final prep Flashcards
Which of the following monosaccharides is an aldose? Dihydroxyacetone Glyceraldehyde Glucose Lactose
Both B and C
When two monosaccharides are epimers:
They differ only in the configuration about one carbon atom
One is a furanose, the other a pyranose
One is an aldose, the other a ketose
They can form ring structures
They form O-glycosidic bonds
They differ only in the configuration about one carbon atom
Which pair is anomeric? A) D-ribose and D-galactose B) α-D-allose and β-D-allose C) D-Ribose and L-fructose D) D-glucose and L-glucose E) α-D-idose and β-L-idose
B
When forming the disaccharide maltose from two glucose monosaccharides:
Gas is eliminated
A condensation reaction occurs
An anomeric carbon is formed on carbon-1
An epimer is formed
A polysaccharide is formed
A condensation reaction occurs
Amylose and amylopectin are both polymers of:
A) α-D-glucose B) β-D-glucose C) Galactose D) Idose E) Maltose
A
Which statement about starch and glycogen is false?
A) Both have β-D-glucose monomers
B) Both starch and glycogen are energy storage polysaccharides
C) Both are homopolymers of glucose
D) Glycogen is more extensively branched than starch
E) Both have O-glycosidic linkages
A
Which monosaccharide is not a six-carbon monosaccharide? Idose Gulose Galactose Dihydroxyacetone Allose
Dihydroxyacetone
Which statement about cellulose is true?
Cellulose is found in plants
Cellulose is the primary storage polysaccharide of animal cells
Cellulose is found in DNA
The glucose residues of cellulose contain the same configuration as the glucose residues of amylose
Cellulose is an epimer of chitin
A
The polysaccharide chitin is most chemically similar to: Cellulose Dextrose Glycogen Starch Amylose
Cellulose
Which of the following is the most common monosaccharide on earth? Ribose Cellulose Chitin Sucrose Glucose
Glucose
The “D” in the D-carbohydrates stands for: 3-dimensional Dextrorotatory Derivative Design Double
Dextrorotory
Which compound does not fit the formal definition of a carbohydrate?
A. C6H12O6
B. C9H18O9
C. C3H6O3
D. C8H14O8
E. C5H10O5
D
Table sugar is also known as: Sucrose Dextrose Glucose Galactose Glycogen
Sucrose
Amylose has α1 → 6 branching about every \_\_\_\_\_\_\_\_ residues. 1 to 10 8 to 12 10 to 30 24 to 30 No branching
No branching
Besides C, H, and O, chitin has which other element in its structure?
F Cl P S N
N
Some carbohydrates form a(n)___________ structure, which resembles a structure in proteins.
A) α form
B) β-turn
C) βeta-sheet
D) D-configuration
E) α-helix
E
The equilibrium between _________ structures is called mutarotation.
A) Anomer and epimer
B) α and β
C) L and D
D) Helix and beta sheet
E) None of the above
B
Carbohydrates are not used in the following function.
Structure Energy storage RNA sugar Metabolic intermediate All of the above are functions.
All are functions
Which word is Greek for sugar?
Sugar Carbohydrate Saccharide Sucrose Starch
Saccharide
Table sugar dissolves easily in water. Given its structure, explain why this is.
Sucrose contains -OH groups which can form hydrogen bonds with water. These non-covalent interactions permit solubility by permitting carbohydrates to interact with water and become an aqueous solution.
A hiker is lost in the wilderness and without food. He runs across several beetles with hard chitin exoskeletons. Would he get nutrition in the form of glucose from eating these beetles? Explain.
The human enzyme cannot break down the bond between the glucose residues in chitin. The bond is a β1 →4, but human enzymes only act upon α 1 →4. So, no he should not eat the beetles as food.
How are oligosaccharides and polysaccharides similar in their structure? How are they different?
An oligosaccharide is a polymer of 2 to 20 monosaccharides joined together. A polysaccharide is more than 20 monosaccharides joined together. They are typically linked together by the same
1 → 4 linkages practically, and there are usually thousands of monosaccharides in a polysaccharide. In addition, polysaccharides can have branches in the structure, which permits them to form large complexes. In contrast, most oligosaccharides do not have branching.
