Chapter 3 Biochemistry Modern Biology Textbook Holt

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Chapter 3 BiochemistryModern Biology
TextbookHolt
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Objectives
Section 1 Carbon Compounds
Chapter 3

• Distinguish between organic and inorganic
  compounds.
• Explain the importance of carbon bonding in
  biological molecules.
• Identify functional groups in biological
  molecules.
• Summarize how large carbon molecules are
  synthesized and broken down.
• Describe how the breaking down of ATP supplies
  energy to drive chemical reactions.

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Carbon Bonding
Section 1 Carbon Compounds
Chapter 3

• The study of carbon-based molecules is called
  organic chemistry
• Organic compounds contain carbon atoms and are
  found in living things.
• Most inorganic compounds do not contain carbon
  atoms.

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Carbon Bonding, continued
Section 1 Carbon Compounds
Chapter 3

• Carbon has 4
• electrons in its outer
• shell
• So it readily forms
• 4 covalent bonds

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Organic Molecules

• Hydrocarbons are the simplest organic molecule
  that contain only carbon and hydrogen (for
  example, methane, CH4)
• Methane is one of the most abundant hydrocarbons
  in natural gas
• formed by bacteria that live in swamps and
  intestines of grazing animals like cows
• Larger hydrocarbons, like octane (8 carbons) are
  found in gasoline that we use in cars

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Functional Groups
Section 1 Carbon Compounds
Chapter 3

• Functional groups are groups of atoms that
  influence the properties of molecules and the
  chemical reactions in which the molecules
  participate.
• Condensation reactions join monomers (small
  simple molecules) to form polymers. A
  condensation reaction releases water as a
  by-product.
• In a hydrolysis reaction, water is used to split
  polymers into monomers.

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Large Carbon Molecules

• Many carbon compounds
• Monomers
• Polymers
• Macromolecules
• Ex carbohydrates, lipids, protein and nucleic
  acid

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Polymer Example
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Energy Currency
Section 1 Carbon Compounds
Chapter 3

• Adenosine triphosphate (ATP) stores and releases
  energy during cell processes, enabling organisms
  to function.

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Section 2 Molecules of Life
Chapter 3
Objectives

• Distinguish between monosaccharides,
  disaccharides,and polysaccharides.
• Explain the relationship between amino acids and
  protein structure.
• Describe the induced fit model of enzyme action.
• Compare the structure and function of each of the
  different types of lipids.
• Compare the nucleic acids DNA and RNA.

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Carbohydrates
Section 2 Molecules of Life
Chapter 3

• Carbohydrates are organic compounds composed of
  carbon, hydrogen, and oxygen in a ratio of
• 1 carbon 2 hydrogen 1 oxygen
• Carbohydrates are a source of energy and are used
  as structural materials in organisms.

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Carbohydrates, continued
Section 2 Molecules of Life
Chapter 3

• Monosaccharides
• Carbohydrates are made up of monomers called
  monosaccharides.
• Ex fructose the sugar found in fruit
• Disaccharides and Polysaccharides
• Two monosaccharides join to form a double sugar
  called a disaccharide.
• A complex sugar, or polysaccharide, is made of
  three or more monosaccharides.

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Proteins
Section 2 Molecules of Life
Chapter 3

• Proteins are organic compounds composed mainly of
  carbon, hydrogen, oxygen, and nitrogen.
• Many structures such as hair and horns are made
  of proteins
• Also skin and muscles

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Proteins

• Most elaborate molecule on earth
• There are tens of thousands of different types of
  proteins in the body each has a specific
  structure and function
• 4 types of protein
• Structural provide support ( hair, connective
  tissue)
• Storage provide amino acid source (eggs)
• Contractile allow for muscle contraction
• Transport allow for oxygen to be transported
  through the body (hemoglobin RBC)

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Proteins, continued
Section 2 Molecules of Life
Chapter 3

• Amino Acids
• Proteins are made up of monomers called amino
  acids. The sequence of amino acids determines a
  proteins shape and function.
• Dipeptides and Polypeptides
• Two amino acids are joined by peptide bonds to
  form a dipeptide.
• A long chain of amino acids is called a
  polypeptide.

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Enzyme Activity
Section 2 Molecules of Life
Chapter 3

• Enzymes speed up chemical reactions and bind to
  specific substrates.

