week 3 mastering hw

polyssaccharide

A carbohydrate that yields many monosaccharides when hydrolyzed is a

e (Monomers are joined together in a reaction in which two molecules are covalently bonded to each other through the loss of a water molecule; this is called a condensation reaction or, specifically, a dehydration reaction.)

A dehydration reaction (or condensation reaction) is the process in which __________. a. None of the choices are correct. b. water molecules are used as a source of raw material to break down polymers to monomers c. water molecules are attracted to each other d. the bonds between the individual monomers of a polymer are broken by the addition of water molecules e. water molecules are produced as a polymer formed from monomers

a (Cholesterol is an important component of animal cell membranes.)

A function of cholesterol that does not harm health is its role _____. a. as a component of animal cell membranes b. All of cholesterol's effects cause the body harm. c. the most abundant male sex hormone d. in calcium and phosphate metabolism as the e. primary female sex hormone

d

A nucleotide is composed of a(n) _____. a. glycerol, a nitrogen-containing base, and a five-carbon sugar b. sulfhydryl group, a nitrogen-containing base, and a five-carbon sugar c. phosphate group, a nitrogen-containing base, and a hydrocarbon c. phosphate group, a nitrogen-containing base, and a five-carbon sugar d. amino group, a nitrogen-containing base, and a five-carbon sugar

carbohydrate

A simple sugar is composed of equal parts carbon and water, which gave rise to the general name of any sugar as a

structural

Arrow A is indicating __ protein

d (In the same way that the same letters can be arranged to make different words with different meanings, the same amino acids can be arranged in different linear sequences to form different proteins with different shapes and functions.)

As a researcher in a protein lab, you analyze two different proteins for their shape and the amino acids they contain. Your results show that the two proteins have exactly the same numbers and types of amino acids, but they have different shapes. What is the best explanation for these results? a. With only 20 amino acid types to work with, many proteins must have the same numbers and types. b. Proteins from the same functional class (enzymatic, structural, etc.) contain exactly the same amino acids. c. All proteins have the same numbers and types of amino acids. Differences between proteins are all based on shape. d. Each protein has a unique linear sequence of amino acids.

b (This formula only applies to simple sugars, which are equal parts carbon and water. Complex sugars, which do not have this general formula, are also carbohydrates.)

Carbohydrates, more commonly known as sugars, are made up of carbon, oxygen, and hydrogen atoms. The smallest unit of a carbohydrate is a monosaccharide. Two monosaccharides make up a disaccharide, and many monosaccharides make up a polysaccharide. Disaccharides and polysaccharides can be hydrolyzed back into the individual monosaccharide units. Select the statement that is incorrect. a. Complex sugars are carbohydrates. b. All carbohydrates have the general formula Cn(H2O)nCn(H2O)n c. Simple sugars are carbohydrates. d. Simple sugars contain only carbon, oxygen, and hydrogen atoms.

b (The immune system is involved in protecting the body against invasion by foreign objects.)

Defensive proteins are manufactured by the _____ system. a. integumentary b. immune c. digestive d. cardiovascular e. nervous

a (Water rejects nonpolar molecules such as fats, so fats travel inside particles that are coated with polar parts of phospholipids and proteins.)

Dr. Haxton told one of his students, "To move in the bloodstream, fats need the help of phospholipids." What would a good student say? a. Yes. Nonpolar molecules aren't compatible with water. b. Right. Fats are too polar to travel alone in water. c. Not so. Fats are small enough to travel easily without help. d. You have it backwards. Fats help phospholipids to travel. e. Sorry, Dr. Haxton! Help comes from cholesterol, not phospholipids.

a (100 nucleotide pairs are a total of 200 nucleotides. Because of base pairing, if there are 25 adenine there must also be 25 thymine. This leaves 200-50 = 150 nucleotides to be divided evenly between guanine and cytosine)

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain? a. 75 b.50 c. 200 d. 25 e. 150

c (Adenine pairs with thymine and guanine pairs with cytosine.)

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand? a. 3'-UAAACG-5' b. 3'-ATTTGC-5' c. 3'-TAAACG-5' d. 3'-GCAAAT-5' e. 3'-TUUUCG-5'

simple shape (Proteins are complex molecules made of many amino acid monomers. Depending on the focus and goal of the illustration, depictions can range from very detailed to very simple. Space-filling models show every atom, and wireframes show all side chains. Simplified diagrams and shapes use very general shapes to represent proteins.)

