Chapter 2
What statement made by the student nurse demonstrates that teaching about the Kreb's cycle has been effective?
"It provides the final common pathway for the metabolism of nutrients." Explanation: The Krebs cycle provides the final common pathway for the metabolism of nutrients. Glycolysis is the process by which energy is liberated from glucose.
Select the type of energy production that occurs in the mitochondria with the Krebs cycle. Glycolysis Anaerobic glycolytic pathway Glyconeogenesis Aerobic metabolism
Aerobic metabolism Explanation: Two types of energy production are present in the cell: (1) the aerobic (i.e., with oxygen) pathway occurring in the mitochondria and involving the citric acid cycle (Krebs cycle), and (2) the anaerobic (i.e., without oxygen) glycolytic pathway, occurring in the cytoplasm. Glycolysis is the anaerobic process by which energy is liberated from glucose. It is an important source of energy for cells that lack mitochondria.
What concept will the nurse need to explain to a client with cancer about the purpose and action of chemotherapy? Pinocytosis Apoptosis Osmosis Depolarization
Apoptosis Explanation: Cancer is a condition in which cells experience dysregulated apoptosis as the cells fail to age and die. Chemotherapy stimulates these cells to increase their rate of death. Pinocytosis is when a cell engulfs small solid or liquid substances from the surrounding environment. Osmosis is fluid moving across a cell membrane and is not directly related to chemotherapeutic impact on cells. Depolarization has to do with electrical impulse transmission and is not directly correlated with chemotherapy.
A client with a complete tear of the rotator cuff in the right shoulder was given the choice between surgery and stem cell transplant. The client chose to try the stem cell injection. The client asked the health care provider, "How does this work on my shoulder?" The best response would be: In addition to stem cells, the physician will give you some growth factor to help your body build more muscle mass. The stem cells will circulate through your arterial system and come to rest in any area that is inflamed and in need of repair. Bone marrow stem cells have been shown to generate cartilage, bone, and muscle when injected directly into the injured site. Stem cell injection is similar to a blood transfusion in that the cells will bring more oxygen and nutrients to the damaged tissue.
Bone marrow stem cells have been shown to generate cartilage, bone, and muscle when injected directly into the injured site. Explanation: Whether adult stem cells have a differentiation capacity similar to that of embryonic stem cells remains the subject of current debate and research. Thus far, bone marrow stem cells have been shown to have very broad differentiation capabilities, being able to generate not only blood cells but also fat, cartilage, bone, endothelial, and muscle cells.
Cadherins, selectins, and some integrins, which are adhesion molecules, depend on which of the following to function in cell adhesion? Calcium Potassium Sodium Iron
Calcium Explanation: Important classes of extracellular macromolecules are the adhesion molecules that maintain intercellular contacts. There are three classes of adhesion molecules that depend on extracellular calcium to function in cell adhesion: cadherins, selectins, and integrins (some of which are magnesium dependent).
6m 55s Report this Question Aerobic metabolism, also known as oxidative metabolism, provides energy to the body by which process?
Combining hydrogen and oxygen to form water Explanation: Oxidative metabolism takes place in the electron transport chain in the mitochondria. During oxidative reactions, proteins combine with O2 to form water, and large amounts of energy are released and used to add a high-energy phosphate bond to ADP, converting it to ATP. Aerobic metabolism involves the combination of carbon ions from dietary nutrients, hydrogen ions, and oxygen. The result is carbon dioxide and water as energy is released, which is stored in ATP. Phosphate bonds are added (not removed) to ADP to form ATP. Pyruvate is formed from glucose in the anaerobic process of glycolysis and is converted to lactic acid during anaerobic metabolism.
Select the option that best describes the nucleus of the cell. Carries and copies DNA instructions for protein synthesis to the cytoplasm. Transforms organic compounds into energy that is accessible to the cell. Contains the site for RNA synthesis that ultimately is essential for protein synthesis. Breaks down and digests worn-out parts of the cell.
