Chapter 3 Flashcards
special case amino acids
Cysteine; Cys, C
Glycine; Gly, G
Proline; Pro, P
hydrophilic, uncharged amino acids
Serine; Ser, S
Threonine; Thr, T
Asparagine; Asn, N
Glutamine; Gln, Q
Tyrosine; Tyr, Y
electrically charged, hydrophilic amino acids
Arginine; Arg, R
Histidine; His, H
Lysine; Lys, K
Aspartic acid; Asp, D
Glutamic acid; Glue, E
nonpolar, hydrophobic amino acid
Alanine; Ala, A
Isoleucine; Ile, I
Leucine; Leu, L
Methionine; Met, M
Phenylalanine; Pha, F
Tryptophan; Trp, W
Valine; Val, V
linkages that form lipids
ester linkages
(are used to form these)
2-layered structure
bilayer
monomer
small molecule that can be combined with other similar molecules to form oligomers or polymers
R group
(synonym)
side chain
(synonym)
R group
distinguishing atoms of a particular amino acid
glycerol
(structure)
glycerol
3-Carbon alcohol with 3-OH groups
component of phospholipids and triglycerides
saturated fatty acid
fatty acid only containing single bonds within hydrocarbon chain
monosaccharide
monomer of carbohydrates
-a simple sugar
beta-pleated sheet
bonding between amino and carboxyl side groups resulting in _____
beta-pleated sheet
protein secondary structure resulting from regions of polypeptide running antiparallel to each other
quaternary structure
specific 3D arrangement of protein subunits
(e.g. full hemoglobin molecule consists of 4 subunits)
triglyceride
lipid containing a glycerol and 3 fatty acids
hexose
sugar containing 6 carbon atoms
glycosidic linkage
bonds between carbohydrates through an O atom
glycosidic linkage
linkage between carbohydrate molecules
optical isomers
mirror-image isomers
heat shock protein
chaperone protein expressed in cells exposed to environmental stressors (e.g. high/low temps)
carbohydrates
C, H, and O-containing compounds (in the ratio of 1:2:1)
carbohydrate examples (3)
sugars
starch
cellulose
chaperone
protein that guard other proteins by counteracting molecular interactions that threaten their 3D structure
disaccharide
carbohydrate consisting of two monosaccharides
-a simple sugar
bilayer
2-layered structure
condensation rxn
rxn in which two molecules are covalently joined with the release of a water molecule
fatty acid
molecule consisting of long nonpolar hydrocarbon chain(s) and a polar carboxyl group
found in many lipids
structural isomers
molecules consisting of the same types/numbers of atoms; atoms are bonded differently in each molecule
protein
long chain polymer consisting of amino acids; usually coiled into a compact molecule
secondary structure
localized protein folding, including alpha helices and beta (pleated) sheets
polysaccharide
(2 examples)
macromolecule consisting of many monosaccharides
cellulose
starch
primary structure
sequence of amino acids in a protein
phospholipid
lipid containing phosphate group
important constituent of cellular membranes
polymer
large molecule consisting of similar or identical subunits
unsaturated fatty acid
fatty acid containing 1+ double bonds within hydrocarbon chain
tertiary structure
relative location of atoms/molecules within the 3D shape of a protein
OR relative shape of a protein
glucose
most common monosaccharide
isomers
molecules consisting of same types/numbers of atoms, but differences exist in bonding patterns
lipid
(and 5 examples)
nonpolar, hydrophobic molecules
- fats
- oils
- waxes
- steroids
- phospholipids
fat
triglyceride that is solid at room temp
macromolecule
large polymeric molecule
MW > 1,000
disulfide bridge
covalent bond between two sulfur atoms
links two molecules or remote parts of same molecule
pentose
sugar containing 5 carbon atoms
amphipathic
molecule having both hydrophobic and hydrophilic regions
hydrolysis reaction
chemical reaction that breaks a bond by inserting components of water
oligosaccharide
polymer containing small number of monosaccharides
peptide linkage
bond between amino acids in protein
bond between carboxyl group and amino group w/ loss of a water molecule
peptide linkage
(details)
alpha helix
part of a protein’s secondary structure; right handed spiral
bonds are between the H in the amino group and the O in the carboxyl group
alpha helix
hydrogen bonds between the H in the amino group and the O in the carboxyl group form a(n) _____
phospholipid bilayer
composes biological membranes
consists of 2 layers of amphipathic lipids; hydrophilic heads on outside of membrane, and hydrophobic tails on inside of membrane
side chain
distinguishing “R” group of an amino acid
functional group
characteristic combination of atoms/bonds that contribute to specific properties of a molecule
denaturation
loss of enzyme or nucleic acid molecular activity as a result of structural changes induced by environmental conditions
ester linkage
condensation reaction between carboxyl group of a fatty acid and a hydroxyl group of an alcohol
If 27 monomers of this general type (shown) were linked in a single-stranded chain, how many bonds would be formed, and what is the bond type called?
