Term
|
Definition
| Fluid outside the cell (outside the plasma membrane). Includes Interstitial fluid and blood plasma. |
|
|
Term
|
Definition
| Fluid found between cells, though not inside blood vessels. |
|
|
Term
|
Definition
| Membrane that separates stuff inside the cell from stuff outside the cell. |
|
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Term
|
Definition
| General term for material Plasma membrane and the nucleus of cell. |
|
|
Term
| What are the two major component groups of Cytoplasm? |
|
Definition
|
|
Term
|
Definition
| Fluid component of Cytoplasm (Intracellular fluid). |
|
|
Term
|
Definition
| "Little Organs" intracellular structures with specific functions. |
|
|
Term
| Describe the two classes of organelles: |
|
Definition
| Nonmembranous and membranous. |
|
|
Term
| Name the Nonmebranous Organelles: |
|
Definition
| Cytoskeleton, Microvilli, Centrioles, Cilia, Ribosomes. |
|
|
Term
| Name the Membranous Organelles: |
|
Definition
| Mitochondria, Nucleous, Endoplasmic Reticulum (ER), Golgi Apparatus, Lysosomes, Peroxisomes. |
|
|
Term
|
Definition
| Breakdown organic chemicals, neutralize toxic compounds generated in this process (Reactive Oxygen Species - specifically hydrogen peroxide). May be important in cholesterol creation. |
|
|
Term
|
Definition
| Breakdown of organic compounds, damaged organelles, and pathogens. |
|
|
Term
|
Definition
| Increase surface area to facilitate absorption of extracellular materials. |
|
|
Term
| Golgi Apparatus functions: |
|
Definition
| Storage, alteration, and packaging of synthesized products. |
|
|
Term
|
Definition
| Control of metabolism, storage/processing of genetic info., controls protein synthesis. |
|
|
Term
| Endoplasmic reticulum (ER) functions: |
|
Definition
| This widely disseminated organelle provides for transport within the cell, as well as the synthesis of secretory products (proteins, lipids and carbohydrates.) |
|
|
Term
| What products come from the smooth ER? |
|
Definition
| lipids and carbohydrates. |
|
|
Term
| What products come from the rough ER? |
|
Definition
| The ribosomes covering the Rough ER synthesize proteins. |
|
|
Term
|
Definition
| Protein synthesis. Target of Ricin poison. |
|
|
Term
|
Definition
| Strengthen and support the cell. Move cellular structures and materials. |
|
|
Term
|
Definition
| Cellular powerhouse where 95% of ATP. Site of Oxidative phosphorylation. Target of cyanide poison. |
|
|
Term
| Glycocalyx location and functions: |
|
Definition
| Superficial exterior of plasma membrane. These carbohydrate containing molecules are important in cell recognition, binding to extracellular structures, and lubrication of the cell surface. |
|
|
Term
| Integral Protein location and functions: |
|
Definition
| Also known as transmembrane proteins, these span the depth of the cell membrane and create machinery to allow selective movement of molecules into and out of the cell. |
|
|
Term
| Explain the structure and importance of the phospholipid bilayer. |
|
Definition
| Composed of two layers of phospholipid molecules with the hydrophilic heads towards the interior and exterior surfaces of the plasma membrane, the hydrophobic layer in the middle provides an effective barrier to separate the interior and exterior of the cell. Sugars and proteins are forced to use transmembrane proteins to enter or leave the cell. |
|
|
Term
| Peripheral proteins: location and function: |
|
Definition
| These proteins, locate on the inside or outside of the plasma membrane, are not integral to it, and their removal will not disrupt the integrity of the membrane. They have regulatory and enzymatic functions. |
|
|
Term
|
Definition
| Membrane protein: Stabilizes plasma membrane by attaching (anchoring) it to the cytoskeleton and other internal structures. |
|
|
Term
|
Definition
