Cells Flashcards
Which term is assigned to the study of cellular structure and function?
Cytology
What is the structural and functional unit of all living matter that vary considerably in size, shape, and function?
Cell
Which unit of living matter’s structure and function are closely related?
Cell
Plasma Membrane
Cell Membrane
What encases the cell?
Cell Membrane
Which cell component separates intracellular (inside the cell) material from extracellular (outside of the cell) material?
Cell Membrane
Which cell component physically holds the cell together?
Cell Membrane
Which cell component’s chief function is the selection of substances allowed to enter or leave the cell?
Cell Membrane
Because the membrane chooses the substances allowed to cross it, the membrane is said to be selectively ___, or semi___.
permeable x 2
What three components compose a cell membrane?
Phospholipids
Protein
Carbohydrates
Which cell membrane component is arranged in two layers?
Phospholipids
What performs several important functions in the cell membrane like providing structural support, acting as binding sites for hormones, and poking holes, or pores, through the lipid membrane (pores form channels through which water and dissolved substances flow)?
Protein
Substances move across the semipermeable membrane in two ways.
They can dissolve in the ___ portion of the membrane, as do oxygen and carbon dioxide (___-soluble substances).
Substances can also cross the membrane by flowing through the ___.
lipid x 2
pores
What are water and electrically charged substances such as sodium and chloride that can not penetrate the lipid membrane and must use the pores considered?
Water-Soluble
Which aspect of the pores helps select which substances cross the membrane?
Size
Substances larger than the pores cannot cross the membrane, whereas smaller substances such as sodium and chloride flow through easily.
Which two categories determine how drugs are classified?
Lipid-Soluble
Water-Soluble
What determines drug distribution throughout the body?
Solubility
Which two compartments is the cell’s inside divided into?
Nucleus
Cytoplasm
The inside of the cell resembles the inside of a raw egg; the “yellow yolk” is the ___, and the “white” is the ___.
nucleus
cytoplasm
Which compartment is the control center of the cell?
Nucleus
Which cell compartment contains the genetic information and controls all protein synthesis?
Nucleus
How many nucleuses do most adult cells have?
One
Only mature red blood cells (RBC) have no nucleus.
What is double-layered and surrounds the nucleus?
Nuclear Membrane
What contains large pores that allow the free movement of certain substances between the nucleus and cytoplasm?
Nuclear Membrane
What fluid filled substance is the nucleus filled with?
Nucleoplasm
Which two structures are within the nucleoplasm?
Nucleolus
Chromatin
“Little Nucleus”
Nucleolus
What synthesizes the ribosomes that move through nuclear pores into the cytoplasm, where they play a role in protein synthesis?
Nucleolus
What is composed mainly of strands of DNA (deoxyribonucleic acid), the carriers of the genetic code?
Chromatin
What are the tangled array of fine filaments in nondividing cells?
Chromatin
What are the DNA-containing structures formed by chromatin strands that coil tightly in dividing cells?
Chromosomes
“Gel in the Cell”
Cytoplasm
What is found inside the cell but outside the nucleus (like the white of a raw egg)?
Cytoplasm
Which two components does the cytoplasm contain?
Cytosol
Organelles
What is the intracellular fluid composed primarily of water, electrolytes, proteins, and nutrients?
Cytosol
Which cell component contains inclusion bodies, insoluble materials such as glycogen granules, and pigments such as melanin?
Cytosol
“Little Organs”
Organelles
What is dispersed throughout the cytoplasm; each having a specific role?
Organelles
Which term is assigned to the tiny, slipper-shaped organelles?
Mitochondria
Which cell component’s number varies depending on the metabolic activity of the cell (how hard the cell works)?
Mitochondria
The more metabolically active the cell, the greater the number of mitochondria.
Which cell component is present in larger numbers in the liver because the liver cells are very active?
Mitochondria
Which cell component is present in fewer numbers in bone because bone cells are less metabolically active?
Mitochondria
The mitochondrial membrane has two layers; the outer layer is smooth, whereas the inner layer has many folds, referred to as ___.
cristae
Where are the enzymes associated with adenosine triphosphate (ATP) production located along?