A. 27, peptide bond
B. 26, glycosidic linkage
C. 27, glycosidic linkage
D. 26, ester linkage
E. 28, peptide bond
B
oil
triglyceride; liquid at room temp
This figure shows the testosterone molecule. Which of the following statements regarding these non-glycerol based lipids is false?
A. Non-glycerol based lipids are water soluble.
B. Carotenoids are light absorbing pigments.
C. Steroids are derived from cholesterol.
D. The vitamins A, D, E, and K are lipid soluble.
E. Waxes are formed by ester linkages between long chain fatty acids and long chain alcohols.
A
Which of the five labeled bonds will be broken when this molecule undergoes hydrolysis?
A. 1
B. 2
C. 3
D. 4
E. 5
C
This figure shows the relative amounts of substances found in living tissues. Which of the following statements about these substances is false?
A. The chemical behavior of molecules is determined by their functional groups.
B. Isomers are molecules with the same number and type of atoms arranged in different ways.
C. Hydrogen bonds are what hold monomeric substances in their polymeric form.
D. Water is required to break apart a polymer via hydrolysis.
E. Condensation refers to the formation of water as covalent bonds are formed between monomers (i.e., a polymer is formed).
C
Which of the following statements about proteins is false? You may wish to refer to the generalized amino acid shown.
A. The sequence of amino acids is the primary structure of the protein.
B. Amino acids are isomers that are usually present in the D form in living cells.
C. A peptide linkage is a covalent bond that joins amino acids together.
D. The peptide backbone consists of the repeating sequence —N—C—C—.
E. The total number of different polypeptides containing seven amino acids is equal to 207.
B
Which of the following statements about the protein structure shown is false?
A. It is an example of secondary protein structure.
B. This structure can involve more than one polypeptide.
C. It can be present in a polypeptide that also contains an α-helical structure.
D. It is maintained by hydrogen bonding between amino acid side chains.
E. The presence of this structure is determined by the protein’s primary structure.
D
Which of the following statements about the protein shown here is false?
A. This protein has a primary structure.
B. This protein has a secondary structure.
C. This protein has a tertiary structure.
D. This protein has a quaternary structure.
E. Heating this protein would cause it to lose its secondary and tertiary structures.
D
Which statement about the two monosaccharides shown here is false?
A. These monosaccharides are isomers of a simple sugar with the formula C6H12O6.
B. These monosaccharides can form a disaccharide by a condensation reaction.
C. These monosaccharides could be joined together with a glycosidic linkage.
D. A β-glycosidic linkage will be formed between these monosaccharides.
E. In a disaccharide, these two monosaccharides could be joined at carbons 1 and 4.
D
Which of the following statements about starch (shown) is false?
A. The subunits in starch are all glucose.
B. Starch is insoluble since it cannot bind to water.
C. Branching limits the hydrogen bonding that can occur between different starch molecules.
D. The degree of branching varies in different types of starch.
E. Starch is more similar to glycogen than it is to cellulose.
B
Which of the following statements about the molecules shown is false?
