Bio Module 3
Redox reaction
A local regulator is a signaling molecule that diffuses through the interstitial fluid, the fluid surrounding the cells, and acts on nearby cells. What is this process?
nucleus
A single cell in a smoker's lung has become cancerous. It doubles its DNA and divides much faster than a normal lung cell. The most likely change that would have caused this condition took place in the:
Hormones
Consider the cellular process illustrated in the accompanying figure. What substance would most likely be transported in this manner?
degrade the pathogens with hydrolytic enzymes for later export from the cell
During an infection, white blood cells travel to the infected site and phagocytize the pathogens. After phagocytosis, primary lysosomes fuse with the phagocytic vesicle to form a larger vesicle called a secondary lysosome. The purpose for this process is to:
the basic similarities in cell structure and chemistry
Evidence that all living cells have a common origin is best illustrated by:
A gap junction provides communication between cells.
How do gap junctions differ from desmosomes?
The SEM yields a 3D image of the object being studied.
How does the scanning electron microscope differ from the transmission electron microscope?
Protein synthesis
If a bacterial toxin destroys ribosomes, what cellular activity will be affected first?
centrioles
In many cells, including almost all animal cells, the centrosome contains two structures called _________.
False
In scanning electron microscopy, an electron beam passes through a very thin slice of a specimen and then falls onto a photographic plate or a fluorescent screen
They allow the transport of small molecules and ions between adjacent cells.
In the accompanying figure, what is the role of the structures between the membranes?
The protein kinase activates a cellular response.
In the cAMP signal transduction pathway, a protein kinase is activated. What happens next?
False
Insulin stimulates cells to take in glucose by facilitated diffusion, so the down regulation of insulin receptors increases the ability of cells to take in glucose. __________________
True
Ion channels are found in the plasma membranes of neurons and muscle cells.
Cytoplasm
Name the part of the cell outside the nucleus.
False
Peroxisomes are found in large numbers in cells that synthesize, store, and degrade lipids, and one of their functions is to break down protein molecules.
false
Peroxisomes are found in large numbers in cells that synthesize, store, and degrade lipids, and one of their functions is to break down protein molecules.
microtubules
Peroxisomes are found in large numbers in cells that synthesize, store, and degrade lipids, and one of their functions is to break down protein molecules.
lysosomes
Plants lack organ systems for disposing of toxic metabolic waste products. Their cells' vacuoles are similar to which animal cell organelle?
False
Plasmolysis occurs in plant cells when the soil or water contains low concentrations of salts or fertilizers.
organelles.
Specialized structures within a living cell are known as ___________.
protein synthesis
The cellular structure indicated by the arrow in the accompanying figure is responsible for:
dynein; ATP
The force necessary to cause microtubules of cilia and flagella to slide alongside one another is provided through the action of ____ proteins, which derive the energy to perform their work directly from ____ molecules.
True
The many short appendages that a cell has are called cilia.
True
The micrometer (μm) is the most convenient unit for measuring cells.
signaling molecule; G protein
The outer part of a G protein-linked receptor binds to a(n) ____, and its inner part binds to a(n) ____.
The concentration of a hormone is too high.
Under which of the following situations would receptor downregulation most likely occur?
microfilaments
rodlike structures consisting of actin
black and white
What are the colors of an electron micrograph?
chloroplast−storage of enzymes
Which cellular structure is correctly matched to the role it plays within the cell?
flagellum
A basal body anchors what part of a cell?
true
Kinesin transports organelles toward the minus end of a microtubule.
Golgi complex
Proteins that are synthesized by ribosomes may be further modified within which organelle?
Accepting vesicles from the ER
The cis face of the Golgi complex is most directly involved in which process?
molecular chaperones
What enzyme in the ER lumen catalyzes the efficient folding of proteins into proper conformations?
The binding of glucose triggers a conformational change in the carrier protein.
What have studies of glucose transport in liposomes revealed?
plasma membrane
What is a characteristic found in both prokaryotic and eukaryotic cells?
middle lamella
What is found between the primary walls of adjacent cells which cause them to tightly adhere to one another?
2000
What is generally the maximum magnifying capacity of a light microscope?
transformation of energy
What is the primary function of mitochondria?
To increase surface area
What is the purpose of the cristae of the inner membrane of mitochondria?
Neurotransmitters
What type of chemical compound diffuses across synapses?
confocal microscopy
What type of microscopy uses a laser to excite fluorophores in a thin "slice" through a cell?
Integrins
What type of protein can transduce a signal in two directions?
Acetylcholine
Which molecule is a first messenger but not a second messenger?
Acetylcholine
Which neurotransmitter opens ligand-gated sodium channels?
mitochondria
Which of the following organelles plays an important role in apoptosis, or programmed cell death?
mitotic spindle
Which of the following serves as a framework for the orderly distribution of chromosomes during cell division?
micrometer
Which one of these are the most convenient unit for measuring cells?
Plasma membranes prevent communication with other cells.
Which statement about plasma membranes is false?
Cell fractionation
Which technique is used to separate different part of cells so that they can be studied by both physical and chemical methods?
actin filaments
While testing an experimental drip on a vertebrate cell, you notice that the cell cortex becomes more fluid and the cell loses its ability to move. Despite this, you determine that cell strength is maintained. Based on these observations, you correctly conclude that the drug most directly affects:
It is slightly amphipathic because of the presence of one hydroxyl group.
Why can cholesterol act as a "fluidity buffer" in cell membranes?
A small cell has a small volume relative to surface area, which allows efficient transport through the plasma membrane.
Why is it advantageous for cells to be small?
Nucleolus
granular body within an organelle which consists of RNA and protein
lysosome
membranous sacs in animals