Chapter 3 Flashcards
Which of the following is true regarding the generation of a membrane potential?
Both potassium and sodium ions can “leak” through the cell membrane due to diffusion.
Which statement best describes transcytosis?
transporting an endoscope from one side of a cell to the other and releasing the contents by exocytosis.
In certain kinds of muscle cells, calcium ions are stored in
the smooth ER
The RNA, responsible for bringing the amino acids to the “factory” site for protein formation is
tRNA
A red blood cell placed in pure water would
swell and burst
Which of the following describes the plasma membrane?
the phospholipid bilayer surrounding the cell
Which of these is NOT a function of the plasma membrane?
it prevents potassium ions from leaking out and sodium ions from crossing into the cell.
Which structures are fingerlike projections that greatly increase the absorbing surface of cells?
microvilli
Which of the following statements is correct regarding diffusion?
The greater the concentration of gradient, the faster the rate of diffusion
Cell junctions that promote the coordinated activity of cells by physically binding them together into a cell community include all of the following except
peroxisomes
If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen?
the cells will lose water and shrink
Which of the following is NOT a sub cellular structure?
Intercellular material
Once solid material is phagocytize and taken into a vacuole, which of the following statements best describes what happens?
A lysosome combines with the vacuole and digests the enclosed solid material.
Riboswitches are folded RNAs that act as switches to turn protein synthesis on or off in response to
changes in the environment
Which of the following is a function of a plasma membrane protein?
molecular transport through the membrane
Which of the following statements is correct regarding RNA?
Messenger RNA, transfer RNA, and ribosomal RNA play a role in protein synthesis
Which of the following would NOT be a constituent of a plasma membrane?
messenger RNA
Mitosis
produces nucleus replication
The electron microscope has revealed that one of the components within the cell consists of microtubules arranged to form a hollow tube. This structure is a
centriole
Which of these is an inclusion, NOT an organelle?
melanin
Which of the following is NOT a factor that binds cells together?
glycolipids in the glycocalyx
If the nucleotide or base sequence of the DNA strand used as a template for messenger RNA synthesis is ACGTT, then what would be the sequence of bases in the corresponding mRNA?
UGCAA
Which transport process is the main mechanism for the movement of most macromolecules by body cells?
receptor-mediated endocytosis
Caveolae are closely associated with all but which of the following?
enzymes involved in cell metabolism
Passive membrane transport processes include
movement of a substance down its concentration gradient
Enzymes called ___ destroy the cell’s DNA and cytoskeleton, producing a quick death of the cell.
caspases
Mitochondria
contain some of the DNA and RNA code necessary for their own function
Ribosomes, endoplasmic reticulum, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export) only, never for use by the cell. This statement is
false; integral cell membrane proteins are also synthesized this way
Peroxisomes
are able to detoxify substances by enzymatic action
DNA replication
takes place during interphase of the cell cycle
Which statement is the most correct regarding transcription/translation?
The nucleotide sequence in the tRNA anticodon is an exact copy of the DNA triplet that coded for it except that uracil is substituted for thymine.
In the maintenance of the cell resting membrane potential
extracellular sodium levels are high
Which of the following is a concept of the cell theory?
a cell is the basic structural and functional unit of living organisms
Which of the following does not serve as a signal for cell divine?
repressor genes
Which of the following is a principle of the fluid mosaic model of cell membrane structure?
Phospholipids form a bilayer that is largely impermeable to water-soluble molecules.
Which of the following statements is more correct regarding the intracellular chemical signals known as “second messengers”?
Cyclic AMP and calcium may be second messengers
The main component of the cytosol is
water
Lysosomes
contain acid hydrolyses that are potentially dangerous to the cell
The endomembrane system is
an interactive system of organelles whose membranes are physically or functionally connected
The functions of centrioles include
organizing the mitotic spindle in cell division
The gene can best be defined as
a segment of DNA that carries the instructions for one polypeptide chain
Extracellular matrix is
the most abundant extracellular material
Crenation is likely to occur in blood cells in
a hypertonic solution
Some hormones enter cells via
receptor-mediated endocytosis
If a tRNA had an AGC anticodon, it would attach to a(n) _____ mRNA codon.
UCG.
