Bio Chapter 5
Starch and cellulose ________.
Are polymers of glucose
Sucrose is formed when glucose is joined to fructose by a(n) _____.
Glycosidic linkage
You would like to promote the smooth passage of food through your digestive tract. Which of the following should be your preferred food group?
Cellulose and fructose
Palm oil and coconut oil are more like animal fats than are other plant oils. Because they _____ than other plant oils, they may contribute to cardiovascular disease.
Contain fewer double bonds
Saturated fats ________.
Contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms
You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. What is the significance of this finding?
Cysteine residues are involved in disulfide bridges that help form tertiary structure.
The central rule of molecular biology states that ________.
DNA is transcribed into RNA, which is translated into protein
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart.
The building blocks or monomers of nucleic acid molecules are called _____.
Nucleotides
A hydrophobic amino acid R group (side group) would be found where in a protein?
On the inside of the folded chain, away from water
In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits ________.
Altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered
Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides?
Alzheimer's and Parkinson's
How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule?
19
In carbohydrates, the ratio of hydrogen (H) to oxygen (O) is ________.
2:1
If one strand of a DNA molecule has the sequence of bases 5-ATTGCA-3, the mRNA synthesized following the template will be ________.
3-UAACGU-5
Homo sapiens have 23 pairs of chromosomes. This implies that ________.
46 double-stranded DNA molecules are present in each somatic cell
Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA?
5´-ATGC-3´ with 5´-GCAT-3´
Which of the following is not a polymer?
Glucose
When nucleotides polymerize to form a nucleic acid _____.
A covalent bond forms between the sugar of one nucleotide and the phosphate of a second
For lipids to be fluid at room temperature, they should have ________.
A higher number of cis double bonds
Which of the following descriptions best fits the class of molecules known as nucleotides?
A nitrogenous base, a phosphate group, and a sugar
A glycosidic linkage is analogous to which of the following in proteins?
A peptide bond
Which molecule is a nucleotide?
ATP
Which functional group can act as a base?
Amino
Starch is composed of ________.
Branched amylopectin and unbranched amylose
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions?
C60H102O51
Which of the following categories includes all others in the list?
Carbohydrate
Which functional group can act as an acid?
Carboxyl
Which parts of the amino acids X and Y are involved in the formation of a peptide bond?
Carboxyl group of X and amino group of Y
Which polysaccharide is an important component in the structure of many animals and fungi?
Chitin
The flow of genetic information in a cell goes from _____.
DNA to RNA to protein
Cooking oil and gasoline (a hydrocarbon) have no affinity for water because they _____.
Do not have a polar or charged region
Humans can digest starch but not cellulose because ________.
Humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose
The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Hydrogenated vegetable oil ________.
Is solid at room temperature
A molecule with the chemical formula C6H12O6 is probably a _____.
Monosaccharide
The characteristic that all lipids have in common is that _____.
None of them dissolves in water
The relation between amino acid and polypeptide is similar to the relation between ________.
Nucleotide and nucleic acid
If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled?
RNA
Some regions of a polypeptide may coil or fold back on themselves. This is called _____, and the coils or folds are held in place by _____.
Secondary structure...hydrogen bonds
What structural difference accounts for the functional differences between starch and cellulose?
Starch and cellulose differ in the glycosidic linkages between their glucose monomers.
Which of the following statements about the 5 end of a polynucleotide strand of RNA is correct?
The 5 end has a phosphate group attached to the number 5 carbon of ribose.
What component of amino acid structure varies among different amino acids?
The components of the R group
Which feature of large biological molecules explains their great diversity?
The many ways that monomers of each class of biological molecule can be combined into polymers
In an RNA sample, ________.
The number of purine may or may not equal the number of and pyrimidine
People who are lactose intolerant cannot extract energy from milk because ________.
They are missing an enzyme
A tripeptide has ________.
Three amino acids, two peptide bonds
A dehydration reaction (or condensation reaction) is the process in which _____.
Water molecules are produced as a polymer is formed from monomers
Maltose is a disaccharide that can easily be digested into glucose molecules. The glycosidic linkage between glucose molecules in maltose is ________.
α 1-4
Plant cell walls consist mainly of _____.
Cellulose
What does the term insoluble fiber refer to on food packages?
Cellulose
Review Question 13, 14, 21, 22, 23, 24, 40, 41, 42, 45, 62, 64, 65, 85, 86, 90, 115
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A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism is more closely related to _____.
Frogs than to humans
One of the primary functions of RNA molecules is to _____.
Function in the synthesis of proteins
The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the α form. Which of the following could amylase break down?
Glycogen, starch, and amylopectin
Phospholipids and triglycerides both _____.
Have a glycerol backbone
Which of the following statements is true for lipids?
Lipids mix poorly with water.
What makes lipids/fats hydrophobic?
Presence of relatively nonpolar CH bonds
The structural level of a protein least affected by a disruption in hydrogen bonding is the
Primary level
You disrupt all hydrogen bonds in a protein. What level of structure will be preserved?
Primary structure
There are four levels of protein structure. These figures show primary, secondary, tertiary, and quaternary protein structure. Which level(s) of protein structure may be stabilized by covalent bonds?
Primary, tertiary and quaternary levels of protein structure
These figures show the four levels of protein structure: primary, secondary, tertiary, and quaternary structure. Which level of protein structure is characteristic of some, but not all, proteins?
Quaternary level of protein structure
Which of the following provides the information necessary to stipulate a protein's 3-D shape?
Sequence of amino acids in the polypeptide chain
Which of the following statements is true about proteins?
Some proteins form a complete 3-D structure only when they interact with their targets
What is the major structural difference between starch and glycogen?
The amount of branching that occurs in the molecule
Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?
The phosphodiester linkages of the polynucleotide backbone would be broken.
How do phospholipids interact with water molecules?
The polar heads interact with water; the nonpolar tails do not.
The difference between an aldose sugar and a ketose sugar is ________.
The position of the carbonyl group
Which of the following statements concerning unsaturated fats is true?
They have double bonds in the carbon chains of their fatty acids.
Which of the following is a major difference between RNA and DNA?
Type of sugar