| Membrane protein: Used by immune system to tell self from other cells. May be integral or peripheral. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Membrane protein: binds to specific extracellular molecules (ligands). Binding can then go on to create a biological response. Ligand examples: epinephrine, Ca++. Also target of many medications. |
|
|
Term
|
Definition
| Membrane protein: Binds and transports solutes across cell membrane. |
|
|
Term
|
Definition
| Membrane protein, integral: Opens and closes to permit/restrict passage of solutes/ions across membrane. |
|
|
Term
| Microfilaments: Location in cell, size, protein composition. |
|
Definition
| Located mostly in periphery of cell. Scarce in center around nucleous. Usually < 6nm in diameter. Made of protein Actin. |
|
|
Term
|
Definition
| Found just inside the plasma membrane under microvilli. Microfilaments in the microvilli are anchored to the Terminal Web. The terminal web contains contractile fibers, which allow the cell to spread the microvilli apart, increasing surface area and absorption rate. |
|
|
Term
|
Definition
| 7-11 nm in diameter...strongest, most durable cytoskeletal elements. |
|
|
Term
|
Definition
| Approx. 25nm in diameter, these extend from a region near the nucleus (the centrosome) to the periphery of the cell. |
|
|
Term
|
Definition
| Cylindrical structures composed of short microtubules. The ring structure is composed of nine groups of three microtubules. There are two centrioles in the centrosome. The centrioles are associated with movement of DNA strands during cell division. IF A CELL LACKS CENTRIOLES, IT CAN'T DIVIDE (e.g. RBC's and skeletal muscle) |
|
|
Term
|
Definition
| Anchor for microtubules. Regulates cell-division cycle. |
|
|
Term
|
Definition
Long, slender extensions of the plasma membrane. Found in respiratory and reproductive tract, in particular. Underlying protein structure is similar to cenrioles, except with paired groups of microtubules, rather than triplicate. Additionally, there are to microtubules in the core.
|
|
|
Term
|
Definition
| The end of the centriole, and origin of the cilia. The cilia is anchored to the centriole and grows from the basal body. |
|
|
Term
| What is the ribosome comprised of? |
|
Definition
| Two sub-units, the small ribosomal subunit and the large ribosomal subunit. |
|
|
Term
| What membranous structure is the ER connected to? |
|
Definition
| The nuclear envelope of the nucleus. |
|
|
Term
| What are the chambers in the ER called? |
|
Definition
|
|
Term
| Describe the difference between the cisternae in the rough ER vs. the smooth ER: |
|
Definition
| The cisternae in the rough ER are flattened, while those in the smooth ER are round/tubular. |
|
|
Term
| Describe the principle functions of the smooth ER in detail: |
|
Definition
- Synthesis of phospholipids for all of the different membranes in the cell, including plasma, nucleus, Golgi, and ER.
- Synthesis of steroid hormones in reproductive cells.
- Synthesis/storage of glycerides in liver and fat cells.
- Synthesis/storage of glycogen in skeletal muscles/liver. |
|
|
Term
| Describe the generalized steps of protein creation and packaging in the rough ER. |
|
Definition
1. Polypeptide synthesis from ribosome. The chain enters the cisterna of the rough ER.
2. Secondary and tertiary folding of polypeptide.
3. Completion of protein/optional addition of carbohydrates to create glycoproteins.
4. Packaging of glycoproteins/protein/enzymes in Transport Vesicles.
5. Delivery of these molecules to the Golgi apparatus via Transport Vesicles. |
|
|
Term
| What is the percentage of smooth ER vs. rough ER in the cells. |
|
Definition
| It depends on the cell's need to produce proteins, especially enzymes. Organs, such as the pancreas which create large amounts of digestive enzymes, have large amounts of rough ER and very little smooth ER. |