A. They are all chemically modified carbohydrates.
B. Molecule 1 is a sugar phosphate.
C. Molecules 2 and 3 are amino sugars.
D. Chemically modified carbohydrates can be linked together.
E. They all are pentoses.
E
In the formation of a triglyceride from the components shown (1 and 2), _______ molecule(s) of compound 1 combine(s) with _______ molecule(s) of compound 2 to form a triglyceride plus _______ molecule(s) of water.
A. 1; 1; 1
B. 1; 3; 1
C. 1; 3; 3
D. 3; 3; 3
E. 3; 1; 3
C
Consider the two fatty acids shown (1 and 2). Which of the following statements regarding these fatty acids is false?
A. Fatty acid 1 contains a total of 16 carbons and 0 carbon–carbon double bonds.
B. Fatty acid 1 would be considered saturated.
C. Fatty acid 2 contains a carbon–carbon double bond.
D. Fatty acid 2 would be considered unsaturated.
E. Fatty acid 1 has a lower melting point than Fatty acid 2.
E
Large molecules that contain carbon and are held together by covalent bonds are categorized as
A. proteins
B. polymers
C. nucleic acids
D. macromolecules
E. monomers
D
Consider the two labeled regions (1 and 2) of the phospholipid (phosphatidylcholine) shown here. Select the choice below that makes the following statement true: Region 1 is _______ and would form the _______ of a cell membrane; region 2 is _______ and would form the _______ of a cell membrane.
A. hydrophobic; interior; hydrophilic; surface
B. hydrophobic; surface; hydrophilic; interior
C. hydrophilic; surface; hydrophobic; surface
D. hydrophilic; surface; hydrophobic; interior
E. hydrophilic; interior; hydrophobic; interior
D
The bonds that form between the monomers of polymeric macromolecules are ___ bonds.
A. hydrogen
B. peptide
C. disulfide
D. covalent
E. ionic
D
Quatenary structure of proteins refers to
A. the number and kind of polypeptide subunits the protein has.
B. the four-fold symmetry of the protein.
C. the arrangement of the protein’s atoms in 3D space.
D. the lipids or carbohydrates taht are attached to the proteins.
E. whether the chain is an α helix or a β helix.
A
The side chain of leucine is a hydrocarbon. In a folded protein, where would you expect to find leucine?
A. in the interior of a cytoplasmic enzyme
B. on the exterior of a protein embedded in a membrane
C. on the exterior of a cytoplasmic enzyme
D. both a and b
E. both a and c
D
Which of the following functional groups is the most polar?
A. hydroxyl
B. aldehyde
C. keto
D. carboxylic acids
E. sulfhydryl
A
Aspartate and glutamate are highly soluble in water; therefore, they
A. are hydrophobic.
B. have sulfur atoms in their side chains.
C. have electrically charged side chains.
D. are nonpolar.
E. form only left-hand isomers.
C
During the formation of a peptide linkage, a(n) ___ is formed.
A. molecule of water
B. disulfide bridge
C. hydrophobic bond
D. hydrophilic bond
E. ionic bond
A
Amino acids can be classified by the
A. number of monosaccharides they contain.
B. number of carbon-carbon double bonds in their fatty acids.
C. number of peptide bonds they can form.
D. number of disulfide bridges they can form.
E. characteristics of their side chains, or “R” groups.
E
Which of the following does not represent a correct monomer/polymer pairing?
A. monosaccharide/polysaccharide
B. amino acid/protein
C. triglyceride/cellulose
D. nucleotide/nucleic acid
E. monosaccharide/oligosaccharide
C
The atoms that make up carbohydrates are
A. C, H, and N.
B. C and H.
C. C, H, and P.
D. C, H, and O.
E. C, H, O, and N.
D
A fat contains fatty acids and
A. glycerol.
B. a base.
C. an amino acid.
D. a phosphate.
E. none of the above
A
Which of the following statements about the protein shown here is false?
A. This protein has a primary structure.
B. This protein has a secondary structure.
C. This protein has a tertiary structure.
D. This protein has a quaternary structure.
E. Heating this protein would cause it to lose its secondary and tertiary structures.
D
Cholesterol is soluble in cholorform, an organic solvent, but it is not soluble in water. Based on this information, what class of biological macromolecules does cholesterol belong to?
