p.1
Carbon as the Framework of Biological Molecules
How many covalent bonds can carbon form?
Up to four covalent bonds.
p.1
Carbon as the Framework of Biological Molecules
What are hydrocarbons?
Molecules consisting only of carbon and hydrogen.
p.7
Proteins: Structure, Function, and Folding
What is the primary structure of a protein?
The sequence of amino acids.
p.3
Carbohydrates: Structure and Function
What are some examples of carbohydrates?
Sugars, starch, glucose, cellulose, and chitin.
p.9
Lipids: Structure and Hydrophobic Properties
What is the main chemical characteristic of lipids?
They are insoluble in water.
p.7
Proteins: Structure, Function, and Folding
What are domains in proteins?
Functional units within a larger structure, with most proteins made of multiple domains performing different parts of the protein’s function.
p.4
Carbohydrates: Structure and Function
What are polysaccharides composed of?
Long chains of monosaccharides linked through dehydration synthesis.
p.3
Biological Macromolecules: Carbohydrates, Proteins, Nucleic Acids, and Lipids
What is hydrolysis?
The breakdown of large molecules by the addition of water, breaking polymers down to monomers.
p.6
Energy Storage and Metabolism in Biological Molecules
What is the primary energy currency of the cell?
Adenosine triphosphate (ATP).
p.3
Isomers: Structural and Stereoisomers
What distinguishes fructose and galactose from glucose?
Fructose is a structural isomer, and galactose is a stereoisomer of glucose.
p.8
Protein Denaturation and Chaperones
Describe the structure of a chaperonin from the GroE family.
It is barrel-shaped, composed of two identical rings with seven identical subunits, each having three distinct domains.
p.6
Proteins: Structure, Function, and Folding
What is the structure of an amino acid?
A central carbon atom, an amino group, a carboxyl group, a single hydrogen, and a variable R group.
p.10
Carbohydrates: Structure and Function
Why can't cellulose be used as an energy source?
Because starch and glycogen have similar structures, but cellulose does not.
p.1
Functional Groups and Their Properties
What is the difference between an aldehyde and a ketone?
An aldehyde is a carbonyl group at one end of the molecule, while a ketone is located anywhere else within the molecule.
p.5
Nucleic Acids: Structure and Information Storage
What does it mean for DNA strands to be antiparallel?
The backbones run in opposite 5' → 3' directions.
p.6
Proteins: Structure, Function, and Folding
What are the functions of proteins?
Enzyme catalysis, defense, transport, support, motion, regulation, and storage.
p.5
Nucleic Acids: Structure and Information Storage
What are the two types of sugars found in nucleotides?
Ribose sugar and deoxyribose sugar.
p.5
Nucleic Acids: Structure and Information Storage
What is the structure of DNA?
A double helix formed by two polynucleotide strands connected by hydrogen bonds.
p.1
Isomers: Structural and Stereoisomers
What is an isomer?
Molecules with the same molecular or empirical formula.
p.5
Nucleic Acids: Structure and Information Storage
How does RNA differ from DNA?
RNA contains ribose instead of deoxyribose and uracil instead of thymine, and it is a single polynucleotide strand.
p.6
Energy Storage and Metabolism in Biological Molecules
What role do NAD+ and FAD+ play in cellular reactions?
They are electron carriers for many cellular reactions.
p.3
Carbohydrates: Structure and Function
What are disaccharides?
Two monosaccharides linked together by dehydration synthesis, used for sugar transport or energy storage.
p.8
Protein Denaturation and Chaperones
How does a chaperonin assist in protein refolding?
It changes the chamber from hydrophobic to hydrophilic using energy from ATP hydrolysis.
p.6
Proteins: Structure, Function, and Folding
How are amino acids joined together?
By dehydration synthesis to form peptide bonds.
p.6
Proteins: Structure, Function, and Folding
What is a peptide bond?
A covalent bond formed between the positive amino group and the negative carboxyl group of two adjacent amino acids.
p.9
Lipids: Structure and Hydrophobic Properties
What roles do steroids play in biological systems?
They are important in membranes and as the basis for hormones involved in chemical signaling.
p.4
Nucleic Acids: Structure and Information Storage
What are the nitrogenous bases in nucleic acids?
Purines: adenine and guanine; Pyrimidines: thymine, cytosine, uracil.
p.3
Carbohydrates: Structure and Function
What is the empirical formula for carbohydrates?
C(H2O)n, indicating a 1:2:1 molar ratio of carbon, hydrogen, and oxygen.
p.7
Proteins: Structure, Function, and Folding
What is the quaternary structure of a protein?
The arrangement of individual chains (subunits) in a protein with two or more polypeptide chains.
p.6
Proteins: Structure, Function, and Folding
What are proteins composed of?
One or more long, unbranched chains of amino acids.
p.10
Lipids: Structure and Hydrophobic Properties
In a phospholipid bilayer, which direction do the hydrophilic heads point?
Outward, toward the water.
p.2
Isomers: Structural and Stereoisomers
What are D and L forms of sugars?
Examples of enantiomers found in living organisms.
p.10
Lipids: Structure and Hydrophobic Properties
What aspect of triglyceride structure accounts for their insolubility in water?
The nonpolar C—H bonds in fatty acids.
p.6
Proteins: Structure, Function, and Folding
What are the special-function amino acids known for?
They have chemical properties that allow them to help form links between proteins.
p.4
Nucleic Acids: Structure and Information Storage
What sugars are found in DNA and RNA?
Deoxyribose in DNA and ribose in RNA.
p.2
Isomers: Structural and Stereoisomers
What are structural isomers?
Isomers that differ in the structure of the carbon skeleton.
p.2
Isomers: Structural and Stereoisomers
What are stereoisomers?
