Proteins
Which part of an amino acid determines it's polarity?
a. central (hydro)carbon
b. carboxyl group
c. amine group
d. "R" group
d. "R" group
**ALL amino acids have the exact same structure EXCEPT for the "R" group.
Which type of transport does not require energy and flows down the gradient?
A. Active Transport
B. Passive Transport
C. Bulk Transport
D. Secondary Active Transport
B. Passive Transport
This site serves as the synthesis and assembly of ribosomes?
a. Peroxisome
b. Plasma membrane
c. Chromatin
d. Nucleolus
d. Nucleolus
True or False. The cell wall is the plasma membrane of prokaryotic organisms.
False.
**The plasma membrane is a flexible covering that protects the inside of a cell from the environment outside a cell. The cell wall is a stiff structure outside the plasma membrane that protects a cell from attack by viruses and other harmful organisms.
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.
Peptide bonds are covalent bonds which link amino acids together to form a polypeptide chain. The is due to the removal of hydroxyl from the _______ and the hydrogen from the _______.
a. N-terminus; N-terminus
b. N-terminus; C-terminus
c. C-terminus; N-terminus
d. C-terminus; C-terminus
c. C-terminus; N-terminus
The following make up part of the cell membrane except for:
a. Proteins
b. Carbohydrates
c. Nucleic acids
d. Lipids
c. Nucleic acids
Eukaryotic cells are able to utilize fatty acids for energy. _______ in our cells are able to breakdown the peroxides generated from the metabolism of these fatty acids and convert it to water.
a. rough ER
b. smooth ER
c. lysosomes
d. peroxisomes
d. peroxisomes
____________ bacteria lack an outer membrane but are surrounded by thick layers of peptidoglycan. ___________ bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide.
a. Gram +; Gram -
b. Gram +; Gram +
c. Gram -; Gram +
d. Gram -; Gram -
a. Gram +; Gram -
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.
The secondary structure of proteins are stabilized by hydrogen bonds within the polypeptide backbons. The tertiary structure arises from interactions between _____.
a. many polypeptides
b. "R" groups
c. the polypeptide backbone
d. peptide bonds
b. "R" groups
This is a type of passive transport that uses proteins embedded in the membrane to bring things into the cell.
A. Facilitated Diffusion
B. Simple Diffusion
C. Primary active transport
D. Na+/K+ pump
A. Facilitated diffusion
True or False. Prokaryotes can convert light energy to chemical energy through photosynthesis because they have chloroplast.
False.
**Chloroplast is an organelle.
Which type of cytoskeleton fiber does not have dynamic instability?
a. microfilaments
b. intermediate filaments
c. microtubules
d. none of the above
b. intermediate filaments
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
Which among the following structures is not affected when a protein denatures?
a. Primary
b. Secondary
c. Tertiary
d. Quaternary
a. Primary
**Denaturation reactions are not strong enough to break the peptide bonds; the primary structure (sequence of amino acids) remains the same after a denaturation process.
A plant cell is placed in a hypertonic solution. What will happen to the cell?
a. It will lyse.
b. It will shrivel.
c. It will have increased turgor pressure.
d. It will plasmolyze.
d. It will plasmolyze.
Which of the following structures are not part of the endomembrane system:
a. Plasma membrane
b. Vesicles and Vacuoles
c. Peroxisomes
d. Lysosomes
e. Golgi apparatus.
f. ribosomes
g. Endoplasmic reticulum
c. Peroxisomes
f. ribosomes
The cell junctions respectively that exclude the passage of water between cells, maintain tissue form and strength, and allow the exchange of small molecules between cells are:
a. desmosomes, tight junctions and gap junctions.
b. tight junctions, gap junctions, and tight junctions.
c. gap junctions, tight junctions, and desmosomes.
d. tight junctions, desmosomes, and gap junctions.
d. tight junctions, desmosomes, and gap junctions.
Where does energy production take place in bacteria that can perform aerobic metabolism?
a. Mitochondria
b. Nucleus
c. Plasma Membrane
d. Glycocalyx
c. Plasma Membrane
**Bacteria, like eukaryotes, rely on a concentration gradient to drive an ATP synthase molecule. Bacteria are prokaryotes, and do not have membrane-bound organelles. Energy production in bacteria takes place across the plasma membrane, with the gradient between the extra- and intracellular environment providing the appropriate concentration gradient.
List four protein functions.
a. Enzymes
b. Defensive proteins
c. Storage proteins
d. Transport proteins
e. Hormonal proteins
f. Receptor/Signaling proteins
g. Motor proteins
h. Structural support
______ is the driving force for primary active transport. _______ is the driving force for secondary active transport.
a. ATP; ATP
b. ATP; Electrochemical gradient
c. Electrochemical gradient; ATP
d. Electrochemical gradient; Electrochemical gradient
b. ATP; Electrochemical gradient
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.
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.
Tay-Sachs disease is a genetic disorder that causes certain lipids known as gangliosides to accumulate in the neurons of the brain and spinal cord. As the gangliosides build up, neurons rapidly degenerate. Which of the following cell structures is most likely associated with the accumulation of gangliosides?
a. Nucleus
b. Lysosomes
c. Mitochondria
d. ER
b. Lysosomes
**Lysosomes digest excess materials, such as accumulated gangliosides. If gangliosides accumulate, it is likely due to lysosomal dysfunction.