If you wanted to show a generalized protein in which the focus is on the protein's function rather than its structure, you should use a

wireframe model (Proteins are complex molecules made of many amino acid monomers. Depending on the focus and goal of the illustration, depictions can range from very detailed to very simple. Space-filling models show every atom, and wireframes show all side chains. Simplified diagrams and shapes use very general shapes to represent proteins.)

If you wanted to show the 3-dimensional shape of a protein by showing the amino acid side chains and their interactions, you should use a

space filling model (Proteins are complex molecules made of many amino acid monomers. Depending on the focus and goal of the illustration, depictions can range from very detailed to very simple. Space-filling models show every atom, and wireframes show all side chains. Simplified diagrams and shapes use very general shapes to represent proteins.)

If you wanted to show the 3-dimensional shape of a protein, including all of the atoms composing it, you should use a

ribbon model (Proteins are complex molecules made of many amino acid monomers. Depending on the focus and goal of the illustration, depictions can range from very detailed to very simple. Space-filling models show every atom, and wireframes show all side chains. Simplified diagrams and shapes use very general shapes to represent proteins.)

If you wanted to show the 3-dimensional shape of a protein, including the backbone structure, folds, and coils, you should use a

simplified diagram (Proteins are complex molecules made of many amino acid monomers. Depending on the focus and goal of the illustration, depictions can range from very detailed to very simple. Space-filling models show every atom, and wireframes show all side chains. Simplified diagrams and shapes use very general shapes to represent proteins.)

If you wanted to show the general shape of a protein, along with some important functional details such as folds and coils, you should use a

disaccharide

Lactose, the sugar in milk, is a __ because it can be split into two monosaccharides.

adenine-thymine (In a DNA sequence, the purine adenine always pairs with the pyrimidine thymine, and the purine guanine always pairs with the pyrimidine cytosine.)

Pair up the nucleotide bases with their complementary partners.

guanine-cytosine (In a DNA sequence, the purine adenine always pairs with the pyrimidine thymine, and the purine guanine always pairs with the pyrimidine cytosine.)

Pair up the nucleotide bases with their complementary partners.

b

Part complete Proteins are polymers of _____. a. nucleotides b. amino acids c. hydrocarbons d. CH2O units e. glycerol

b (Enzymatic proteins, or enzymes, are chemical agents that selectively speed up chemical reactions without being consumed by the reaction.)

Proteins perform a variety of functions in living organisms. The protein lysozyme (shown in the figure) is found in tears and saliva where it prevents infection by catalyzing the destruction of specific molecules on the surface of many kinds of bacteria. To which functional class of proteins does lysozyme belong? a. Structural protein b. Enzymatic protein c. Storage protein d. Transport protein e. Hormonal protein

b (Secondary structure is the localized folding and/or coiling of the primary structure of a polypeptide. It results from hydrogen bonding between atoms of the polypeptide backbone.)

Some regions of a polypeptide may coil or fold back on themselves. This folding is called __________, and the coils or folds are held in place by __________. a. secondary structure, peptide bonds b. secondary structure, hydrogen bonds c. tertiary structure, hydrogen bonds d. tertiary structure, covalent bonds e. primary structure, covalent bonds

Both DNA and RNA

Sort the parts of a nucleic acid according to whether each occurs exclusively in DNA, exclusively in RNA, or in both types of nucleic acid.

exclusively DNA

Sort the parts of a nucleic acid according to whether each occurs exclusively in DNA, exclusively in RNA, or in both types of nucleic acid.

exclusively RNA

Sort the parts of a nucleic acid according to whether each occurs exclusively in DNA, exclusively in RNA, or in both types of nucleic acid.

deoxyribose

Sort these nucleotide building blocks by their name or classification.

phosphate

Sort these nucleotide building blocks by their name or classification.

purine

Sort these nucleotide building blocks by their name or classification.

pyrimidine

Sort these nucleotide building blocks by their name or classification.

ribose

Sort these nucleotide building blocks by their name or classification.

e (Peptide bonds link together the amino acids of a protein's primary structure.)

Tertiary structure is NOT directly dependent on _____. a. ionic bonds b. hydrogen bonds c. hydrophobic interactions d. bonds between sulfur atoms e. peptide bonds

d (Almost all the covalent bonds in lipids are nonpolar, causing their solubility in water to be extremely low. Lipids are hydrophobic substances.)