Glycerol contains how many alcohol functional groups?
1
2
3
4
3
Which of the following are derived from or made from fatty acids? Cholesterol Carotenoids Phosphoglycerides Both A and B Both A and C
Phosphoglycerides
Triacylglycerols are made from a \_\_\_\_\_\_\_\_ and \_\_\_\_\_\_\_\_. glycerol; cholesterol glycerol; three fatty acids ceramide; three fatty acids ceramide; three cholesterols carotenoid; two cholesterols
glycerol and 3 fatty acids
Which of the following refers to carboxylic acids that are structural components of lipids?
Amino acids Anomers Fatty acids Gluconic acid Sphingolipids
FAtty acids
A particular lipid is a solid at room temperature, so it is called a(n) \_\_\_\_\_\_\_\_. Carotenoid Oil Sphingolipid Fat Membrane
fat
\_\_\_\_\_\_\_\_ are a class of membrane proteins that are firmly associated with the membrane bilayer. Peripheral protein Integral protein Channel protein Transport protein Inner transmembrane protein
Integral
Isoprene units are used to make \_\_\_\_\_\_\_\_\_\_\_\_\_. A. Fatty acids B. Carotenoid molecules C. Sphingolipids D. Both B and C E. All of the above
carotenoid molecules
Which notation is for a fatty acid with one double bond?
A) 18:1(Δ12)
B) 1:18(Δ12,15)
C) 1:12(Δ12)
D) 2:18(Δ12,15)
E) 12:1(Δ7,9)
A
Which notation indicates a 20-carbon omega-3 fatty acid that contains no other double bonds?
A) 20:1 (Δ11)
B) 20:1(Δ18)
C) 20:1(Δ17)
D) 20:1(Δ3)
E) 20:3(Δ3omega)
C
Which of the following is used as the backbone molecule in the formation of storage fats? Glycogen Glycerol Sphingolipid Glucose Phosphoglycerol
Glycerol
Which types of membrane lipids determine the blood type of humans? Triacylglycerols Phosphoglycerides Cholesterol Fatty acids Sphingolipids
Sphingolipids
Sphingolipids are found in high concentrations in the membranes of \_\_\_\_\_\_\_\_\_\_. organelles myelin sheaths all cells heart cells Vitamin K lipids
myelin sheaths
In a sphingolipid, the fatty acids are attached at carbon-2 by this type of linkage? Amide linkage An ether linkage An alcohol linkage A peptide linkage Alkyl linkage
Amide
Membrane proteins: Are sometimes peripheral Are sometimes integral Assist in the transport of molecules Can get nutrients in and the waste molecule out of the cell All are correct
all are correct
Peripheral membrane proteins
Go all the way through the membrane and are firmly attached to the membrane
Are firmly attached to the membrane
Are lipids that can be either on the top of the cell or bottom of the cell
Are associated with the inside or outside surface of the membrane
None of the above
are associated with the inside or outside surface of the membrane
Which statement best describes a general feature of membranes?
Individual lipid molecules are free to move in the membrane
The interior of the lipid bilayer is very polar
The membrane breaks easily
The polar heads face inward
The membrane is rigid
Individual lipid molecules are free to move in the membrane
Vitamin K is important for \_\_\_\_\_\_\_\_\_. Blood coagulation Blood type Myelin sheaths Membrane dynamics Dye formation
Blood coagulation
What molecule is not found in membrane bilayers? Phosphoglycerides Sphingolipid Cholesterol Integral proteins None of these
none of these
What molecule that protects against UV rays is found both in bacteria and in the eyes? Sphingolipids Carotenoid Triacylglycerol Cholesterol Water
carotenoid
What molecule has four fused rings in its structure? Sphingolipid Carotenoid Triacylglycerol Cholesterol Water
Cholesterol
In triacylglycerols, fatty acids are attached to glycerol via a/an______ linkage.