Contains the site for RNA synthesis that ultimately is essential for protein synthesis. Explanation: The nucleus is the site for the synthesis of the three main types of RNA. These RNA molecules move from the nucleus to the cytoplasm and carry out the synthesis of proteins that is essential for the cell to stay alive. The messenger RNA copies and carries the DNA instructions. The mitochondria transform compounds into energy. The lysosomes break down excess and worn-out cell parts as well as foreign substances that are taken into the cell
When exercising outside on an extremely warm day, the client can feel his heart pounding very rapidly. Thinking in terms of the ability of the aorta to stretch to accommodate more blood circulating during exercise and the warm environment, this is an example of the function of which fibrous protein? Ligaments Elastin Reticular Collagen
Elastin Explanation: Three types of fibers are found in the extracellular space: collagen, elastin, and reticular fibers. Elastin acts like a rubber band; it can be stretched and then returns to its original form. Elastin fibers are abundant in structures subjected to frequent stretching, such as the aorta and some ligaments. Collagen is the most common protein in the body. It is a tough, nonliving, white fiber that serves as the structural framework for skin, ligaments, tendons, and many other structures. Reticular fibers are extremely thin fibers that create a flexible network in organs subjected to changes in form or volume, such as the spleen, liver, uterus, or intestinal muscle layer.
Which form of signal transduction resulting from ligand-receptor binding has the potential to produce effects in the entire body system?
Endocrine Explanation: Cells communicate in several ways. In endocrine signaling, the cells release chemical mediators (hormones) that enter the bloodstream, then bind to cell receptors throughout the body. A ligand is a substance with a high affinity for the receptor. In autocrine signaling, a cell releases a chemical to the extracellular fluid, which changes its own activity. In paracrine signaling, a cell releases a chemical to the extracellular fluid, but enzymes rapidly metabolize the chemicals so they only act on nearby cells.
When discussing the various functions of the cellular parts, the pathophysiology professor asks a group of students, "Where are the primary sites of protein synthesis located in a cell?" Which student response is correct? Lysosomes Endoplasmic reticulum Mitochondria Nuclear envelope Peroxisomes
Endoplasmic reticulum Explanation: The endoplasmic reticulum (with its associated ribosomes) and Golgi apparatus represent the primary sites of protein synthesis in the cell.
The cytoplasm surrounds the nucleus of the cell and contains organelles. Select the organelles found in the cytoplasm. Select all that apply. Endoplasmic reticulum Golgi apparatus Mitochondria Lysosomes Cytoskeleton
Endoplasmic reticulum Golgi apparatus Mitochondria Lysosomes Explanation: The cytoplasm surrounds the nucleus, and it is in the cytoplasm that the work of the cell takes place. Embedded in the cytoplasm are various membrane-enclosed organelles (e.g., endoplasmic reticulum, Golgi apparatus, mitochondria, and lysosomes) and complexes without membranes (e.g., ribosomes and proteasomes) that have important functions in cells. In addition to its organelles, the cytoplasm also contains a network of microtubules, actin microfilaments, and intermediate filaments called the cytoskeleton.
Although energy is not made in mitochondria, they are known as the "power plants" of the cell. Why are they thought of this way?
Extract energy from organic compounds Explanation: Mitochondria contain the enzymes that can change carbon-containing nutrients into energy that is easily accessible to the cell. Mitochondria contain their own DNA. Glycolysis is anaerobic metabolism and unrelated to oxidative energy. Mitochondria store phosphate bonds (such as in ATP) to power cellular functions.
A client with type 1 diabetes mellitus is experiencing hyperglycemia. Consequently, the client's cells lack intracellular glucose, resulting in glucose accumulating in the blood. Which process would best allow glucose to cross into the cell membranes? Endocytosis Secondary active transport Facilitated diffusion Simple diffusion
Facilitated diffusion Explanation: Transport molecules perform facilitated diffusion, in which one substance carries another substance across a cell membrane. Simple diffusion does not require a transport molecule. Glucose does not cross the cell membrane by secondary active transport or endocytosis.
Which statement regarding cell metabolism is most accurate? Glycolysis also provides energy in situations when delivery of oxygen to the cells is delayed. Anabolism consists of breaking down stored nutrients and body tissues to produce energy. Energy from foodstuffs is used to convert ATP to ADP. The aerobic pathway occurs in the cytoplasm.
Glycolysis also provides energy in situations when delivery of oxygen to the cells is delayed. Explanation: Glycolysis provides energy in situations when delivery of oxygen to the cells is delayed or impaired. Anabolism is a constructive process, in which more complex molecules are formed from simpler ones. Energy from foodstuffs is used to convert ADP to ATP. The aerobic pathway occurs in the mitochondria.
