Acids, Bases, & pH
Carbon
Carbohydrates
Lipids
Nucleic Acids
100
One water molecule in ~500 million naturally dissociates into a hydrogen ion and a hydroxide ion. Which of the following denotes a hydroxide ion?
a. H2O
b. H+
c. OH-
d. H3O+
c. OH-
100
True or False.
Functional groups give the molecule it's attached to unique properties.
TRUE
100
True or False.
Monosaccharides can be broken down into smaller sugars.
False.
Monosaccharides are simple carbohydrates consisting of one carbohydrate unit.
100
Which lipid makes up the cell membrane?
a. triglycerides
b. cholesterol
c. phospholipids
d. steroids
c. phospholipids
100
True or False.
DNA is double stranded. These strands are parallel and complementary.
False.
200
As the concentration of hydrogen ions increases, the pH ________. As the concentration of hydroxide ions decreases, the pH _________.
a. decreases; decreases
b. decreases; increases
c. increases; decreases
d. increases; increases
a. decreases; decreases
200
How many carbon atoms does this molecule have?
a. 5
b. 7
c. 10
d. 12
b. 7
200
What is the molecular formula of an oligosaccharide made up of five hexose sugars?
a. C30H60O30
b. C30H52O30
c. C30H52O26
d. C30H68O34
c. C30H52O26
200
Which type of lipid consists of a glycerol molecule covalently bonded, via an ester linkage, to three fatty acid molecules?
a. triglycerides
b. cholesterol
c. phospholipids
d. steroids
a. triglycerides
200
It refers to the DNA sequence that codes for a specific protein.
a. Genome
b. Gene
c. DNA
d. RNA
b. Gene
300
True or False.
The Carbonic Acid-Bicarbonate buffer system is the most important buffer for maintaining the pH homeostasis of our blood. This buffer system works by neutralizing our pH level.
False.
A buffer system does not keep a solution neutral. It STABILIZES the solution to keep it in the desired pH range.
300
Identify the functional group present in the image above. Is it polar or nonpolar?
a. carbonyl, polar
b. carbonyl, nonpolar
c. carboxy, polar
d. carboxy, nonpolar
a. carbonyl, polar
300
Monosaccharides are the building blocks of carbohydrates. Which of the following is the covalent bond that holds monosaccharides together?
a. ester linkages
b. peptide bonds
c. phosphodiester linkages
d. glycosidic linkages
d. glycosidic linkages
300
Which of the following is a precursor to reproductive hormones, and is responsible for maintaining the fluidity of our cell membranes?
a. triglycerides
b. cholesterol
c. phospholipids
d. steroids
b. cholesterol
300
Polynucleotides are held together via phosphodiester linkages. The hydroxyl group of the pentose at the ___ carbon of one nucleotide is covalently bonded to the phosphate group at the ___ carbon of another nucleotide.
a. 5'; 5;
b. 3'; 5'
c. 5'; 3'
d. 3' 3'
b. 3'; 5'
400
Milk has a pH of 6. Soda has a pH of 3. Which of the two is more acidic and by how much more?
a. Milk; 3x
b. Milk; 1,000x
c. Soda; 3x
d. Soda; 1,000x
d. Soda; 1,000x
400
Glucose molecules can be covalently bonded to other glucose molecules to form a polysaccharide. Glucose is considered to be the:
a. macromolecule
b. polymer
c. monomer
d. hydrocarbon
c. monomer
400
Compare the following polysaccharides according to function and kingdom use/location: glycogen, starch and cellulose.
Glycogen - energy storage in animals (particularly in the muscles and livers in humans)
Starch - energy storage in plants
Cellulose - provides structure, shape, and support in plants
400
Saturated fats tend to be _____ in room temperature. Unsaturated fats tend to be ______ in room temperature.
a. liquid, liquid
b. liquid, solid
c. solid, liquid
d. solid, solid
c. solid, liquid
400
Nucleotides are made of a phosphate group, a pentose sugar, and a nitrogenous base. Identify the pentose (ribose or deoxyribose) and nitrogenous base (purine or pyrimidine).
a. ribose, purine
b. ribose, pyrimidine
c. deoxyribose, purine
d. deoxyribose, pyrimidine
c. deoxyribose, purine
500
An aqueous solution has an [OH-]= 10-5. Calculate the [H+] and pH.
a. [H+]= 1x10-9; pH=5
b. [H+]= 1x10-9; pH=9
c. [H+]= -9; pH=5
d. [H+]= -9; pH=9
b. [H+]= 1x10-9; pH=9
500
Which reaction is involved in the synthesis of polymers?
a. hydrolysis
b. dehydration
c. hydrogenation
d. neutralization
b. dehydration
500
Give at least three functions of carbohydrates.
*immediate energy source (glucose)
*energy storage (starch in plants, glycogen in animals)
*structural support (cellulose, chitin)
*cell communication (glycolipids, glycoproteins)
500
Which of the following is a defining characteristic among lipids?
a. lipids are polar
b. lipids are amphipathic
c. lipids are hydrophilic
d. lipids are hydrophobic
d. lipids are hydrophobic
500
A DNA molecule is 26% cytosine. Following Chargaff's rule, the molecule is ___ thymine and ___ guanine.
a. 24%; 52%
b. 48%; 24%
c. 24%; 26%
d. 48%; 52%
c. 24%; 26%