Macromolecules
A polysaccharide you are studying contains unbranched β glucose molecules and cannot be digested by humans. Which polysaccharide are you studying?
a) glucose
b) glycogen
c) cellulose
d) starch
c) cellulose
CENTRAL DOGMA: DNA is _____ into an mRNA strand, which is then _____ into a protein.
a. replicated; translated
b. transcribed; translated
c. translated; replicated
d. translated; transcribed
b. transcribed; translated
Which of the following statements does not support the Cell Theory?
a. Cells are the fundamental unit of structure and function.
b. Cells contain hereditary information.
c. Cells are formed spontaneously.
d. Energy flow occurs in the cell.
c. Cells are formed spontaneously.
True or False. Prokaryotes can convert light energy to chemical energy through photosynthesis because they have chloroplast.
False.
Chloroplast is an organelle. Prokaryotes do not have organelles. Many prokaryotes are photosynthetic, but they do not use a chloroplast to perform photosynthesis.
During cell communication in the nervous system, chemical messengers called neurotransmitters travel between neurons. As they travel, neurotransmitters send messages from one neuron to another. Which of the following best describes the role of neurotransmitters in cell-to-cell communication?
a. Neurotransmitters are local regulators that allow neurons to communicate over short distances.
b. Neurotransmitters are local regulators that allow neurons to communicate over long distances.
c. Neurotransmitters are long-distance signaling molecules that allow neurons to communicate over short distances.
d. Neurotransmitters are long-distance signaling molecules that allow neurons to communicate over long distances.
a. Neurotransmitters are local regulators that allow neurons to communicate over short distances.
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. carbohydrates
b. cholesterol
Along an RNA strand, the phosphodiester bond involves ________.
a. Ribose and phosphate
b. Deoxyribose and phosphate
c. Ribose and nitrogenous base
d. Deoxyribose and nitrogenous base
a. Ribose and phosphate
The following macromolecules can make up part of the cell membrane except for:
A. Proteins
B. Carbohydrates
C. Nucleic Acids
D. Lipids
C. Nucleic Acids
Which of the following would not make the cell membrane more fluid?
a. saturated hydrocarbon chains
b. unsaturated hydrocarbon chains
c. cholesterol
d. both A & B
a. saturated hydrocarbon chains
Epinephrine will bind to GPCR which in turn activates the G protein. The G protein will activate the adenylyl cyclase which converts ATP to cAMP. cAMP will initiate the signal transduction phase by activating the first kinase in the phosphorylation/dephosphorylation series. In this example, epinephrine is the _____ messenger and cAMP is the _____ messenger.
a. first; first
b. first; second
c. second; first
d. second; second
b. first; second
Which of the following is not a function of a lipid?
a. Energy storage
b. Cushions organs and insulates the body.
c. Carries water-soluble vitamins.
d. Supplies essential fatty acids.
c. Carries water-soluble vitamins.
Which of the following statements regarding DNA is false?
a. It is a permanent blueprint of life.
b. It is double stranded and contains a deoxyribose sugar.
c. It contains the bases A, T, C, and G.
d. The backbone of the DNA molecule is held together by hydrogen bonds.
d. The backbone of the DNA molecule is held together by hydrogen bonds.
Mutations can change the overall structure of proteins. Predict the outcome of a harmful mutation that modifies the microfilaments of the cytoskeleton of a white blood cell.
a. It would improve the structural support of the cell.
b. It would decrease it's ability to phagocytose other cells.
c. It would allow for better interaction with motor proteins for improved cell motility.
d. It would allow cilia or flagella to form.
b. It would decrease it's ability to phagocytose other cells.
The function of which cellular structure would be least affected by a malfunctioning Golgi apparatus?
a. Endoplasmic reticulum
b. Lysosome
c. Plasma Membrane
d. Secretory vesicles
a. Endoplasmic reticulum
**The function of the endoplasmic reticulum occurs before the proteins reach the Golgi, so it would be the least affected of the choices above.
What is an example of long-distance endocrine signaling?
a. Neurotransmitters being secreted across a synapse to stimulate a muscle cell.
b. Cells transporting nutrients through gap junctions.
c. Pancreas releasing insulin into the blood.
d. A cell secreting interleukins to itself.
c. Pancreas releasing insulin into the blood.