Cristae
Which component is referred to as the “power plants” of the cell because they produce most of the energy [adenosine triphosphate (ATP)] in the body?
Mitochondria
What are the cytoplasmic organelles involved in protein synthesis?
Ribosomes
Which cell component is attached to the endoplasmic reticulum?
Fixed Ribosome
Which cell component is largely concerned with the synthesis of exportable protein - that is, protein secreted by the cell for use elsewhere in the body?
Fixed Ribosome
Which cell components float freely within the cytoplasm and generally synthesize proteins that are used within the cell?
Free Ribosomes
What is the network of membranes within the cytoplasm?
Endoplasmic Reticulum (ER)
What are the long, folded membranes that form channels through which substances, especially newly synthesized protein, move?
Endoplasmic Reticulum (ER)
What are the two types of endoplasmic reticulum (ER)?
Rough Endoplasmic Reticulum (RER)
Smooth Endoplasmic Reticulum (SER)
Which endoplasmic reticulum (ER) type contains ribosomes along its surface?
Rough Endoplasmic Reticulum (RER)
The rough endoplasmic reticulum (RER) has a sandpaper-like appearance.
Which endoplasmic reticulum (ER) type is primarily concerned with protein synthesis?
Rough Endoplasmic Reticulum (RER)
Where is the protein that is synthesized along the rough endoplasmic reticulum (RER) and transported through the channels delivered to for further processing?
Golgi Apparatus
Which endoplasmic reticulum (ER) type does not contain ribosomes on its surface?
Smooth Endoplasmic Reticulum (SER)
Which endoplasmic reticulum (ER) type is primarily involved in the synthesis of lipids, steroids, glycerides, and glycogen in skeletal muscle and liver cells?
Smooth Endoplasmic Reticulum (SER)
Which cell component is a series of flattened membranous sacs?
Golgi Apparatus
Which cell component forms the channels through which synthesized protein is transported to the Golgi apparatus?
Endoplasmic Reticulum (ER)
Which cell component puts the finishing touches on the protein?
Golgi Apparatus
A glucose molecule may be attached to a protein within the golgi apparatus. A segment of the golgi membrane then wraps itself around the protein and pinches itself off to form a ___ ___. In this way, the Golgi apparatus packages the protein.
secretory vesicle
Which three organelles are involved in protein synthesis?
Ribosomes
Endoplasmic Reticulum (ER)
Golgi Apparatus
What are the membranous sacs containing powerful enzymes?
Lysosomes
Which cell component’s enzymes break down intracellular waste and debris, including damaged organelles, and thus help “clean house?”
Lysosomes
Which cell component’s enzymes kill ingested bacteria?
Lysosomes
Which cell component breaks down the contractile proteins of inactive muscles, as occurs in retired athletes and chronically bedridden persons?
Lysosomes
What are the two threadlike structures that compose the cytoskeleton?
Microfilaments
Microtubule
Which cell component helps maintain the shape of the cell and assists the cell in various forms of cellular movement?
Cytoskeleton
What do muscle cells contain in large numbers, allowing cellular movement?
Microfilaments
What is the primary component of the cytoskeleton?
Microtubule
Which cell component makes the cell strong and rigid, anchoring the position of the organelles within the cytoplasm?
Microtubules
Which cell component plays a key role in cell division; they form the spindle apparatus that helps distribute the chromosomes to opposite ends of the dividing cell?
Microtubules
What are the paired, rod-shaped, and short microtubular structures that form the spindle apparatus in a dividing cell?
Centrioles
What do cells lack to be incapable of cell division; these include neurons, mature red blood cells (RBC), skeletal muscle cells, and cardiac muscle cells?
Centrioles
What are the accordion-like folds the membrane forms when cells are particularly involved with the movement of large amounts of water and its dissolved solutes?
Microvilli
The folding of the cell membrane increases surface area, thereby increasing the amount of fluid absorbed.
What do the cells in the digestive tract have millions of to absorb water and the end products of digested food?
Microvilli
What are the short, hairlike projections on the outer surface of the cell membrane?
Cilila
Which cell component uses wavelike motions to move substances across the surface of the cell?
Cilia
Which cell component is abundant in the cells that line the respiratoy passages, helping move the mucus and trapped dust and dirt toward the throat, away from the lungs?
