Patho Quiz 1 Review.docx

Quiz 1 Study Guide
Questions
The function of a histone found in a eukaryote cell focuses on cellular:
Division
Movement
Activities
Deoxyribonucleic acid (DNA) folding Correct
An organelle that is responsible for the metabolism of cellular energy is referred to as a/an:
Golgi complex
Mitochondrion Correct
Endoplasmic reticulum
Nucleolus
Mitochondria play a role in cellular metabolism, cellular respiration, and energy production.

Which statement best describes a desmosome?
A desmosome is a barrier to diffusion.
Desmosomes hold cells together by continuous bands.
A desmosome is a communicating tunnel.
Desmosomes function as a zona occludens.

5. Which statement describes the function of a second messenger?
Extracellular ligand that binds with membrane-bound receptors
Intracellular enzyme that once will trigger a cascade of intracellular events
Chemical messenger that opens specific channels in the cell membrane
Chemical messenger that blocks a membrane-bound receptor signal
The binding of a ligand to a cell surface receptor triggers the activation of intracellular second messengers. Second messengers activate signal transduction pathways in the cell that can initiate different intracellular events. Cyclic adenosine monophosphate (cAMP) and calcium (Ca++) are the two major second-messenger pathways. First messengers are the extracellular ligands that bind to cell surface receptors. Binding of first messengers can result in the opening or closing of specific cell membrane channels or the activation of second messengers.

6. Which statement is correct regarding cellular energy?
Glycolysis is the building of sugar molecules.
Oxidative cellular metabolism is a single reaction making adenosine triphosphate (ATP).
Oxidative phosphorylation occurs in the mitochondria. Correct
Anaerobic glycolysis occurs in the presence of oxygen.
Oxidative phosphorylation occurs in the mitochondria. This is the mechanism by which the energy produced from carbohydrates, fats, and proteins is transferred to ATP.
Glycolysis is a process that breaks down glucose molecules; it produces a net of two ATP molecules.
Oxidation is a process during which a pair of electrons are removed and transferred. Oxidative cellular metabolism involves 10 biochemical reactions. Anaerobic glycolysis occurs in the absence of oxygen. Aerobic means in the presence of oxygen.
7. Movement of a solute molecule from an area of high concentration to an area of low concentration is called:
Diffusion
Filtration
Osmosis
Hydrostatic pressure
Diffusion is the movement of a solute from an area of high concentration to an area of low concentration. Osmosis is the movement of water down a concentration gradient from an area of higher water concentration to an area of lower water concentration. Filtration is the movement of water and solute through a membrane because of a greater pushing pressure on one side of the membrane than the other. Hydrostatic pressure is the mechanical force of water pushing against a cell membrane.
8. Which of the following is an example of an energy-releasing process?
Anabolism
Catabolism
Substrate-induced reaction
Second messenger system
Catabolism is an energy-releasing process. The energy-using process is anabolism. A substrate is a specific substance that is converted to a product in the reaction. A second messenger is a "pass-it-on signal." This occurs when a first messenger activates a receptor that then triggers a pass-it-on signal.
9. Which of the following describes the term chemotaxis?
Uses the second messenger system
Cellular signal affecting the cell of origin
Movement of cells along a chemical gradient
Ligands bind with receptors, triggering a second reaction
Chemotaxis is cellular movement along a chemical gradient caused by chemical attraction. Autostimulation is when a cell releases a signal that actually affects the cell of origin. A pass-it-on signal is a description for a second messenger system. A second messenger system is a means by which a ligand binds with receptors of a membrane system and then triggers a second system or reaction.
10. Which of the following describes an amphipathic molecule?
Hydrophobic and not Hydrophilic
Hydrophilic and not Hydrophobic
Hydrophobic and Hydrophilic
Nonpolar
The amphipathic molecule is both hydrophobic and hydrophilic. A hydrophilic molecule is a charged, water-loving molecule. A hydrophobic molecule is an uncharged or water-hating molecule. A polar molecule is another name for an amphipathic molecule.
11. Which of the following are functions of a protein? (Select all that apply.)
Pores or transport channels
Enzymes that drive pumps
Cell surface markers
Synapses for cells
Proteins may act as transport channels, pores, cell surface markers, enzymes that drive pumps, catalysts, and cell adhesion molecules (CAMs), or they may act as the key components of ATP synthesis. Synapses are the connections between two nerve cells.
12. Which of the following is the most common cause of cellular injury?
Free radical–induced injury
Chemical injury
Hypoxia
Mechanical factors
13. Common causes of edema formation (increased filtration of fluid from capillaries and lymph into surrounding tissues) include which of the following? (Select all that apply.)
Decreased hydrostatic pressure
Decreased plasma oncotic pressure
Increased capillary membrane permeability
Lymphatic obstruction
Sodium retention
The five common causes of increased edema are: (1) increased hydrostatic pressure, (2) decreased plasma oncotic pressure, (3) increased capillary membrane permeability, (4) lymphatic obstruction, and (5) sodium retention.

14. For a cell to engage in active transport process, it requires:
An expenditure of energy.
Appropriate fuel.
ATP.
All of the above are correct.


The simultaneous movement of two molecules in one direction is best described as:
A) symport.
B) antiport.
C) uniport.
D) passive transport.

Plasma proteins exert a force called:
A) filtration pressure.
B) hydrostatic pressure.
C) oncotic pressure.
D) hyperbaric pressure.