When working with a client who has end-stage renal disease (ESRD) and is receiving peritoneal dialysis, the concept of diffusion can be explained by which statement? "If your potassium level is high, then K+ particles will move from your peritoneal cavity into the dialysis solution, where the concentration of K+ is lower." "If you can get very warm in a sauna, you will heat up your K+ particles, and the kinetic movement of the particles will increase and pass through the cell membranes faster." "You will need to give yourself a potent diuretic so that you can pull the potassium into your bloodstream and filter the potassium out in your kidneys." "Your potassium molecules are lipid soluble and will dissolve in the lipid matrix of your cell membranes."
If your potassium level is high, then K+ particles will move from your peritoneal cavity into the dialysis solution, where the concentration of K+ is lower." Explanation: Diffusion refers to the passive process by which molecules and other particles in a solution become widely dispersed and reach a uniform concentration because of energy created by their spontaneous kinetic movements. In the process of reaching a uniform concentration, these molecules and particles move "downhill" from an area of higher to an area of lower concentration. Lipid-soluble molecules, such as oxygen, carbon dioxide, alcohol, and fatty acids (not K+) become dissolved in the lipid matrix of the cell membrane and diffuse through the membrane in the same manner that diffusion occurs in water. Diuretics are not very effective if a person has ESRD. The rate of diffusion depends on how many particles are available for diffusion, the kinetic movement of the particles, and the number and size of the openings in the membrane through which the molecules or ions can move. The environmental temperature does not play a role in this.
The nurse is educating about the importance of improving the metabolic process in a client who has morbid obesity and is beginning a weight loss program with exercise. What should the nurse inform the client about the importance of improving the metabolic rate? Increasing metabolism will improve the breakdown of carbohydrates, fats, and proteins to provide energy for cell function. Increasing metabolism will allow the client to be able to eat whatever foods he wants as long as he is exercising. Increasing metabolism improves the secretion of intracellular substances into the extracellular spaces. Increasing metabolism improves the process by which cells engulf materials from their surroundings to improve electrolyte function.
Increasing metabolism will improve the breakdown of carbohydrates, fats, and proteins to provide energy for cell function. Explanation: Metabolism is the process whereby carbohydrates, fats, and proteins from the foods we eat are broken down and subsequently converted into the energy needed for cell function.
The nucleus is called the center of the cell because it has the ability to do which of the following? It carries and copies DNA instructions for protein synthesis to the cytoplasm. It contains the DNA that is essential for protein synthesis to keep the cell alive. It breaks down and digests worn-out parts of the cell. It transforms organic compounds into energy that is accessible to the cell.
It contains the DNA that is essential for protein synthesis to keep the cell alive. Explanation: The nucleus contains the DNA that is essential to the cell because its genes contain the information necessary for the synthesis of proteins that the cell must produce to stay alive. The messenger RNA copies and carries the DNA instructions. The mitochondria transforms compounds into energy.
Which cellular organelle transforms organic compounds into energy that is easily accessible to the cell? Lysosomes Golgi complex Mitochondria Ribosomes
Mitochondria Explanation: The mitochondria are literally the "power plants" of the cell because they transform organic compounds into energy that is easily accessible to the cell. They do not make energy, but extract it from organic compounds.
A school nurse is teaching a class on immunity. Which statement contains an accurate explanation about cellular defenses? Cells release enzymes into the extracellular fluid and this degrades invading organisms. Ion channels allow rapid polarity changes, which inactivate invading organisms. Active transport draws invading organisms through cell channels to be destroyed. Neutrophils engulf invading organisms where lysosomes break them down.
Neutrophils engulf invading organisms where lysosomes break them down. Explanation: Phagocytosis is when a cell, such as macrophages or neutrophils, engulfs an invading organism or damaged cells. Once inside the cell, the encapsulated particle is broken down by lysosomal enzymes.
What are the three main parts of a typical cell? Select all that apply. Nucleus Cytoplasm Vacuole Cell membrane Cell wall
Nucleus Cell membrane Cytoplasm Explanation: When seen under a light microscope, three major components of the cell become evident: the nucleus, the cytoplasm, and the cell membrane. Cell walls and vacuoles are found in plants and bacteria.