- O-CO-
- NH-
- O-NH-
- COO-
- C=C-
-O-CO
A lipid is \_\_\_\_\_\_\_\_\_\_. A fat A molecule that dissolves in a non-polar solvent Is made from isoprene units An oil made up of carbon and oxygens Is water soluble
A molecule that dissolves in a non-polar solvent
A particular fatty acid molecule has two bends, or kinks, in its structure. What is the cause of the bending or kinking?
Double bonds cause the fatty acids to bend or kink about in solution. These double bonds reduce the packing structure of fatty acids making them more liquid-like.
Where in the body are membranes found?
In the cell. The cell, itself, and the organelles have membranes.
One type of lipid is prominent in myelin sheaths. What is this the lipid and what is unique about its structure?
Sphingomyelins are a subtype of sphingolipids that occur in all membrane bilayers but are especially prominent in the myelin sheath of some neurons. This subclass of sphingolipids typically has a polar head group with a neutral charge. Another unique part of the structure is the ceramide linking of the fatty acid on carbon-2.
What molecules are storage fats? How do these molecules differ from those that make up cellular membranes?
Triacylglycerols are nonpolar molecules that can be stored as energy. They are a non-polar molecule (hydrophobic), so they do not interact with water. Phosphoglycerides, on the other hand, have both polar and nonpolar regions that permit them to interact with both polar and nonpolar environments making them perfect for membrane bilayers.
Which types of molecules are most likely to be present in membranes?
Phosphoglycerides, sphingolipids, cholesterol, and proteins are all found in the membrane. These molecules are all loosely associated with each other as described by the fluid mosaic model of the cellular membrane. They form a membrane bilayer.
In RNA, guanine always pairs with \_\_\_\_\_\_\_\_. Thymine Guanine Cytosine Uracil Both A and B
cytosine
DNA is built from which of the following? Nucleosides Genes Purines Nucleotide Codons
nucleotide
The structure of tRNA is held together, primarily, by which of the following? Hydrogen bonds London forces Covalent bonds Ion-dipole bonds Hydrogen covalent bonds
Hydrogen bonds
Which of the following pentose sugars is a constituent of B-DNA?
Xylose Ribitol Ribose Arabinose 2-deoxyribose
2 deoxyribose
Pyrimidines have \_\_\_\_\_\_\_\_ ring(s), (each) containing \_\_\_\_\_\_ nitrogen(s), whereas purines have \_\_\_\_\_\_\_\_ ring(s), (each) containing \_\_\_\_\_\_ nitrogen(s). 1; 1; 1; 1 1; 2; 2; 2 2; 2; 1; 2 2; 1; 1; 2 2; 2; 1; 1
1; 2, 2; 2
Which of the following nucleic acids is responsible for using the encoded genetic information to produce proteins found in living organisms? Peptide nucleic acid Ribonucleic acid Ribitol nucleic acid Deoxyribonucleic acid Glycerol nucleic acid
ribonucleic acid
Identify the complementary bases from the following. Adenine-Cytosine Adenine- Thymine Guanine-Thymine Guanine-Adenine Cytosine-Uracil
adenine-thiamine
How many hydrogen bonds are made between A and its complementary nucleotide? 1 2 3 4 5
2
The base sequence along one strand of DNA of 5’-GCATGAGCC-3’. What is the sequence of the complementary strand of DNA? 5’-CTAGTCCGC-3’ 3’-CGTACTCGG-5’ 3’-CTAGTCCGC-5’ 3’-CAGTCAGCT-5’ 5’-CTGACTACG-3’
3’- CGTACTCG-5’
Which of the following types of RNA functions as part of the complex that makes proteins? mRNA gRNA rRNA snRNA tRNA
rRNA
The \_\_\_\_\_\_\_\_ is the set of three sequential nucleotides that encodes for a particular amino acid. Anticodon Allele Gene Codon Chromosome
codon
A type of DNA that has a right-handed helix is the \_\_\_\_\_\_\_\_\_\_. A-form X-Form C-form L-form Z-form
A- form
Which of the following is a second messenger in cells? FAD cAMP AMP dATP UTP
cAMP
rRNA makes up about \_\_\_\_\_\_\_\_\_ percent of ribosomes.65 65 35 20 90 0
65
The conclusion that G and C are present in DNA in equimolar amounts is credited to \_\_\_\_\_\_. James Watson Francis Crick Erwin Chargaff Both A and B None of the above
Erwin Chargaff
The order of nucleotides in DNA is written \_\_\_\_\_\_\_\_\_\_. to C C to N 3’ to 5’ 5’ to 3’ Both C and D
5’ to 3’
In the Watson-Crick model for the double helix, which statement is NOT true?