Cilia
Which cell component is damaged by cigarettes thus depriving the smoker of its benefit?
Cilia
“Whiplike”
Flagella
Which cell component is similar to cilia in that both are hairlike projections of the cell membrane?
Flagella
Which cell component is thicker, longer, and fewer in number; and help move the cell?
Flagella
What is the tail of the sperm that enables it to swim?
Flagella
A Typical Cell
Functions of the Cellular Components
Structure of the Cell Membrane Bilayer
“Power Plants” of the Cell - Adenosine Triphosphate (ATP)
The Golgi Apparatus: Packages the Protein for Export
Cells are bathed in an extracellular fluid that is rich in nutrients such as oxygen, glucose, and amino acids. These nutrients are needed in the cell and must therefore be able to cross the cell membrane. The cell’s waste, which accumulates within the cell, must also be able to cross the cell membrane for eventual elimination.
A number of mechanisms assist in the movement of water and dissolved substances across the cell membrane. The transport mechanisms can be divided into two groups: ___ transport and ___ transport mechanisms.
passive
active
Which transport mechanisms require no additional input of energy in the form of adenosine triphosphate (ATP)?
Passive
Which type of transport mechanisms are something like the downward movement of a ball?
Passive
Which transport mechanisms cause water and dissolved substances to move without additional energy?
Passive
Which type of transport mechanisms require an input of energy in the form of adenosine triphosphate (ATP)?
Active
Which transport mechanism is like the upward movement of a ball?
Active
For the ball to move uphill, it must be pushed, therefore requiring an input of energy.
What are the four passive mechanisms that move substances across the membrane?
Osmosis
Diffusion
Filtration
Facilitated
Which transport mechanism is the most common?
Diffusion
Which transport mechanism occurs when a substance moves from an area of higher concentration to an area of lower concentration?
Diffusion
Which transport mechanism occurs when a tablet of red dye is placed in a glass of water, the tablet dissolves, and the dye moves from an area where it is most concentrated to an area where it is less concentrated?
Diffusion
Diffusion continues until the dye is evenly distributed throughout the glass.
What is the point at which no further net diffusion occurs?
Equilibrium
Which transport mechanism occurs when perfume’s scent permeates an area?
Diffusion
Which transport mechanism occurs when oxygen moves across the membrane of an alveolus of the lung into the blood?
Diffusion
Oxygen diffuses from the alveolus because the concentration of oxygen is higher within the alveolus than within the blood. Conversely, carbon dioxide, a waste product that accumulates within the blood, diffuses in the opposite direction (carbon dioxide moves from the blood into the alveolus). The lungs then exhale it, thereby eliminating waste from the body. Thus the process of diffusion moves oxygen into the blood and carbon dioxide out of the blood.
Diffusion
Which transport mechanism is a form of diffusion that is responsible for the transport of many substances?
Facilitated
Facilitate means “to help”.
Which transport mechanism occurs when substances move from a higher concentration toward a lower concentration; however, the substance is helped across the membrane by a molecule within the membrane?
Facilitated
The helper molecule increases the rate of diffusion.
Facilitated
Which transport mechanism is the diffusion of water through a selectively permeable membrane?
Osmosis
Which transport mechanism occurs when water diffuses from an area with more water to one with less (the dissolved substances, however, do not move)?
Osmosis
Two different solutions in the glass illustrate ___. The glass is divided into two compartments (A and B) by a semipermeable membrane. Compartment A contains a dilute glucose solution, whereas compartment B contains a more concentrated glucose solution. The membrane is permeable only to water. The glucose cannot cross the membrane and is therefore confined to its compartment. During ___, the water moves from compartment A to compartment B (from the area where there is more water to the area with less). The following two effects occur: (1) the amount, or volume, of water in compartment B becomes greater than the volume in compartment A; and (2) the concentrations of the solutions in both compartments change. The solution in compartment A becomes more concentrated, whereas the solution in compartment B becomes more dilute.
Because water moves toward the more concentrated solution, it appears to be “pulled” in that direction.
osmosis x 2
Which transport mechanism is sometimes described as a “pulling” pressure?
Osmosis
Which transport mechanism occurs when Na+ pulls or holds water?