Which statement is true concerning human cell division? Parent cell divides and each daughter cell receives chromosomes identical to the parent. Gene activity is needed for the electrical and chemical signaling systems within human cells. All cells divide with a human organism daily. Within 24 hours the organism is a morula.
Parent cell divides and each daughter cell receives chromosomes identical to the parent. Explanation: Cell division, or mitosis, is the process during which a parent cell divides and each daughter cell receives chromosomes identical to the parent. The series of mitotic divisions is called cleavage. Gene activity is needed for cell division and cell replication.
The cell membrane is also called what? Bilayer membrane Plasma membrane Nuclear membranes Receptor membrane
Plasma membrane Explanation: The cell membrane is often called the plasma membrane. The nuclear membrane is another type of membrane within the cell. The cell membrane provides receptors for hormones and other biologically active substances; it is not a receptor membrane. A main structural component of the membrane is its lipid bilayer. It is not a bilayer membrane.
The mitochondria are literally the "power plants" of the cell because they transform organic compounds into energy that is easily accessible to the cell. What do the mitochondria do? Need DNA from other sources to replicate Produce ATP from carbon sources Make energy Form proteasomes
Produce ATP from carbon sources Explanation: The mitochondria do not make energy, but they extract it from organic compounds. Proteasomes are small organelles composed of protein complexes that are thought to be present in both the cytoplasm and the nucleus. They are not formed by mitochondria. Mitochondria contain their own DNA and ribosomes and are self-replicating.
There are two forms of endoplasmic reticulum (ER) found in a cell. They are the rough and the smooth ER. What does the rough ER do in a cell? Destroys ribosomes Produces proteins Combines protein with other components of the cytoplasm Exports protein from the cell
Produces proteins Explanation: Rough ER is studded with ribosomes attached to specific binding sites on the membrane. Proteins produced by the rough ER are usually destined for incorporation into cell membranes and lysosomal enzymes or for exportation from the cell. The rough ER segregates (rather than combines) these proteins from other components of the cytoplasm and modifies their structure for a specific function. Rough ER does not transport anything through the cell membrane. Rough ER is studded with ribosomes; it does not destroy them.
The Golgi complex, or Golgi bodies, consists of stacks of thin, flattened vesicles or sacs within the cell. These Golgi bodies are found near the nucleus and function in association with the endoplasmic reticulum (ER). What is one purpose of the Golgi complex?
Receive proteins and other substances from the cell surface by a retrograde transport mechanism Explanation: Recent data suggest that the Golgi apparatus has yet another function: it can receive proteins and other substances from the cell surface by a retrograde transport mechanism. Golgi bodies do not produce bile. They produce secretory, not excretory, granules, and they produce largecarbohydrate molecules rather than small ones.
Which type of ribonucleic acid (RNA) structure translates the instructions needed for protein synthesis? Transfer RNA Polymerase RNA Messenger RNA Ribosomal RNA
Ribosomal RNA Explanation: Ribosomal RNA translates the instructions and provides the machinery needed for protein synthesis. Messenger RNA carries the instructions for protein synthesis, obtained from the DNA molecule, into the cytoplasm. Transfer RNA reads the instructions and delivers the appropriate amino acids to the ribosome. Genes are transcribed by enzymes called RNA polymerases that generate a single-stranded RNA identical in sequence (with the exception of U in place of T) to one of the strands of DNA.
Which type of epithelium is found in the lining of blood vessels, lymph nodes, and alveoli of the lungs? Transitional epithelium Pseudostratified epithelium Stratified epithelium Simple squamous epithelium
Simple squamous epithelium Explanation: Simple squamous epithelium is adapted for filtration, which works well on the blood vessels, lymph nodes, and alveoli of the lungs. Stratified squamous keratinized epithelium makes up the epidermis of the skin. A pseudostratified ciliated columnar epithelium with goblet cells forms the lining of most of the upper respiratory tract. Transitional epithelium is well adapted for the lining of organs that are constantly changing their volume, such as the urinary bladder.
What statement is true concerning the use of ATP [adenosine triphosphate] by skeletal muscles? Skeletal muscles store ATP during exercise. Skeletal muscles increase the use of ATP at rest. Skeletal muscles use ATP at a rapid rate during exercise. Skeletal muscles do not use ATP for energy.