A. oligosaccharides
B. enzymes
C. proteins
D. carbohydrates
E. lipids
E
Oils and fats
A. are phosopholipids.
B. all contain the same fatty acids.
C. are triglycerides.
D. are polar hydrocarbons.
E. have peptide bonds.
C
Which of the following statements about condensation reactions is not true?
A. Protein synthesis results from them.
B. Polysaccharide synthesis results from them.
C. They involve covalent bonds.
D. They consume water as a reactant.
E. Different condensation reactions produce different kinds of macromolecules.
D
The most abundant molecule in the cell is
A. a carbohydrate.
B. a lipid.
C. a nucleic acid.
D. a protein.
E. water.
E
All proteins
A. are enzymes.
B. consist of one or more polypeptide chains.
C. are amino acids.
D. have quaternary structures.
E. are more soluble in nonpolar solvents than in water.
B
Which of the following statements about the primary structure of a protein is not true?
A. It may be branched.
B. It is held together by covalent bonds.
C. It is unique to that protein.
D. It determines the tertiary structure of the protein.
E. It is the sequence of amino acids in the protein.
A
The amino acid leucine
A. is found in all proteins.
B. cannot form peptide linkages.
C. has a hydrophobic side chain.
D. has a hydrophilic side chain.
E. is identical to the amino acid lysine.
C
All carbohydrates
A. are polymers.
B. are simple sugars.
C. consist of one or more simple sugars.
D. are found in biological membranes.
E. are more soluble in nonpolar solvents than in water.
C
Which of the following is not a carbohydrate?
a. Glucose
b. Starch
c. Cellulose
d. Hemoglobin
e. Deoxyribose
D
All lipids are
A. triglycerides.
B. polar.
C. hydrophilic.
D. polymers of fatty acids.
E. more soluble in nonpolar solvents than in water.
E
The amphipathic nature of phospholipids is
A. determined by the fatty acid composition.
B. important in membrane structure.
C. polar but not nonpolar.
D. shown only if the lipid is in a nonpolar solvent.
E. important in energy storage by lipids.
B
The quaternary structure of a protein
A. consists of four subunits—hence the name quaternary.
B. is unrelated to the function of the protein.
C. may be either alpha or beta.
D. depends on covalent bonding among the subunits.
E. depends on the primary structures of the subunits.
E
3-Carbon alcohol with 3-OH groups
component of phospholipids and triglycerides
glycerol
alanine
hydrophobic
valine
hydrophobic
phenylalanine
hydrophobic
leucine
hydrophobic
isoleucine
hydrophobic
arginine
hydrophilic
positive
proline
special case
glycine
special case
cysteine
special case
aspartic acid
(structure)
glutamic acid
(structure)
serine
(structure)
threonine
(structure)
asparagine
(structure)
glutamine
(structure)
tyrosine
(structure)
cysteine
(structure)
glycine
(structure)
proline
(structure)
alanine
(structure)
isoleucine
(structure)
leucine
(structure)
methionine
(structure)
phenylalanine
(structure)
tryptophan
(structure)
lysine
(structure)
valine
(structure)
histidine
(structure)
arginine
(structure)
valine
(structure)
tryptophan
(structure)
arginine
(structure)
histidine
(structure)
lysine
(structure)
aspartic acid
(structure)
glutamic acid
(structure)
serine
(structure)
threonine
(structure)
asparagine
(structure)
glutamine
(structure)
tyrosine
(structure)
cysteine
(structure)
glycine
(structure)
proline
(structure)
alanine
(structure)
isoleucine
(structure)
leucine
(structure)
methionine
(structure)
phenylalanine
(structure)
bonding between amino and carboxyl side groups resulting in _____
beta-pleated sheet
bonds between carbohydrates through an O atom
glycosidic linkage
hydroxyl
keto
aldehyde
phosphate
carboxyl
amino
hydrogen bonds between the H in the amino group and the O in the carboxyl group form a(n) _____
alpha helix
sulfhydryl
hydroxyl
keto
aldehyde
phosphate
carboxyl
amino
sulfhydryl