The two strands run anti-parallel to one another
The base-pairing occurs on the inside of the double helix.
The double helix (B form) is right-handed.
Two equally sized grooves that run up the sides of the helix.
The two strands have complementary sequences.
Two equally sized grooves that run up the sides of the helix
Besides ATP, which other nucleotide is part of energy storage in cells? ATP UTP TTP CTP GTP
GTP
A major component of RNA but not DNA is: AMP GMP UMP CMP TMP
UMP
One strand of a double-helical DNA has the sequence (5’)GCGCAATATTCTCAAAATAT(3’).
A) Write the base sequence of the complementary strand.
B) Explain what complementary means in nucleic acid chemistry.
A. (3’)CGCGTTATAAGAGTTTTATA(5’)
B. The nucleotide sequences of complementary strands are such that, whenever an A occurs in one strand, there is a T in the other strand with which it can form a hydrogen-bonded base pair. Whenever a C occurs in one strand, a G occurs in the other. A is the base that is complementary to T, and C is the base complementary to G.
Briefly describe how noncovalent interactions contribute to the three-dimensional shapes and structures of RNA molecules.
Hydrogen bonding in regions of complementarity within an RNA chain can result in the formation of a structure. If no complementary regions exist, then an unstructured area will exist within the RNA.
In one sentence, identify the most obvious similarity between the A-form of DNA and the B-form of DNA.
Both A and B form a right-handed helix.
In nucleic acid chemistry, compounds that contain an organic nitrogen-containing base and a sugar are called ____A_____.
Two pyrimidine found in DNA in are _____B____ and ____B____.
A pyrimidine found in all DNA but not in RNA is ____C_____.
In DNA, the pair ____D_____ is held together by two hydrogen bonds.
In RNA, the pentose ______E______ serves as the monosaccharides.
A) Nucleosides
B) Cytosine and Thymine
C) Thymine
D) A-T
E) Ribose
The monomers of DNA nucleic acids, called nucleotides, consist of three parts. What are those three parts? (Give three)
phosphoric acid, deoxyribose (a pentose sugar), and an organic base.
True or False: The ΔG value for a particular reaction is -78kJ/mol. This value indicates the reaction is NOT spontaneous.
False
True or false: A biochemical metabolic pathway is a single reaction that converts starting material into products.
False
True or false: Two ATP molecules are used in the energy-investing stage of glycolysis.
True
True or False: The citric acid cycle occurs in the absence of oxygen.
False
True or false: The β-oxidation pathway degrades both even-numbered and odd-numbered fatty acids.
True
In converting glucose to pyruvate, how many ATP or NADH are produced (or required) in the 1,3-bisphosphoglycerate to 3-phosphoglycerate step in glycolysis? 2 ATP produced 1 ATP required 1 NADH produced 2 NADH and 1 ATP produced None of the above
2 ATP produced
In converting glucose to pyruvate, how many ATP or NADH are produced (or required) in the phosphoenolpyruvate to pyruvate step in glycolysis? 1 ATP required 1 ATP produced 2 ATP produced 2 ATP required None of the above
2 ATP produced
What is the primary reactant of glycolysis? Glucose Glucose-6-phosphate Fructose Fructose-6-phosphate Hexokinase
glucose
In glycolysis, when glucose enters a cell, it is immediately phosphorylated to form glucose-6-phosphate. The phosphate donor in this reaction is ATP, and the enzyme is \_\_\_\_\_\_\_\_. Hexokinase Aldolase CoA Phosphohexose isomerase None of the above
Hexokinase