Osmosis
More correctly stated, water diffuses into the more concentrated saline solution.
Which transport mechanism causes water to move into a compartment and can therefore cause swelling?
Osmosis
Which transport mechanism is responsible for water diffusing toward the protein, causing the tissues to swell (edema)?
Osmosis
Tissue injury causes leakage and accumulation of proteins within the tissue space. The confined proteins act osmotically.
What is the ability of a solution concentration to affect the volume and pressure within a cell?
Tonicity
Which three terms are used to illustrate tonicity?
Isotonic
Hypotonic
Hypertonic
Which tonic solution has the same concentration as intracellular fluid?
Isotonic
Iso means “same”.
Which sort of solution would a red blood cell (RBC) have to be placed in for no net movement of water to occur (the cell neither gains nor loses water)?
Isotonic
If a red blood cell (RBC) is placed in pure water (a solution containing no solute), then water moves into the cell by ___ (from where there is more water to where there is less water). The pure water, being more dilute than the inside of the cell, is said to be ___.
osmosis
hypotonic
Which solutions cause red blood cells (RBC) to burst, or lyse, in a process referred to as hemolysis?
Hypotonic
What would occur if pure water were administered intravenously?
Hemolysis
If a red blood cell (RBC) is placed within a very concentrated salt solution, water diffuses out of the red blood cell (RBC) into the bathing solution, causing the red blood cell (RBC) to shrink, or ___. The salt solution is referred to as a ___ solution.
crenate
hypertonic
Why is the tonicity of a solution important?
If the cell gains water, the red blood cell (RBC) membrane ___. If the red blood cell (RBC) loses water, the cell ___. In both cases, red blood cell (RBC) function is impaired.
bursts
Which tonic solutions do not cause cells to swell or shrink?
Isotonic
Which tonic solution is clinically and frequently administered intravenously?
Isotonic
Commonly used isotonic solutions include normal saline (0.9% NaCl), 5% D/W (5% dextrose or glucose in water, or D5W), and Ringer solution. Under special conditions, hypotonic or hypertonic solutions may be administered intravenously
Tonicity
With ___ and ___, water and dissolved substances move across the membrane in response to a difference in concentrations.
diffusion
osmosis
Which transport mechanism exists when water and dissolved substances cross the membrane in response to differences in pressures?
Filtration
In other words, pressure pushes substances across the membrane.
Which transport mechanism does a syringe illustrate?
Filtration
A) Water is forced through the needle.
B) Water (H2O) is forced through the holes in the barrel of the syringe.
C) Water is forced out of the capillary through holes, or pores.
Filtration
Which transport type refers to a transport mechanism that requires an input of energy adenosine triphosphate (ATP) to achieve its goal?
Active
Which transport mechanism type is necessary to pump certain substances because the amount of some substances in the cell is already so great that the only way to move additional substances into the cell is to pump them in?
Active
Which transport mechanism type is necessary because a cell normally contains a large amount of potassium ions (K+) and the only way to move additional K+ into the cell is to pump it in?
Active
Which transport mechanism involves the intake of food or liquid by the cell membrane?
Endocytosis
Which transport mechanism occurs when the particle is too large to move across the membrane by diffusion; instead, the particle is surrounded by the cell membrane, which engulfs it and takes it into the cell?
Endocytosis
Which two forms of endocytosis exist?
Phagocytosis
Pinocytosis
Which form of endocytosis involves a solid particle?
Phagocytosis
“Eating”.
Phago
Which form of endocytosis exists when white blood cells eat bacteria, thereby helping the body defend itself against infection?
Phagocytosis
Which form of endocytosis exists when the cell ingests a water droplet?
Pinocytosis
“Cellular drinking”.
Pinocytosis
Which transport mechanism moves substances out of the cells?
Exocytosis
Which transport mechanism is described below?
The cells of the pancreas make proteins for use outside the pancreas. The pancreatic cells synthesize the protein and wrap it in a membrane. This membrane-bound vesicle moves toward and fuses with the cell membrane. The protein is then expelled from the vesicle into the surrounding space.
Exocytosis
What is necessary for the body’s growth, repair, and reproduction?
