Biology Chapter 3

Lesson 3.1 Chapter 3 Introduction (Reading)

·         Recall that carbon forms 4 strong covalent bonds.

·         Define hydrocarbons, isomers, and functional groups.

Hydrocarbons: Molecules consisting of only carbon and hydrogen

Functional Group: Molecular group attached to hydrocarbon that confers chemical properties or reactivates

Isomers: One of a group of molecules identical in atomic composition but different in structural arrangement

·         Identify various types of functional groups.

         Hydroxyl

         Carbonyl

          Carboxyl

                       Amino

·         List the different kinds of biological macromolecules.

Carbohydrates, Lipids, Nucleic Acid and Protein

·         Compare polymers and monomers.

Polymer: A molecule composed of many similar or identical molecules (Ex Starch)

Monomer: Smallest Chemical subunit of polymers (Monosaccharide)

·         Contrast dehydration and hydrolysis reactions.

Dehydration reaction: Type of chemical reaction in which two moles join to form one larger molecule simultaneously splitting out a molecule of H2O

             Hydrolysis: A molecule of water is added instead of removed

Lesson 3.2 Chemical Building Blocks of Life – Carbon

·         Define organic chemistry and identify organic compounds.

Organic Chemistry: The study of compounds that contain carbons and hydrogens

·         Explain how the number of valence electrons in carbon determines the number of covalent bonds it can form.

Carbon has 4 valence electrons meaning it can form four covalent bonds

·         Explain how carbon bonding can lead to molecular diversity, i.e. how can carbon chains vary in structure?

Varying in length

Varying in Branching

Varying in double bond position

Varying in presences of rings

·         Define hydrocarbons and identify an example.

Hydrocarbon: Molecules consisting of only carbons and hydrogens

·         Define functional groups and identify the seven most important functional groups for life.

Are specific groups of atoms attached to carbon skeletons that determine the chemical properties

Hydroxyl

Carbonyl

Carboxyl

Amino

Sulfhydryl

Phosphate

Methyl

         Identify functional groups given their chemical structure.

·         Hydroxyl OH

·         Carbonyl   C double bonded O

·         Carboxyl COOH

·         Amino NH2

·         Sulfhydryl SH

·         Phosphate PO4

·         Methyl CH3

Define isomer and provide examples of the three different types.

Structural Isomers- Differ in the arrangement of atoms (Pentane vs isopentane)

Cis Trans Isomers in Spatial arrangement due to the double bond

Enantiomers Mirror image molecules (L albuterol vs D albuterol)

Lesson 3.3 Chemical Building Blocks of Life – Carbohydrates

·         Identify the four classes of macromolecules important for life.

Carbohydrates, Nucleic Acids, Proteins, Lipids

·         Explain the processes by which polymers are assembled from monomers and disassembled.

Dehydration reactions: are chemical reactions in which monomers are joined together to form a polymer, or they are being assembled in which water is removed in the process

              Hydrolysis Reaction: A polymer is broken down into monomers by adding water In the             process so being disassembled

·         Describe the structures and functions of simple and complex carbohydrates.

Monosaccharides: Single sugar molecule example glucose

Disaccharides: Formed when a reaction is joins two monosaccharides covalently bond called glycosidic linkage Ex: Glucose + Fructose=Sucrose

Polysaccharides: Long chains of monosaccharides linked with dehydration synthesis

Starch energy storage in plants

Glycogen storage polysaccharides in animals

Cellulose: Component of tough wall of plants cells

Lesson 3.4 Chemical Building Blocks of Life – Nucleic Acids

·         Identify the four classes of macromolecules important for life.

·         Compare and contrast the structures of DNA and RNA and their component nucleotides.

DNA: is a deoxyribose with an H, Double Stranded, ATCG, Stores genetic information

RNA: is a ribose with an OH, Single Stranded, AUCG, helps in gene expression and protein synthesis

·         Identify the nitrogenous bases and sugars of DNA and RNA.

                         DNA contains ACTG and    RNA contains AUGC

                               Pyrimidines is CUT and Purines is AG

Lesson 3.5 Chemical Building Blocks of Life – Proteins

·         Identify the four classes of macromolecules important for life.

·         List the main functions of proteins.

Enzymatic protein, Structural Protein, Storage protein, Transport protein hormonal protein, receptor protein, defensive protein

·         Describe the structures of amino acids.

An Amino group NH2

Central alpha carbon

Hydrogen Atom

Variable side chain

·         Describe the four levels of protein structure.