Skeletal muscles use ATP at a rapid rate during exercise. Explanation: Skeletal muscles use minimal amounts of ATP when relaxed, and use ATP at a rapid rate when exercising.
A nurse on the oncology ward in the hospital is doing some background research to better understand the molecular basis of cancer. She comes to the understanding that transformed cancer cells are very similar to a normal type of cell, with the exception of regulation of division. Which cell type found in the normal state is most similar to a cancer cell?
Stem cells Explanation: Cancer cells and stem cells have very similar characteristics. They both are immortal and undifferentiated, unlike epithelial, muscle, and neural tissue. The primary difference between stem cells and cancer cells is the rate and regulation of division. Cancer cells have lost the ability to regulate the cell cycle.
A young, healthy adult helps lift a sofa to move it 25 feet. The nurse knows that which source of energy will the client most likely use in this process? Stored ATP Fatty acids Glucose Amino acids
Stored ATP Explanation: Stored ATP, creatine phosphate, and muscle glycogen are among the first energy sources utilized during aerobic exercise. Amino acids, fatty acids, and glucose are utilized after prolonged periods of exercise.
The student is examining a tissue sample with a microscope. The student decides that it is squamous keratinized tissue. Which type of epithelial tissue is the student viewing? Neuroepithelium Stratified epithelium Glandular Simple epithelium
Stratified epithelium Explanation: Stratified, squamous keratinized epithelium makes up the epidermis of the skin. Simple epithelium is found in the lining of blood vessels, lymph nodes, and alveoli of the lungs. Glandular epithelium is located in exocrine and endocrine glands. Neuroepithelium is located in in olfactory mucosa, retina, and the tongue.
Ultimately, the inner mitochondrial membrane transports proteins for what purpose?
Synthesis of adenosine triphosphate (ATP) Explanation: The outer mitochondrial membrane contains a large number of transmembrane porins, through which water-soluble molecules may pass. The inner membrane contains the respiratory chain enzymes and transport proteins needed for the synthesis of ATP. The mitochondrial membrane does not play a role in cell repair or growth.
Which body tissue exhibits the highest rate of turnover and renewal? The skeletal muscle that facilitates movement The connective tissue supporting blood vessels The nervous tissue that constitutes the central nervous system The epithelial cells of the skin
The epithelial cells of the skin Explanation: Cells making up the epithelial tissues generally undergo rapid proliferation for replacing injured cells, which is related to their location and function. Renewal of connective and muscle tissue takes place at a much slower pace, whereas nervous tissue is incapable of postnatal regeneration.
Each skeletal muscle is a discrete organ made up of hundreds or thousands of muscle fibers. Although muscle fibers predominate, substantial amounts of connective tissue, blood vessels, and nerve fibers are also present. What happens during muscle contraction? The thick myosin and thin actin filaments slide over each other, causing shortening of the muscle fiber. Calcium-calmodulin complexes produce the sliding of the filaments that form cross-bridges with the thin actin filaments. During contraction, each cross-bridge undergoes its own cycle of movement, forming a bridge attachment and releasing it; the same sequence of movement repeats itself when the cross-bridge reattaches to the same cell. When activated by GTP (guanosine 5′-triphosphate), the cross-bridges swivel in a fixed arc, much like the oars of a boat, as they become attached to the actin filament.
The thick myosin and thin actin filaments slide over each other, causing shortening of the muscle fiber. Explanation: Thin and thick filaments are the two types of muscle fibers that are responsible for muscle contraction. The thin filaments are composed primarily of actin, and the thick filaments are composed of myosin. During muscle contraction, the thick myosin and thin actin filaments slide over each other, causing shortening of the muscle fiber, although the length of the individual thick and thin filaments remains unchanged. When activated by ATP, the cross-bridges swivel in a fixed arc, much like the oars of a boat, as they become attached to the actin filament. During contraction, each cross-bridge undergoes its own cycle of movement, forming a bridge attachment and releasing it, and moving to another site where the same sequence of movement occurs. This pulls the thin and thick filaments past each other. The calcium-calmodulin complex is in smooth muscle. It binds to and activates the myosin-containing thick filaments, which interact with actin.