The characteristic that all lipids have in common is __________. a. they do not have a high energy content b. they are all acidic when mixed with water c. they all contain nitrogen d. none of them dissolves in water e. they are all made of fatty acids and glycerol

d

The four main categories of large biological molecules present in living systems are __________. a. proteins, DNA, RNA, and steroids b. monosaccharides, lipids, polysaccharides, and proteins c. nucleic acids, carbohydrates, monosaccharides, and proteins d. RNA, DNA, proteins, and carbohydrates e. proteins, nucleic acids, carbohydrates, and lipids

e (Electronegative oxygen and nitrogen atoms leave hydrogen atoms with partial positive charges.)

The secondary structure of a protein results from _____. a. ionic bonds b. bonds between sulfur atoms c. hydrophobic interactions d. peptide bonds e. hydrogen bonds

d (The side chains in the section of the protein that is embedded in the membrane will be in contact with the fatty acid core of the membrane, which is hydrophobic.)

The simplified diagram of rhodopsin shows the protein embedded in the phospholipid bilayer of the membrane. Portions of the protein extend into the intracellular and extracellular spaces. Which characteristics best describe the side chains in the part of the protein in contact with the phospholipid tails of the membrane? a. Polar; hydrophilic. b. Charged - basic; hydrophilic c. Charged - acidic; hydrophilic d. Non-polar; hydrophobic

c (Nitrogenous base pairs are joined by hydrogen bonds.)

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases. a. S—S bonds b. hydrophilic interactions c. hydrogen bonds d. covalent bonds e. ionic bonds

c (The primary structure of a protein is the specific linear sequence of amino acids forming the protein. The amino acids are joined by covalent peptide bonds. Tertiary structure, producing the unique structure of a protein, is stabilized by interactions among the R groups on each amino acid in the protein. Tertiary structure may be stabilized by covalent bonds, called disulfide bridges, that form between the sulfhydryl groups (SH) of two cysteine monomers. Tertiary structure may also be stabilized by weaker interactions, including hydrogen bonds between polar and/or charged areas, ionic bonds between charged R groups, and hydrophobic interactions and van der Waals interactions among hydrophobic R groups. Many globular proteins are made up of several polypeptide chains called subunits stuck to each other by a variety of attractive forces but rarely by covalent bonds. Protein chemists describe this as quaternary 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? a. None of the levels of protein structure is stabilized by covalent bonds. b. Secondary level of protein structure c. Primary, tertiary and quaternary levels of protein structure

c (Quaternary structure results from the aggregation of two or more polypeptide subunits, and not all proteins are composed of more than one polypeptide.)

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? a. Tertiary level of protein structure b. Secondary level of protein structure c. Quaternary level of protein structure

true (enzymes in the digestive tract break down food molecules, which is a process that occurs by hydrolysis.)

True or false? Enzymes in the digestive tract catalyze hydrolysis reactions.

true

True or false? Peptidoglycan is a polysaccharide found only in bacteria.

b

What do fats, steroids, and waxes have in common? (a) Moderate polarity. (b) Low solubility in water. (c) They occur in membranes. Both (a) and (c). Both (b) and (c).

b,c (The phosphate attaches to the glycerol and provides a place for another small molecule to attach to the phospholipid. The phosphate has a charge, so it interacts with polar water molecules)

What functional feature(s) does the phosphate group contribute to the structure of a phospholipid? a. place to attach fatty acids. b. place to attach another small charged molecule. c. negative charge to interact with water d. place where bonds can form between adjoining phospholipids e. nonpolar group that avoids water

d (The hydrophobic tails interact with each other and are repelled by water, while the heads are hydrophilic and are attracted to water. This dual nature causes groups of phospholipids to assemble into distinct layers to minimize tail contact with water and maximize head contact with water.)

What holds phospholipids together in a bilayer formation? a. ionic interactions between phospholipid tails b. covalent bonds between polar heads c. interaction of cis-double bonds in tails with polar heads d. hydrophilic and hydrophobic interactions with water

a (Both starch and cellulose are glucose polymers, but the glycosidic linkages in these two polymers differ. Glucose can have two slightly different ring structures. When glucose forms a ring, the hydroxyl group attached to the number 1 carbon is positioned either below (alpha) or above (beta) the plane of the ring. In starch, all the glucose monomers are in the alpha configuration. In cellulose, all the glucose monomers are in the beta configuration. As a result, every other glucose monomer is "upside down" with respect to its neighbors. The differing glycosidic linkages in starch and cellulose give the two molecules distinct three-dimensional shapes, leading to key functional differences.)

What structural difference accounts for the functional differences between starch and cellulose? a. Starch and cellulose differ in the glycosidic linkages between their glucose monomers. b. Starch is a polymer of glucose, whereas cellulose is a polymer of fructose. c. Starch can be digested by animal enzymes, whereas cellulose cannot.

c (The amino acids of a protein are linked by peptide bonds.)