Primary Structure unique structure of amino acid

Secondary: Alpha helix, beta pleated sheet, results from hydrogen bonds between polar groups

Tertiary Structure results from the bending and folding of a polypeptide chain that occurs due to a variety of interactions

Quaternary structure: Only found in proteins composed of more than one polypeptide chain

·         Define motifs and domains.

Motifs: Common element of secondary structure seen in polypeptides useful in determining the function of unknown properties

Domain: Functional group within a larger structure

             Describe the function of protein chaperonins.

Helps proteins fold correctly they prevent misfolding aggregation

·         Define denaturation as it relates to protein structure.

Protein loses structure and function due to environmental conditions

Lesson 3.6 Chemical Building Blocks of Life – Lipids

·         Identify the four classes of macromolecules important for life.

·         Describe why lipids are not a true polymer.

Because they are not composed of repeating monomeric subunits. Instead they are composed of distinct molecules such as fatty acids

·          

·         Describe the structure of triglycerides.

Composed of 3 fatty acids joined to a glycerol

·         Distinguish between saturated and unsaturated fats.

Saturated fats: Contain no double bonds between the atoms and typically solid at room temp

Unsaturated fats do contain double bonds

·         Describe the structure of phospholipids.

Glycerol is with 2 fatty acid tails and a phosphate group

·         Define amphipathic and how it relates to phospholipids.

Contain hydrophobic and hydrophilic region relates to phospholipids as the fatty acid’s tails are hydrophobic and the heads are hydrophilic

·         Describe the structure of micelles and phospholipid bilayers and why they form in water.

Micelles: Spherical structures where phospholipid molecules arrange themselves with their hydrophilic head  facing outwards towards the water

·         Identify the functions of the different types of lipids.

Triglycerides: Stores energy

Phospholipids: Form cellular membranes and structural integrity

Steroids: Serves as precursors for hormones

Study Guide: Chemical Building Blocks of Life

1. Introduction to Organic Molecules

• Carbon Bonds: Carbon forms 4 strong covalent bonds.

• Key Definitions:

  • Hydrocarbons: Molecules with only carbon and hydrogen.

  • Functional Groups: Molecular groups that confer chemical properties.

  • Isomers: Molecules with identical atomic composition but different structural arrangements.

2. Types of Functional Groups

• Hydroxyl

• Carbonyl

• Carboxyl

• Amino

• Additional functional groups: Sulfhydryl, Phosphate, Methyl.

3. Biological Macromolecules

• Four Classes: Carbohydrates, Lipids, Nucleic Acids, Proteins.

4. Polymers vs Monomers

• Polymer: A large molecule composed of many similar units (e.g., Starch).

• Monomer: The smallest chemical subunit of polymers (e.g., Monosaccharide).

5. Chemical Reactions

• Dehydration Reaction: Two moles join to form a larger molecule, removing H2O.

• Hydrolysis Reaction: Water is added to break a polymer into monomers.

6. Carbon and Molecular Diversity

• How carbon chains can vary:

  • Length

  • Branching

  • Double bond position

  • Presence of rings

7. Macromolecules & Carbohydrates

• Classes of Macromolecules: Carbohydrates, Nucleic Acids, Proteins, Lipids.

• Carbohydrate Structures:

  • Monosaccharides: Single sugar molecules (e.g., Glucose).

  • Disaccharides: Two monosaccharides (e.g., Sucrose).

  • Polysaccharides: Long chains (e.g., Starch, Glycogen, Cellulose).

8. Nucleic Acids

• DNA vs RNA:

  • DNA: Double-stranded, stores genetic info (ATCG).

  • RNA: Single-stranded, aids in gene expression (AUCG).

9. Proteins

• Functions: Enzymatic, Structural, Storage, Transport, Hormonal, Receptor, Defensive.

• Amino Acids Structure: Amino group, Central carbon, Hydrogen atom, Variable side chain.

• Levels of Protein Structure:

  • Primary: Sequence of amino acids

  • Secondary: Alpha helix and beta pleated sheet due to hydrogen bonds

  • Tertiary: Folding due to various interactions

  • Quaternary: Multiple polypeptide chains.

10. Lipids

• Why Not True Polymers: Composed of distinct molecules (e.g., fatty acids).

• Triglycerides: Three fatty acids + glycerol.

• Phospholipids: Glycerol + 2 fatty acids + phosphate group.

• Functions of Lipids:

  • Storage (Triglycerides)

  • Membrane formation (Phospholipids)

  • Hormone precursors (Steroids).