with other atoms to form up to _________ covalent bonds. Carbon can use its bonds to:
1. ________________________________________
2. ________________________________________
The simplest organic compounds are _____________________________. These are organic molecules containing only carbon and hydrogen atoms. The simplest hydrocarbon is _______________________. Larger hydrocarbons are________________________________________________________. The hydrocarbons of _______ molecules provides energy to our bodies.
Each type of organic molecule has a unique _________________________________ shape that defines its ____________________ in an organism.
II. Giant Molecules from Smaller Building Blocks
Biologists call large molecules ______________________________. Examples are:_______________________________________________________
Most macromolecules are _____________________. Polymers are made by stringing together many smaller molecules called ____________________. Cell link monomers by ______________________________.
Organisms also have to break down macromolecules. They do this by ________________________________.
http://science.nhmccd.edu/biol/dehydrat/dehydrat.html and http://www.tvdsb.on.ca/westmin/science/sbioac/biochem/condense.htm
There are four categories of macromolecules in cells:
1. ______________________________
2. ______________________________
3. ______________________________
4. ______________________________
II. Carbohydrates
Carbohydrates include:
1. _________________________________________________________
2. _________________________________________________________
A. Monosaccharides
_______________________________ are simple sugars. The monosaccharides glucose and fructose are ______________________. They have the same formula, but the ____________ are arranged differently.
In aqueous solutions, monosaccharides form _______________.
B. Disaccharides
A disaccharide is a __________________ sugar. It is constructed by two ___________________________. Disaccharides are joined by ________________________.
The most common disaccharide is ________________________. It consists of _____________________ linked to a _______________________.
C. Polysaccharides
____________________________ carbohydrates are called polysaccharides. They are long chains of ______________________. They are polymers of ____________________________.
One familiar example of a polysaccharide is _____________________. Plant cells store starch for ____________________. Animals store excess sugar in the form of a polysaccharide called _________________________.
_______________________ is the most abundant organic compound on Earth. It forms cable-like fibrils in the tough walls that enclose ____________________. It is a major component of ___________________. It is also known as __________________________________.
Most animals cannot derive nutrition from fiber. Grazing animals survive on a diet of cellulose because they have ___________________________ in their digestive tracts that can break down cellulose.
Simple sugars and double sugars dissolve readily in water. They are ___________________________ are "water loving."
D. Low Carb Diets
Carbohydrate animation: http://www.wisc-online.com/objects/index.asp?objID=AP13104
III. Lipids
Lipids are ______________________. They do not mix with _________________. Examples:________________________________
A. Fats
Dietary fat consists largely of the molecule ________________________. Triglyceride is a combination of _______________________ and ____________________
http://www.tvdsb.on.ca/westmin/science/sbioac/biochem/triglyc.htm
Fats perform essential functions in the human body:
1. __________________________________
2. __________________________________
3. __________________________________
_______________________________ have less than the maximum number of hydrogens bonded to the carbons. ____________________________ have the maximum number of hydrogens bonded to the carbons.
Most animal fats have a high proportion of ____________________________ which can be unhealthy. Most plant oils tend to be low in __________________ fatty acids.
_______________________________: converting unsaturated fats to saturated fats by adding hydrogens. Creates _______________________ a type of unsaturated fat that is even more unhealthy than saturated fat.
B. Steroids
Steroids are very different from fats in ________________________ and ___________________________. The ___________________ skeleton is bent to form four fused rings. ____________________________ is the "base steroid" from which your body produces other steroids.
_______________________________ are controversial. They are variants of __________________________________.
Lipid animation: http://www.wisc-online.com/objects/index.asp?objID=AP13204
III. Proteins
A protein is a ___________________ constructed from __________________________ monomers.
Proteins perform most of the tasks that the body needs to function:
1. ____________________________________
2. ____________________________________
3. ____________________________________
4. ____________________________________
5. ____________________________________
6. ____________________________________
7. ____________________________________
8. ____________________________________
9. ____________________________________
10.___________________________________
A. The Monomers: Amino Acids
All proteins are constructed from a common set of ______________ kinds of amino acids.
Each amino acid consists of:
1. ___________________________________________
2. ___________________________________________
Amino acids and polypeptides: http://www.tvdsb.on.ca/westmin/science/sbioac/biochem/amino.htm
B. Proteins as Polymers
Cells link amino acids together by ____________________________________. The resulting bond between them is called a ____________________________.
The body has tens of thousands of different kinds of proteins. The _______________________ of amino acids make them different.
Primary Structure: _________________________________________________________. A slight change in the primary structure of a protein affects its ability to ______________________________.
C. Protein Shape
Proteins have four levels of structure:
1. ____________________________
2. ____________________________
3. ____________________________
4. ____________________________
Protein animation: http://www.wisc-online.com/objects/index.asp?objID=AP13304
D. What Determines Protein Structure?
A protein's shape is sensitive to its ____________________________________________. Unfavorable temperature or pH changes can cause the protein to unravel and lose its shape. This is called ________________________________.
IV. Nucleic Acids
Nucleic acids are _______________________________________ molecules. They provide the directions for building _______________________.
There are two types of nucleic acids:
1. ____________________
2. ____________________
The genetic instructions of DNA must be translated from the ________________________ to ___________________________.
Nucleic acids are polymers of _____________________________________.
Each DNA has one of the following nitrogen bases:
1. _____________________________
2. _____________________________
3. _____________________________
4. _____________________________
Nucleotide monomers are linked into long chains. These chains are called _____________________________ or _____________________. A _____________________ joins them together. Two strands of DNA form a _______________________________.
RNA, __________________________ is different from DNA. It has an extra _______________ group. It has the base __________________ instead of thymine.
V. Evolution Connection: DNA and Protein as Evolutionary Tape Measures
Molecular genealogy extends to relationships between ______________________/
Biologists use molecular analysis of DNA and protein sequences for testing _________________________________________.
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