What type of bond joins the monomers in a protein's primary structure? a. S - S b. hydrogen c. peptide d. hydrophobic e. ionic

dehydration and peptide (Proteins are complex molecules made of many repeating amino acid monomers linked together by covalent peptide bonds. Recognizing amino acids and understanding how they are linked together into polypeptides provides a foundation for understanding the three-dimensional architecture of proteins.)

When two amino acid monomers are positioned so that the carboxyl group of one is adjacent to the amino group of the other, they can be joined through a __ reaction. This reaction from a(n) ___ bond

a (Amylose is formed from a-1,4-glycosidic linkages of glucose.)

Which complex carbohydrate contains only a-1,4-glycosidic linkages? a. Amylose b. Amylopectin c. Cellulose d. Glycogen

b (Biological molecules belong to four main classes, and are constructed from only 40 to 50 common monomers (and a few rare ones) made of only a few of the 92 naturally occurring elements. The diversity of biological molecules is due to differences in the arrangements of the monomers in each molecule.)

Which feature of large biological molecules explains their great diversity? a. The diversity of elements found in large biological molecules b. The many ways that monomers of each class of biological molecule can be combined into polymers c. The many classes of large biological molecules

c (The replacement of one of the fatty acids with a polar chemical group makes phospholipids more soluble in water than fats.)

Which molecule is less soluble in water--a fat or a phospholipid? Why? a. A phospholipid is less soluble in water because it is smaller than a fat molecule. b. A fat molecule is less soluble in water because it has more carbons and hydrogens than a phospholipid. c. A fat molecule is less soluble in water because it has three non-polar fatty acids and no polar or charged head like a phospholipid has. d. A phospholipid is less soluble in water because even though it has one end that is hydrophilic, the end that is hydrophobic is larger

b (A lipid is a hydrophobic polymer, not a carbohydrate)

Which molecule is not a carbohydrate? a.Glycogen b. Lipid c. Starch d. Cellulose

a (Nucleotide monomers make up nucleic acids.)

Which monomers make up RNA? a. Nucleotides b. Amino acids c. Polymers d. Simple sugars

a (Cellulose is indeed the main structural component of plant cells walls.)

Which of the following complex carbohydrates is listed with its correct function? a. Cellulose: structural component of plant cell walls b. Chitin: constituent of bacterial cell walls c. Starch: primary energy-storage molecule in animals d. Amylose: main component of plant starch

a (The central carbon atom in an amino acid is bonded to an amino functional group, a carboxyl functional group, a side chain, and hydrogen.)

Which of the following is not attached to the central carbon atom in an amino acid? a. An oxygen b. A side chain ("R group") c. A carboxyl functional group d. An amino functional group

c

Which of the following statements about monosaccharide structure is true? a. Aldoses and ketoses differ in the position of their hydroxyl groups. b. A six-carbon sugar is called a pentose. c. Monosaccharides can be classified according to the spatial arrangement of their atoms. d. All monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms.

c (A hydroxyl group is removed from the carboxyl group of one amino acid and hydrogen is removed from the amino group of the other amino acid, allowing a bond to form between the two groups.)

Which of the following statements about the formation of polypeptides from amino acids is true? a. A bond can form between any carbon and nitrogen atom in the two amino acids being joined. b. Polypeptides form by condensation or hydrolysis reactions. c. A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. d. The reaction occurs through the addition of a water molecule to the amino acids.

a (Ovalbumin is a storage protein.)

Which of these does NOT contain a structural protein? a. ovalbumin b. tendons c. ligaments d. muscles e. spider silk

d (Alpha helices and beta pleated sheets are characteristic of a protein's secondary structure.)

Which of these illustrates the secondary structure of a protein?

d (Biological membranes are made of phospholipids that have assembled with the polar heads facing out to interact with the water, and the non-polar tails pushed together in the interior of the membrane.)

Which of these images shows the correct orientation of phospholipids in a biological membrane?

d (RNA is a nucleic acid)

Which of these is NOT a lipid? a. phospholipid b. wax c. steroids d. RNA e. cholesterol

the last one (Phospholipids are composed of a phosphate group, a glycerol, and fatty acids.)

Which of these is a phospholipid?

b (Olive oil is a plant oil, and most plant oils are rich in unsaturated fats.)