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Lipids
Section 2 Molecules of Life
Chapter 3

• Lipids are nonpolar molecules that store energy,
  but are slow to burn and are an important part of
  cell membranes.
• Fats are stored in adipose tissue, for energy
  reserve and protection for vital organs

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Lipids, continued
Section 2 Molecules of Life
Chapter 3

• Fatty Acids
• Most lipids contain fatty acids, unbranched
  carbon molecules that have a hydrophilic (water
  loving)end and a hydrophobic (water fearing)
  end.
• Triglycerides
• Triglycerides consist of three fatty acids and
  one molecule of glycerol.

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Lipids, continued
Section 2 Molecules of Life
Chapter 3

• Phospholipids
• Phospholipids, which make up cell membranes,
  consist of two fatty acids and one glycerol
  molecule.
• Waxes
• A wax is made of one long fatty acid chain joined
  to one long alcohol.
• Waterproof and in plants
• forms a protective coating

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Lipids, continued

• Steroids are classified as lipids because they
  are hydrophilic, but they are very different
  structurally and functionally
• Steroids
• Cholesterol is steroid used to make other
  steroids
• Ex testosterone, estrogen
• Anabolic steroids are a synthetic version of
  testosterone - used as a performance enhancing
  drug

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Structure of Nucleic Acids
Section 2 Molecules of Life
Chapter 3

• A nucleic acid is a large and complex organic
  molecule that stores and transports information.
• Ex Deoxyribonucleic Acid (DNA) contains
  genetic activity

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Section 2 Molecules of Life
Chapter 3
DNA Overview
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Multiple Choice
Standardized Test Prep
Chapter 3

• 1. Which of the following is not a function of
  polysaccharides?
• A. energy source
• B. energy storage
• C. structural support
• D. storage of genetic information

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Multiple Choice, continued
Standardized Test Prep
Chapter 3

• 2. Which of the following statements is false?
• F. A wax is a lipid.
• G. Starch is a lipid.
• H. Saturated fats are solid at room temperature.
• J. Unsaturated fats are liquid at room
  temperature.

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Multiple Choice, continued
Standardized Test Prep
Chapter 3

• 3. Which of the following molecules stores
  hereditary information?
• A. ATP
• B. DNA
• C. protein
• D. carbohydrates

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Multiple Choice, continued
Standardized Test Prep
Chapter 3

• 4. What is the name of the molecule in plants
  that stores sugars?
• F. starch
• G. protein
• H. cellulose
• J. glycogen

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Chapter 3
Standardized Test Prep
Multiple Choice, continued
5. Which of the following molecules make up the
basic structure of a cell membrane? A. waxes B.
steroids C. fatty acids D. phospholipids
The figure below illustrates the basic structure
of a cell membrane. Use the figure to answer the
questions that follow.
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Chapter 3
Standardized Test Prep
Multiple Choice, continued
6. The tails of the molecules in the figure
orient away from water. Which of the following
describes the tails movement away from
water? F. polar G. adhesive H. hydrophilic J.
hydrophobic
The figure below illustrates the basic structure
of a cell membrane. Use the figure to answer the
questions that follow.
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Chapter 3
Standardized Test Prep
Multiple Choice, continued
7. simple sugars carbohydrates amino acids
A. lipids B. proteins C. nucleic acids D.
amino acids
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Chapter 3
Standardized Test Prep
Multiple Choice, continued
8. What is the name of the functional group
circled in the structural formula? F. amino G.
hydroxyl H. phosphate J. carboxyl
The figure below represents the structural
formula of a molecule. Use the figure to answer
the question that follows.
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Chapter 3
Standardized Test Prep
Short Response, continued
Proteins are affected by environmental
conditions such as heat and pH. Explain why the
process of cooking an egg cannot be
reversed. Answer The heat that is added to
the egg changes the bonds in the proteins and
other molecules that make up the egg to such a
large extent that the original protein shape can
no longer be distinguished.
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Chapter 3
Standardized Test Prep
Extended Response
Enzymes are essential for the functioning of all
cells. Part A Explain what enzymes do that is
essential for cell function. Part B Explain the
induced fit model of enzyme action. Answer Part
A Enzymes catalyze chemical reactions that are
involved in important cell processes. Part B
Bonding of the substrates to enzymes causes a
slight change in the enzymes shape, thereby
weakening some of the bonds and lowering
activation energy.