Questions and Answers
What are carbohydrates?
Carbohydrates
Which of the following is not a polymer?
What is the chemical reaction mechanism by which cells make polymers from monomers?
How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
Signup and view all the answers
Which of the following is an exception to the statement that large organic molecules are usually assembled by polymerization of a few kinds of simple subunits?
Signup and view all the answers
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Signup and view all the answers
Polysaccharides, triacylglycerides, and proteins are similar in that they:
Signup and view all the answers
Dehydration reactions are used in forming which of the following compounds?
Signup and view all the answers
DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?
Signup and view all the answers
Which of the following polymers contain nitrogen?
Signup and view all the answers
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
Signup and view all the answers
The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down?
Signup and view all the answers
On food packages, to what does the term insoluble fiber refer?
Signup and view all the answers
A molecule with the chemical formula is probably a:
Signup and view all the answers
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
Signup and view all the answers
All of the following are polysaccharides except:
Signup and view all the answers
Which of the following is true of both starch and cellulose?
Signup and view all the answers
Which of the following is true of cellulose?
Signup and view all the answers
Humans can digest starch but not cellulose because:
Signup and view all the answers
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA:
Signup and view all the answers
If cells are grown in a medium containing radioactive 32P-labeled phosphate, which of these molecules will be labeled?
Signup and view all the answers
How will brief heating (to 95°C) affect macromolecular structures in aqueous solution?
Signup and view all the answers
If cells are grown in a medium containing radioactive 15N, which of these molecules will be labeled?
Signup and view all the answers
Which of the following is not a monomer/polymer pairing?
Signup and view all the answers
Among biological polymers, which has the least structural variety?
Signup and view all the answers
Approximately 32 different monomeric carbohydrate subunits are found in various natural polysaccharides. Proteins are composed of 20 different amino acids. Which class of biological polymer has the greatest functional variety?
Signup and view all the answers
Which class of biological polymer has the greatest information-coding capacity?
Signup and view all the answers
Which of the following statements concerning saturated fats is not true?
Signup and view all the answers
A molecule with the formula C18H36O2 is probably a:
Signup and view all the answers
Which of the following statements is true for the class of biological molecules known as lipids?
Signup and view all the answers
The label on a container of margarine lists 'hydrogenated vegetable oil' as the major ingredient. What is the result of adding hydrogens to vegetable oil?
Signup and view all the answers
Which of the following is true regarding saturated fatty acids?
Signup and view all the answers
Why are human sex hormones considered to be lipids?
Signup and view all the answers
All of the following contain amino acids except:
Signup and view all the answers
The bonding of two amino acid molecules to form a larger molecule requires:
Signup and view all the answers
There are 20 different amino acids. What makes one amino acid different from another?
Signup and view all the answers
Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?
Signup and view all the answers
How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids?
Signup and view all the answers
Which bonds are created during the formation of the primary structure of a protein?
Signup and view all the answers
What maintains the secondary structure of a protein?
Signup and view all the answers
Which level of protein structure do the α helix and the β pleated sheet represent?
Signup and view all the answers
Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins?
Signup and view all the answers
The amino acids of the protein keratin are arranged predominantly in an α helix. This secondary structure is stabilized by:
Signup and view all the answers
The tertiary structure of a protein is the:
Signup and view all the answers
What type of covalent bond between amino acid side chains (R groups) functions in maintaining a polypeptide's specific three-dimensional shape?
Signup and view all the answers
At which level of protein structure are interactions between the side chains (R groups) most important?
Signup and view all the answers
The R group or side chain of the amino acid serine is -CH2-OH. The R group or side chain of the amino acid leucine is -CH2-CH(CH3)2. Where would you expect to find these amino acids in a globular protein in aqueous solution?
Signup and view all the answers
Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides?
Signup and view all the answers
Changing a single amino acid in a protein consisting of 325 amino acids would:
Signup and view all the answers
Humans and mice differ because:
Signup and view all the answers
Molecules with which functional groups may form polymers via dehydration reactions?
Signup and view all the answers
Which of these molecules is not formed by dehydration reactions?
Signup and view all the answers
Which of these classes of biological molecules consist of both small molecules and macromolecular polymers?
Signup and view all the answers
Which of the following is not a polymer?
Signup and view all the answers
What is the chemical reaction mechanism by which cells make polymers from monomers?
Signup and view all the answers
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Signup and view all the answers
Which of the following polymers contain nitrogen?