Cells respond to external stimuli by activation of a variety of signal transduction pathways. Signaling molecules cause all of the following except:

Acceleration/initiation of intracellular protein kinases
Arrest of cellular growth
Apoptosis
Conversion of an intracellular signal into an intracellular response


15. When considering water balance, which statement is the correct balance?
Isotonic fluids cause increased cellular swelling.
Hypertonic fluid causes increased cellular swelling.
Hypotonic fluid causes cellular swelling.
Hypernatremia causes cellular swelling.

The time period of the cell cycle during which RNA and protein synthesis occur is referred to as the:
A) G1 phase.
B) G2 phase.
C) M phase.
D) S phase.

The extracellular matrix is composed of: Select all that apply.
A) collagen.
B) elastin.
C) fibronectin.
D) desmosomes.
E) polypeptides.

The process by which nerve and muscle cells become more positive than negative is referred to as:
A) repolarization.
B) hyperpolarization.
C) depolarization.
D) action potentialization.

A function of signaling cascades includes message: Select all that apply.
A) transfer.
B) distribution.
C) deletion.
D) amplification.
E) modulation.

Hypotonic extracellular fluid (ECF) causes intracellular water gain and swelling. When the ECF is hypotonic, water moves from the intravascular space to the interstitial space, across the cell membrane, and into the cell. This action causes the cell to swell. An isotonic solution is equal to the plasma in concentration of solute molecules. Therefore no net water will move because equilibrium exists. The cell size is unchanged. A hypertonic fluid has excessive solute; therefore water will leave the cell and move into the vascular space to help balance this excess. Water leaving the cell results in cell shrinkage. Hypernatremia can occur with an acute gain in sodium or a loss of water, but generally it does not cause cellular swelling.

Lipid peroxidation- the destruction of unsaturated fatty acids (cell membrane), free radicals attacks cell membrane which causes the cellular membrane to be unstable.
Mechanism of cellular injury that can occur as a result of Hypoxia – a lack of sufficient oxygen is the single most common cause of cellular injury.

Mechanism of cellular injury that can occur as a result of free radicals -an electrically uncharged atom or group of atoms having an unpaired electron, making the molecule unstable so it steals one from another cell, causing damage.
Reactive oxygen - membrane damage can be caused by free radicals, especially by reactive oxygen species (ROS) causing oxidative stress. excess ROS overwhelms endogenous antioxidant systems.
Hyperlasia is an increase in the cell NUMBER resulting from an increased rate of cellular division. Different types of hyperplasia include: compensatory (mechanical), hormonal, pathologic (cells normal), atypical. It is caused by a response to injury after the injury has been severe and prolonged. Loss of epithelial cells and cells of the liver and kidney triggers DNA synthesis and mitotic division.
Metaplasia: The reversible replacement of one mature cell by another, sometimes less differentiated, cell type. Best example is replacement of normal columnar ciliated epithelial cells of the bronchial lining by stratified squamous epithelial cells. It's different from dysplasia because it is REVERSIBLE. It is caused by reprogramming of stem cells existing in most epithelia or of undifferentiated mesenchymal cells present in connective tissue. These precursor cells mature along a new pathway because of signals generated by cytokines and growth factors in the cell's environment.
Dysplasia- Abnormal cell size, shape, or organization of mature cells (NOT STEM). Dysplasia is not considered adaptive. It can be a strong predictor of breast cancer because these cells grow adjacent to cancerous cells. It is caused by the neoplastic growths that are found in epithelial tissue of the cervix and respiratory tract, adjacent to cancerous cells. IRREVERSIBLE

Cellular Communication and Signal Transduction
Cells communicate in three main ways: (1) they display plasma membrane–bound signaling molecules (receptors) that affect the cell itself and other cells in direct physical contact; (2) they activate receptor proteins inside the target cell, and the signal molecule has to enter the cell to bind to them; and (3) they form protein channels (gap junctions) that directly coordinate the activities of adjacent cells.
Primary modes of intercellular signaling are contact-dependent, paracrine, hormonal, neurohormonal, and neurotransmitter.

Signal transduction involves signals or instructions from extracellular chemical messengers that are conveyed to the cell's interior for execution.
Signal transduction pathways (signaling cascades, relay chains) have several important functions, including physically transferring the signal around the cell, amplifying the signal, distributing the signal, and modulating the signal.
Two important second messenger pathways are cAMP and Ca2+.

G protein is an intermediary between the receptor and adenylyl cyclase.
Phospholipase C, an enzyme protein effector, is bound to the inner side of the membrane.
Membrane Transport: Cellular Intake and Output
Water and small, electrically uncharged molecules move through pores in the plasma membrane's lipid bilayer in the process called passive transport.
Passive transport does not require the expenditure of energy; rather, it is driven by the physical effects of osmosis, hydrostatic pressure, and diffusion.

Larger molecules and molecular complexes (e.g., ligand-receptor complexes) are moved into the cell by active transport, which requires expenditure of energy (by means of ATP) by the cell.

Hydrostatic pressure is the mechanical force of water pushing against cellular membranes.
Osmosis is the movement of water across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.
The amount of hydrostatic pressure required to oppose the osmotic movement of water is called the osmotic pressure of the solution.
The overall osmotic effect of colloids, such as plasma proteins, is called the oncotic pressure or colloid osmotic pressure.