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