Cell Division
Some cells reproduce very frequently, whereas other cells reproduce very slowly or not at all. For example, the cells that line the digestive tract are replaced every few days, and more than 2 million RBCs are replaced every second. Certain nerve cells in the brain and spinal cord, however, do not reproduce at all.
Which two types of cell division exist?
Meiosis
Mitosis
Which type of cell division occurs only in sex cells?
Meiosis
Which cell division type is involved in bodily growth and repair?
Mitosis
Which cell divsion type is the splitting of one mother cell into two identical “daughter cells?”
Mitosis
The key word is identical.
Which cell division type occurs when an exact copy of genetic information, stored within the chromosomes, is passed from the mother cell to the two daughter cells?
Mitosis
What is the sequence of events that the cell goes through from one mitotic division to the next?
Cell Cycle
Which two major phases is the cell cycle divided into?
Interphase
Mitosis
Which phase occurs when the cell carries on with its normal functions and gets ready for mitosis through growth and DNA replication?
Interphase
Which three phases is interphase divided into?
First Gap Phase (G1)
Phase (S)
Second Gap Phase (G2)
Which interphase phase occurs when the cell carries on its normal activities and begins to make the DNA and other substances necessary for cell division?
First Gap Phase (G1)
Which interphase phase occurs when the cell duplicates its chromosomes, thereby making enough DNA for two identical cells?
Phase (S)
Which interphase phase includes the synthesis of enzymes and other proteins needed for mitosis?
Second Gap Phase (G2)
Which phase does the cell enter at the end of second gap phase (G2)?
Mitotic (M)
Which phase occurs when the cell divides into two cells in such a way that the nuclei of both cells contain identical genetic information?
Mitotic (M)
What are the four phases of mitosis?
Prophase
Metaphase
Anaphase
Telophase
During ___, the chromosomes coil so tightly that they become visible under a light microscope.
Each chromosome pair is composed of two identical strands of DNA called ___; each ___ is attached at a point called the centromere.
At the same time, two pairs of ___ move to opposite poles of the nucleus.
prophase
chromatids
chromatid
centrioles
Which mitotic (M) phase includes the nuclear membrane disappearing late in its occurrence?
Prophase
Which mitotic (M) phase occurs when the chromatids are aligned in a narrow central zone (spindle fibers connect the chromatids and centrioles)?
Metaphase
Which mitotic (M) phase begins when the centromere splits and the chromatids are pulled to opposite poles at its end?
Anaphase
Which mitotic (M) phase occurs when each new cell reverts to the interphase state; the nuclear membrane reforms, the chromosomes uncoil, and the chromatin strands reappear?
Telophase
___ and ___ mark the end of mitosis (M).
Telophase
cytokinesis
What is the pinching of the cell membrane to split the cytoplasm into two distinct cells?
Cytokinesis
Cytokinesis begins in late ___.
anaphase
At the end of mitosis, the daughter cells have two choices. They can enter ___ ___ ___ (___) and repeat the cycle (and divide again) or they can enter another phase, called G ___ (G___).
first gap phase (G1)
G zero (G0)
Which phase do cells enter to “drop out” of the cell cycle and rest (do not undergo mitosis)?
G Zero (G0)
Cells may re-enter the cell cycle after days, weeks, or years. The inability to stop cycling and enter _ _ (_) is characteristic of cancer cells.
Cancer cells constantly divide and proliferate.
Anticancer drugs are more active against cells that are cycling than against cells resting in _ _ (_) . Thus tumors that contain many cycling cells respond best to chemotherapy.
G Zero (G0)
Some anticancer drugs are classified according to the cell cycle phases that they affect and are called cell cycle phase–___.
specific
Which drugs affect the cell when it is in a particular phase?
Cell Phase-Specific
With the use of this terminology, the anticancer drug methotrexate is considered cell cycle S phase–specific. Other drugs are cell cycle M phase–specific and cell cycle G2 phase–specific. Some anticancer drugs can act at any phase of the cell cycle and are called cell cycle phase–nonspecific. By knowing the cell cycle terminology, you can understand anticancer drugs better.
Cell Cycle
Stages of Mitosis
___ assures us that the division of one cell produces two identical cells.
How do we account for the differences in cells such as muscle cells, RBCs, and bone cells?