Signup and view all the answers
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
Signup and view all the answers
The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the 'a' form. Which of the following could amylase break down?
Signup and view all the answers
On food packages, to what does the term insoluble fiber refer?
Signup and view all the answers
A molecule with the chemical formula C6H12O6 is probably a?
Signup and view all the answers
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
Signup and view all the answers
All of the following are polysaccharides except:
Signup and view all the answers
Which of the following is true of both starch and cellulose?
Signup and view all the answers
Which of the following is true of cellulose?
Signup and view all the answers
Humans can digest starch but not cellulose because:
Signup and view all the answers
Which of the following statements concerning saturated fats is not true?
Signup and view all the answers
A molecule with the formula C18H36O2 is probably a:
Signup and view all the answers
Which of the following statements is true for the class of biological molecules known as lipids?
Signup and view all the answers
The label on a container of margarine lists 'hydrogenated vegetable oil' as the major ingredient. What is the result of adding hydrogens to vegetable oil?
Signup and view all the answers
Which of the following is true regarding saturated fatty acids?
Signup and view all the answers
Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement?
Signup and view all the answers
Which modifications of fatty acids will best keep triglycerides solid at warmer temperatures?
Signup and view all the answers
Why are human sex hormones considered to be lipids?
Signup and view all the answers
All of the following contain amino acids except:
Signup and view all the answers
The bonding of two amino acid molecules to form a larger molecule requires:
Signup and view all the answers
There are 20 different amino acids. What makes one amino acid different from another?
Signup and view all the answers
The bonding of two amino acid molecules to form a larger molecule requires which of the following?
Signup and view all the answers
Polysaccharides, triacylglycerides, and proteins are similar in that they:
Signup and view all the answers
Dehydration reactions are used in forming which of the following compounds?
Signup and view all the answers
What aspects of protein structure are stabilized or assisted by hydrogen bonds?
Signup and view all the answers
Which bonds are created during the formation of the primary structure of a protein?
Signup and view all the answers
What maintains the secondary structure of a protein?
Signup and view all the answers
Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins?
Signup and view all the answers
Which level of protein structure do the α helix and the β pleated sheet represent?
Signup and view all the answers
The amino acids of the protein keratin are arranged predominantly in an α helix. This secondary structure is stabilized by:
Signup and view all the answers
The tertiary structure of a protein is the:
Signup and view all the answers
Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides?
Signup and view all the answers
What methods may be used to elucidate the structures of purified proteins?
Signup and view all the answers
In a normal cellular protein, where would you expect to find a hydrophobic amino acid like valine?
Signup and view all the answers
Which of the following techniques uses the amino acid sequences of polypeptides to predict a protein's three-dimensional structure?
Signup and view all the answers
One of the primary functions of RNA molecules is to:
Signup and view all the answers
Which of the following descriptions best fits the class of molecules known as nucleotides?
Signup and view all the answers
Which of the following are nitrogenous bases of the pyrimidine type?
Signup and view all the answers
Which of the following are nitrogenous bases of the purine type?
Signup and view all the answers
Which of the following is an example of hydrolysis?
Signup and view all the answers
Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA?
Signup and view all the answers
Molecules with which functional groups may form polymers via dehydration reactions?
Signup and view all the answers
Which of these molecules is not formed by dehydration reactions?
Signup and view all the answers
Study Notes
Biological Molecules and Reactions
- Humans and mice differ in nucleotide sequences of nucleic acids.
- Polymers can be formed via dehydration reactions involving hydroxyl or carboxyl groups.
- Fatty acids are not formed through dehydration reactions—this applies to DNA, proteins, and disaccharides.
Bio-macromolecule Classes
- Carbohydrates consist of small molecules and macromolecular polymers, unlike lipids, proteins, and nucleic acids which consist only of macromolecular polymers.
- Glucose is not a polymer, whereas starch, chitin, cellulose, and DNA are.
- Dehydration reactions are responsible for forming polymers from monomers.
Enzymatic and Digestive Processes
- Amylase specifically breaks down glycogen due to its ability to hydrolyze "a" glycosidic linkages, unlike cellulose which contains "b" linkages.
- Insoluble fiber on food packages refers to cellulose.
- Humans digest starch but not cellulose because they lack enzymes to hydrolyze the "b" linkages of cellulose.
Fatty Acids and Lipids
- Saturated fats contain no double bonds between carbon atoms and are more common in animal products.
- Hydrogenated vegetable oils result in products that stay solid at room temperature.