Which of the following statements is incorrect?
a. A single strand of DNA or RNA is held together by covalent bonds.
b. The two strands of DNA are held together by hydrogen bonds.
c. Nucleic acids are synthesized in the 3' to 5' direction.
d. Nucleotides are added to the 3' end of a polynucleotide.
c. Nucleic acids are synthesized in the 3' to 5' direction.
Which of the following bonds will not help in forming the tertiary structure of a protein?
a. hydrogen bonds
b. disulfide bridges
c. peptide bonds
d. Van der Waals bonds
c. peptide bonds
A cell is treated with a toxin that prevents the synthesis of new lysosomes. However, the cell continues to produce the hydrolytic enzymes normally found in lysosomes. In which of the following structures are the hydrolytic enzymes most likely to accumulate?
a. Golgi apparatus
b. mitochondria
c. nucleus
d. Smooth ER
a. Golgi apparatus
**Lysosomes are synthesized by the Golgi apparatus. If new lysosomes aren’t synthesized, and the hydrolytic enzymes continue to be produced, the hydrolytic enzymes will accumulate in the Golgi apparatus.
Neighboring cells in tissues adhere and communicate through direct physical contact. Which cell junction connect adjacent plasma membranes in animal cells and allow for direct communication between cells?
a. Tight Junctions
b. Gap Junctions
c. Desmosomes
d. Plasmodesmata
b. Gap Junctions
Ligands are signaling molecules that can elicit a cellular response. The ligands that membrane receptors bind to outside of the cell are _____, while the ligands that intracellular receptors bind to in the cytosol are small & _____.
a. hydrophobic; hydrophilic
b. hydrophobic; hydrophobic
c. hydrophilic; hydrophilic
d. hydrophilic; hydrophobic
d. hydrophilic; hydrophobic
Sickle-cell disease occurs due to the substitution of a single amino acid. Which level(s) of protein structure is affected?
a. primary
b. primary and secondary
c. primary, secondary, and tertiary
d. primary, secondary, tertiary, and quaternary
d. primary, secondary, tertiary, and quaternary
Complete the complementary DNA sequence:
5' AGTGGCTA 3'
a. 3' UCACCGAU 5'
b. 5' UCACCGAU 3'
c. 3' TCACCGAT 5'
d. 5' TCACCGAT 3'
c. 3' TCACCGAT 5'
A couple is told by their doctor that the reason why they cannot have children is that the sperm of the male lack motility because it does not have the structures responsible for propulsion. Which cellular structures are likely to be the underlying cause of this lack of motility?
a. microfilament
b. intermediate filaments
c. microtubules
d. vacuoles
c. microtubules
A student uses a microscope to compare a human skeletal muscle cell and a human epithelial cell. The student observes that the muscle cell has more mitochondria than the epithelial cell. Which of the following conclusions is best supported by this observation?
a. The muscle cell does not require ATP to function.
b. The epithelial cell does not require ATP to function.
c. The muscle cell requires more ATP than the epithelial cell.
d. The epithelial cell requires more ATP than the muscle cell.
c. The muscle cell requires more ATP than the epithelial cell.
A mutation causes the extracellular domain of a G protein-coupled receptor (GPCR) to be misfolded. The misfolded GPCR is packaged into a vesicle that travels to the cell membrane. Upon reaching the cell membrane, the vesicle deposits the misfolded GPCR, which fuses with the cell membrane and functions as a membrane receptor.
a. The intracellular domain of the misfolded GPCR will change from an inactive to an active shape.
b. The extracellular domain of the misfolded GPCR will begin a signal transduction pathway.
c. The ligand-binding domain of the misfolded GPCR will not bind with it's specific ligand.
d. The intracellular domain of the misfolded GPCR will not bind with it's specific ligand.
c. The ligand-binding domain of the misfolded GPCR will not bind with it's specific ligand.
(The ligand-binding domain of a GPCR must have the correct shape to bind with its ligand. If the GPCR is misfolded, the ligand-binding domain will change shape. As a result, the domain will no longer be able to bind with its specific ligand).