An embryo begins life as a single cell, the fertilized ovum. Through ___, the single cell divides many times into identical cells.
Then, at some time during their development, the cells start to specialize or ___.
Mitosis
mitosis
differentiate
What explains the ability cells have to switch on enzymes that produce red blood cells (RBC) or to produce bone cells?
Differentiate
What explains the phenomenon that humans start life as a single adorable cell and ended up as billions of specialized cells?
Differentiate
What does it mean when a tissue biopsy (surgical removal of tissue for examination) shows many poorly ___ cells?
It means that the tissue cells have failed to ___ or specialize.
differentiated
differentiate
Failure to ___ is characteristic of cancer cells.
differentiate
In other words, the poorly differentiated cells of a liver tumor do not resemble normal liver cells.
Which cells are relatively undifferentiated or unspecialized with the exlcusive function to produce additional unspecialized cells?
Stem
Each time a ___ cell divides, one of its daughter cells differentiates while the other daughter cell prepares for further ___ cell division.
stem x 2
Which cell’s division rate varies with the tissue type; its cells within the bone marrow and skin are capable of dividing more than once a day, whereas its cells in adult cartilage may remain inactive for years?
Stem
Which cell’s research is of particular interest in regard to its possibility of replacing damaged tissue and growing new organs?
Stem
Another advance in stem cell research is the development of a new technique that coaxes adult cells to regress to an embryonic state. These undifferentiated cells are called induced pluripotent stem cells (iPS cells). The iPS cells can then be induced to specialize into the desired cell type, such as bone, muscle, or blood cells. A major hurdle in stem cell research has been the use of embryos as stem cell donors. This technique required the destruction of the embryo, thereby creating an ethical dilemma for many. The development of iPS cells eliminates this issue and hopefully will hasten stem cell research.
What exists when cell growth becomes uncontrolled and disorganized, and too many cells are produced?
Tumour
Tumour means “swelling”.
Which two ways are tumors classified?
Benign (noncancerous)
Malignant (cancerous)
Cancer cells are appropriately named. Cancer means “crab”; cancer cells, like a crab, send out clawlike extensions that invade surrounding tissue.
Cancer cells also detach from the original tumor (___ site) and spread throughout the body (___ sites).
Widespread invasion of the body by cancer cells often causes death. The spreading of cancer cells is referred to as ___ .
primary
secondary
metastasis
||Tumour = Neoplasm
What is a diagnostic procedure used to detect cancer?
Smear
What is a sample of cells?
Smear
What is the programmed sequence of events that leads to cell death?
Apoptosis
Cell Suicide
What helps rid the body of old, unnecessary, and unhealthy cells?
Apoptosis
What is necessary in the elimination of some cells because the body replaces a million cells per second?
Apoptosis
What can sometimes go into overdrive, causing excessive cellular death and disease?
Apoptosis
What are cells that are sometimes injured so severely they die?
Necrose
From the Greek word necros, meaning “death”.
What occurs when cells are deprived of oxygen for too long a period, poisoned, damaged by bacterial toxins, or suffer the damaging effects of radiation?
Necrose
What is an adaptive process that results in a decrease in the size of a tissue or organ caused by a decrease in the number of cells or a reduction in cell size?
Atrophy
What is diminished blood supply, muscle inactivity, nutritional deficiency, and the natural aging process?
Muscular Dystrophy
What is an increase in the size (not number) of cells; a response to increased workload?
Hypertrophy
Lifting weights hypertrophies arm and shoulder muscles.
What is an increase in the number of cells caused by an increase in cell division?
Hyperplasia
There is compensatory and hormonal hyperplasia.
What is a reversible cellular transformation (from one cell type to another)?
Metaplasia
Cigarette smoking can cause the transformation of columnar epithelium into squamous epithelium; cessation of smoking can reverse the cellular change.
What cell growth includes cells that are poorly differentiated (immature and embryonic) and characteristic of malignant (cancerous) cells?
Anaplasia
What is a maladaptive cellular disorder in which the cells show evidence of abnormal differentiation, resulting in changes in cell size, shape, and appearance (a malignant precursors)?
Dysplasia
Mal = bad