Which role does adipose tissue play in the body? Make collagen Balance electrolytes Thermal insulation Manufacture energy
Thermal insulation Explanation: Adipose tissue stores triglycerides, which act as energy reserves. It also insulates the body from heat loss, and supports organs and structures. Collagen is made by connective tissue called fibroblasts. Energy is produced in the mitochondria. Electrolyte balance is regulated by the renal system and the cell ion channels.
Which explanation identifies correctly how the G protein-linked receptors are similar? Their cytosolic domain has intrinsic enzyme activity. These linked receptors are involved in rapid synaptic signaling between cardiac electrical cells. They have a ligand-binding extracellular receptor component, which causes changes that activate the G protein on the cytoplasmic side of the cell membrane. Insulin is an example of the second messenger cyclic AMP (cAMP), which binds to an enzyme-linked receptor.
They have a ligand-binding extracellular receptor component, which causes changes that activate the G protein on the cytoplasmic side of the cell membrane. Explanation: Although there are differences among the G protein-linked receptors, all share a number of features. They all have a ligand-binding extracellular receptor component, which recognizes a specific ligand or first messenger. Upon ligand binding, they all undergo conformational changes that activate the G protein found on the cytoplasmic side of the cell membrane. Instead of having a cytosolic domain that associates with a G protein, enzyme-linked receptors have cytosolic domain either that has intrinsic enzyme activity or that associates directly with an enzyme. The binding of the hormone to a special transmembrane receptor results in activation of the enzyme adenylyl cyclase at the intracellular portion of the receptor. This enzyme then catalyzes the formation of the second messenger cAMP, which has multiple effects on cell function. Insulin, for example, acts by binding to an enzyme-linked receptor. Ion channel-linked receptors are involved in the rapid synaptic signaling between electrically excitable cells.
How does facilitated diffusion enable molecules to cross cell membranes? Substances use energy to move against the concentration gradient. Ion channels are triggered to open and molecules cross the membrane. Transport proteins carry molecules to areas of lower concentration. Molecules are pulled in the direction of less concentration.
Transport proteins carry molecules to areas of lower concentration. Explanation: Diffusion is movement of a substance across cell membranes in the direction of a lower concentration. Facilitated diffusion also moves substances to areas of lower concentration, but with the assistance of a carrier molecule. Ion channels are proteins that allow certain electrolyte ions to pass rapidly through the membrane. Active transport occurs when a transport protein carries substances across the cell membrane toward an area of higher concentration.
Smooth muscle contractions are typically characterized as: voluntary. involuntary. somatic. motor based.
involuntary. Explanation: Smooth muscle is often called involuntary muscle because it contracts without the person willing it to contract. Voluntary, motor, and somatic contractions are all under conscious control.
Although the majority of cellular DNA exists in the cell nucleus, the part of the cell DNA from one's mother is located where? smooth endoplasmic reticulum mitochondria Golgi apparatus microfilaments
mitochondria Explanation: In addition to nuclear DNA, part of the DNA of a cell resides in the mitochondria. Mitochondrial DNA (mtDNA) is inherited from the mother by her offspring. DNA is not present in the Golgi apparatus, smooth endoplasmic reticulum, or microfilaments.
While reviewing the basic information related to hemodialysis, the professor explains that water molecules move through adjacent phospholipid molecules in the cell membrane by: secondary active transport. diffusion. active transport. vesicular transport. osmosis.
osmosis. Explanation: Water molecules move through adjacent phospholipid molecules in the cell membrane by osmosis without actually dissolving in the region occupied by the fatty acid side of the chains. Osmosis is regulated by the concentration of nondiffusible particles on either side of the membrane, with water moving from the side with the lower concentration of particles to the side with the higher concentration.
The organelle responsible for synthesis of proteins by bound ribosomes is called:
rough endoplasmic reticulum. Explanation: The rough endoplasmic reticulum contains bound ribosomes that are responsible for manufacturing proteins such as pancreatic enzymes and plasma proteins.
The majority of the cell's protoplasm is: lipids. electrolytes. proteins. water.
water. Explanation: Water makes up 70% to 85% of the cell's protoplasm. The second most abundant constituents (10% to 20%) of the protoplasm are the cell proteins.