Isomers that differ in how groups are attached or arranged in space.
p.8
Protein Denaturation and Chaperones
What role do chaperone proteins play in protein folding?
They help proteins fold correctly.
p.9
Lipids: Structure and Hydrophobic Properties
What causes lipids to be hydrophobic?
A high proportion of nonpolar C—H bonds.
p.10
Lipids: Structure and Hydrophobic Properties
What do lipids spontaneously form in water?
Micelles or lipid bilayers.
p.4
Carbohydrates: Structure and Function
What are the two main functions of polysaccharides?
Energy storage and structural support.
p.9
Lipids: Structure and Hydrophobic Properties
What are phospholipids composed of?
One glycerol, two fatty acids, and a phosphate group.
p.1
Carbon as the Framework of Biological Molecules
What types of atoms can carbon bond with?
Oxygen (O), Nitrogen (N), Sulfur (S), Phosphorus (P), or Hydrogen (H).
p.2
Isomers: Structural and Stereoisomers
What are isomers?
Molecules with the same molecular or empirical formula.
p.5
Nucleic Acids: Structure and Information Storage
What are the base-pairing rules in DNA?
A pairs with T (or U in RNA) with 2 hydrogen bonds, and C pairs with G with 3 hydrogen bonds.
p.7
Proteins: Structure, Function, and Folding
What is the tertiary structure of a protein?
The final folded shape of a globular protein, stabilized by various forces.
p.7
Proteins: Structure, Function, and Folding
What are motifs in protein structure?
Common elements of secondary structure seen in many polypeptides, useful for determining the function of unknown proteins.
p.8
Protein Denaturation and Chaperones
What happens to proteins in cystic fibrosis despite having the correct amino acid sequence?
They fail to fold correctly.
p.9
Lipids: Structure and Hydrophobic Properties
What distinguishes saturated fats from unsaturated fats?
Saturated fats have no double bonds between carbon atoms, while unsaturated fats contain one or more double bonds.
p.10
Lipids: Structure and Hydrophobic Properties
What is a triglyceride composed of?
Fatty acids and glycerol.
p.6
Proteins: Structure, Function, and Folding
What characterizes nonpolar amino acids?
They have —CH2 or —CH3 in their R groups.
p.9
Lipids: Structure and Hydrophobic Properties
What are terpenes and where are they found?
Terpenes are found in biological pigments, such as chlorophyll and retinal.
p.3
Biological Macromolecules: Carbohydrates, Proteins, Nucleic Acids, and Lipids
What is dehydration synthesis?
The formation of large molecules by the removal of water, joining monomers to form polymers.
p.2
Isomers: Structural and Stereoisomers
Give an example of structural isomers.
Glucose (aldose) and fructose (ketose), both C6H12O6.
p.1
Isomers: Structural and Stereoisomers
What does the empirical formula represent?
The simplest ratio of elements present in a compound.
p.5
Nucleic Acids: Structure and Information Storage
What is the function of RNA in relation to DNA?
RNA uses information in DNA to specify the sequence of amino acids in proteins.
p.10
Lipids: Structure and Hydrophobic Properties
What is the structure of a phospholipid?
Phospholipids have a polar (hydrophilic) head and nonpolar (hydrophobic) tails.
p.3
Carbohydrates: Structure and Function
What are some examples of disaccharides?
Sucrose (glu-fru), lactose (glu-gal), and maltose (glu-glu).
p.8
Protein Denaturation and Chaperones
What is denaturation in proteins?
The loss of structure and function due to environmental conditions.
p.8
Protein Denaturation and Chaperones
What environmental factors can cause protein denaturation?
pH, temperature, and ionic concentration of the solution.
p.2
Biological Macromolecules: Carbohydrates, Proteins, Nucleic Acids, and Lipids
What is a polymer?
A macromolecule built by linking monomers.
p.1
Functional Groups and Their Properties
What are functional groups?
Specific molecular groups that bond to carbon-hydrogen cores and have unique chemical properties.
p.7
Proteins: Structure, Function, and Folding
What characterizes the secondary structure of a protein?
Interactions of groups in the peptide backbone, forming helices and sheets.
p.3
Carbohydrates: Structure and Function
What are monosaccharides?
The simplest carbohydrates, some with as few as 3 carbons, but 6-carbon sugars (hexoses) are particularly important.
p.2
Isomers: Structural and Stereoisomers
What are enantiomers?
Stereoisomers that are mirror images of each other.
p.9
Lipids: Structure and Hydrophobic Properties
What are triglycerides composed of?
One glycerol and three fatty acids.
p.2
Isomers: Structural and Stereoisomers
What does it mean for a carbon to be chiral?
It is bound to four different groups.
p.2
Biological Macromolecules: Carbohydrates, Proteins, Nucleic Acids, and Lipids
What are biological macromolecules?
Carbohydrates, nucleic acids, proteins, and lipids.
p.9
Lipids: Structure and Hydrophobic Properties
What is the origin and melting point of saturated fats?
Higher melting point and of animal origin.
p.10
Proteins: Structure, Function, and Folding
What influences the overall structure of a protein the most?
The R group of the amino acid.
p.4
Carbohydrates: Structure and Function
How are the glucose molecules in cellulose linked?
By β-(1 → 4) glycosidic bonds.
p.8
Protein Denaturation and Chaperones
What is the result of denaturation?
Proteins change from a folded to an unfolded state.
p.2
Biological Macromolecules: Carbohydrates, Proteins, Nucleic Acids, and Lipids
What is a monomer?
A small, similar chemical subunit.
p.9
Lipids: Structure and Hydrophobic Properties
Why are phospholipids considered amphipathic?
Because they have both hydrophilic (polar head) and hydrophobic (nonpolar tails) regions.