Which of these is rich in unsaturated fats? a. beef fat b. olive oil c. butter d. a fat that is solid at room temperature e. lard

b (The carboxyl group (COOH) contains two oxygen atoms that tend to pull electrons away from the hydrogen atom, so this group tends to lose a proton and is acidic.)

Which part of an amino acid is always acidic? a. Side chain ("R group") b. Carboxyl functional group c. Amino functional group d. None of the above

c (Proteins are composed of amino acids joined together.)

Which polymers are composed of amino acids? a. Monomers b. Carbohydrates c. Proteins d. Nucleic acids

b (The N-acetylglucosamine and N-acetylmuramic acid units that make up peptidoglycan are composed of modified glucose monomers.)

Which polysaccharide contains a modified monosaccharide? a. Cellulose b. Peptidoglycan c. Starch d. Glycogen

3'-GCTATAACTCGATTCGAA-5'

Write the complementary sequence for the following DNA sequence, in order from 3' to 5': 5′−CGATATTGAGCTAAGCTT−3′

monosaccaride

a __ cannot be hydrolyzed any further

receptor (This protein has a binding site for a signal protein and can emit a second messenger.)

arrow D is indicating ___ protein

Monosaccharides

carbohydrates monomers or components

Polysaccharides

carbohydrates polymer or larger molecule

glycosidic linkages

carbohydrates type of linkage

b (DNA and RNA have similar structures: a pentose sugar with a nitrogenous base and a phosphate group. DNA and RNA differ in the type of pentose sugar each possesses (DNA has deoxyribose; RNA has ribose) and in one base (DNA has thymine; RNA has uracil).)

dentify three possible components of a DNA nucleotide. a. adenine, phosphate group, ribose b. deoxyribose, phosphate group, thymine c. guanine, phosphate group, ribose cytosine, phosphate group, ribose d. deoxyribose, phosphate group, uracil e. cytidine, phosphate group, ribose

acidic-glutamic acid neutral polar-threonine, tyrosine neutral nonpolar-valine, tryptophan

drag each to the appropriate ben

basic-arginine neutral polar-glutamine, asparagine neutral non polar alanine

drag each to the appropriate ben

basic-lysine neutral polar-serine neutral non polar-proline, methionine, phenylalanine

drag each to the appropriate ben

fatty acids

fats monomers or components

triaclyglcerols

fats polymer or larger molecule

ester linkages

fats type of linkage

2 (Two fatty acids are attached to the glycerol and make up the tails of the phospholipid.)

how many fatty acids are in a phospholipid?

DNA is used for storage of genetic information. The presence of deoxyribose as the sugar in DNA makes the molecule more stable and less susceptible to hydrolysis. The 2'-oxygen on the ribose found in RNA makes RNA much more susceptible to breakdown. It is important that mRNA be easily broken down, to ensure that the correct levels of protein are maintained in the cell.

how to determine DNA vs RNA

All of the genetic material in all living organisms is made from these basic building blocks of nucleotides

how to determine classification

labeling

labeling

The base pair adenine-cytosine occurs very rarely in nature. It only happens during a mutation event. When the DNA is replicated, one of the two daughters will contain a guanine-cytosine base pair in the location of the mutation, and the other daughter will contain an adenine-thymine base pair.

most stable to least stable

nucleotides

nucleic acids monomers or components

polynucleotides

nucleic acids polymer or larger molecule

phosphodiester linkages

nucleic acids type of linkage

amino acids

proteins monomers or components

polypeptides

proteins polymer or larger molecule

peptide bonds

proteins type of linkage

saturated fat (The fatty acid tails lack double bonds.)

this figure is an example of a a. nucleic acid b. saturated fat c. protein d. unsaturated fat e. steroid

dehydration (Condensation, also called dehydration, refers to the removal of a water molecule during the linking of monomers.)

what is another name for a condensation reaction?

hydrolysis (Hydrolysis is the opposite of a condensation reaction. During hydrolysis, a water molecule is used up in the breaking of a bond between two monomers. An H is added to one monomer, and an OH is added to the other.)

what is the name of the process during which bond between two monomers is broken?

simple sugar

what monomers are Carbohydrate polymers are made up of

nucleotide

what monomers are Nucleic acid polymers are made up of

amino acid

what monomers are Protein polymers are made up of

a (A nucleotide consists of three parts: a nitrogenous base, a pentose sugar, and one or more phosphate groups. ATP consists of a nitrogenous base (adenine), a pentose sugar, and three phosphate groups.)

which molecule is a nucleotide? a. ATP b. Deoxyribose c. The amino acid glycine