- Fatty acids characterized by the formula C18H36O2 are classified as fats.
Protein Structure
- Proteins are formed by the bonding of amino acids through peptide bonds. This process requires the release of a water molecule.
- Hydrogen bonds stabilize the secondary, tertiary, and quaternary structures of proteins.
- The secondary structure includes "a" helices and "b" pleated sheets, maintained by hydrogen bonds.
Protein Function and Interactions
- Misfolded polypeptides can lead to diseases such as Alzheimer's and Parkinson's.
- The tertiary structure of proteins is the unique three-dimensional shape achieved by the folding of the polypeptide chain.
- Hydrophobic amino acids typically reside in the interior of proteins, away from water, or can be found in transmembrane regions.
Nucleotides and Nucleic Acids
- Nucleotides consist of a nitrogenous base, a phosphate group, and a pentose sugar.
- Pyrimidine nitrogenous bases include cytosine and uracil, while purine bases are adenine and guanine.
- RNA molecules function in protein synthesis and are vital for cellular activities.
Hydrolysis and Dehydration Reactions
- Hydrolysis involves the addition of water to break down macromolecules, contrasting with dehydration reactions that build polymers.
- To completely hydrolyze a polymer with 11 monomers, 10 molecules of water are required.
Techniques for Structural Elucidation
- X-ray crystallography and NMR spectroscopy (nuclear magnetic resonance) are techniques used to determine the three-dimensional structures of proteins.
- Bioinformatics can predict protein structures based on amino acid sequences.
General Characteristics and Functions
- Large organic molecules like polysaccharides, triacylglycerides, and proteins are typically synthesized from subunits through dehydration reactions.
- Enzymes are crucial for catalyzing reactions involving the formation or breakdown of macromolecules.### Biological Molecules and Reactions
- Macromolecules like proteins, polysaccharides, and triacylglycerides are synthesized from subunits through dehydration reactions.
- Peptide bonds form between monomers, making proteins unique and essential.
- Polymers such as starch and cellulose consist of glucose, while chitin contains nitrogen in its structure.
Enzymatic Reactions
- DNAase hydrolyzes phosphodiester bonds in DNA, initially breaking connections between deoxyribose sugars.
- Amylase specifically breaks down starch, which contains α glycosidic linkages, whereas it cannot digest cellulose, which has β linkages.
Carbohydrates and Polysaccharides
- Lactose is classified as a disaccharide consisting of glucose and galactose.
- Lactose is distinct from polysaccharides like chitin, glycogen, and amylopectin; only chitin contains nitrogen.
- The molecular formula for a polymer formed from three glucose molecules linked by dehydration reactions is C18H32O16.
Protein Structure and Bonds
- Proteins consist of 20 different amino acids, and their primary structure is linked by peptide bonds.
- Secondary structure includes α helix and β pleated sheets stabilized by hydrogen bonds.
- Tertiary structure represents the overall 3D shape of a protein, influenced by various interactions among R groups.
Lipids and Saturated Fats
- Lipids are hydrophobic and insoluble in water, contributing to cell membrane structures.
- Saturated fats are more common in animal products and solid at room temperature, containing no double bonds in their fatty acid chains.
Genetic Material and Nucleic Acids
- DNA and RNA consist of four nucleotides and serve distinct functions in genetic coding and expression.
- Cells incorporate radioactive labels into nucleic acids and proteins when grown in specific media, indicating the synthesis of these macromolecules.
Misfolding and Disease
- Misfolded polypeptides lead to diseases such as Alzheimer's and Parkinson's, underlining the importance of proper protein folding.
- A single amino acid change can significantly impact a protein's primary structure and potentially alter its biological function.
Interaction of Amino Acids
- The side chain of amino acids determines their position in a globular protein; hydrophilic amino acids tend to be on the exterior while hydrophobic ones are internal.
- Disulfide bonds play a crucial role in stabilizing the specific 3D shapes of folded polypeptides.
Summary of Structure Types
- Primary: Sequence of amino acids in a polypeptide.
- Secondary: α helices and β sheets formed by hydrogen bonding.
- Tertiary: Overall 3D structure influenced by interactions among R groups.
- Quaternary: Structure formed by multiple polypeptide subunits associating together.
Key Takeaways
- Enzymatic and chemical reactions are vital in macromolecule synthesis and metabolism.
- Understanding the structure and properties of biological macromolecules is essential for comprehending their functions in living organisms.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.