|
|
Term
| Name the three principle functions of the Golgi: |
|
Definition
1. Renewal/Modification of plasma membrane.
2. Modification and packaging of secretions for release through exocytosis.
3. Packaging special enzymes in vesicles for use in cytosol. |
|
|
Term
| What are the three general areas of the Golgi Ap? |
|
Definition
| Forming face, Cisternae, Maturing face. |
|
|
Term
| Explain the path proteins take from the ER through the Golgi App. |
|
Definition
| Proteins are packaged into transport vesicles which usually begin interaction with the Golgi app. by fusing with the Forming face. Proteins move from cistern to cistern through small vesicles and may be altered in the process. Eventually, proteins reach the Maturing face (final cistern), where they will leave via vesicles to their ultimate purpose. |
|
|
Term
| What are the three destinations for vesicles leaving the Golgi App. |
|
Definition
| Secretory vesicles fuse with the Plasma Membrane and dump their contents into the extracellular fluid. Lysosomes package enzymes for use within the cell. Membrane renewal vesicles fuse with the Plasma membrane, where the surface of the vesicle increases the surface area of the Plasma membrane. Conversely, parts of the plasma membrane can move inward, pinching off and later fusing with the Golgi App. in order to decrease plasma membrane surface area. |
|
|
Term
| What are three basic functions of lysosomes? |
|
Definition
1. Fuse with the membrane of another organelle. This will cause the release of degradative enzymes which dissolve the organelle.
2. Fuse with a vesicle containing fluid or solid from outside the cell. One example of this is phagocytosis.
3. Autolysis or Autophagy: the release of large amounts of degradative enzymes into the cytosol following irreversible cell injury. Leads to necrosis. |
|
|
Term
| How does Apoptosis differ from autolysis? |
|
Definition
| Apoptosis is Programed Cell Death, and is both a physiological and pathophysiological phenomenon. Unlike autolysis, Apoptosis progresses in an orderly fashion to break down the cell. Some characteristics of Apoptosis are: blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation. |
|
|
Term
| What are the physiologic and pathologic conditions under which Apoptosis can occur? |
|
Definition
During development, it is necessary to remove cells that were originally placed. For example Apoptosis is used to remove the cells between the fingers, allowing for the differentiation of them.
Pathological causes of Apoptosis usually involve conditions which fatally injure the cell's DNA: radiation damage, cancer, and viral infection. Additionally, conditions which result in atrophy in an organ can trigger Apoptosis signals. |
|
|
Term
| "With the exception of ___________, all organelles are either interconnected or in communication through the movement of vesicles." |
|
Definition
|
|
Term
|
Definition
| The continuous movement and exchange of chemicals via vesicles. IN A ACTIVELY SECRETING CELL, AN AREA EQUAL TO THE ENTIRE MEMBRANE SURFACE MAY BE REPLACED EACH HOUR. |
|
|
Term
| Describe the structure of the mitochondrial membrane. |
|
Definition
| There is an inner and outer membrane. The outer membrane is smooth, while the inner membrane has numerous infolds, called Cristae. |
|
|
Term
| Explain the purpose of the Cristae's geometry. |
|
Definition
| The folds greatly increase surface area, allowing more sites for the metabolic enzymes. |
|
|
Term
| Explain the roll of energy production within the cytosol: |
|
Definition
Glycolysis, which cleaves glucose into two parts produces a net of 2 ATP.
This process costs 2 ATP to happen, and produces 4 ATP and 2 NADH. The latter are only useful if oxidative phosphorylation is available. |
|
|
Term
| Besides high-energy molecules, what is the end product of glycolysis? |
|
Definition
|
|
Term
| Explain the function of the Citric Acid Cycle: |
|
Definition
| To break down Pyruvate into carbon dioxide and hydrogen atoms. |
|
|
Term
| What are the hydrogen atoms used for? |
|
Definition
| They are delivered to enzymes on the surface of the Cristae, where they catalyze ATP synthesis. |
|
|
Term
| What percentage of ATP production is produced using aerobic metabolism? |
|
Definition
|
|
Term
| How many proteins can the nucleus code for? |
|
Definition
|
|
Term
| Describe the structure of the nuclear envelope: |
|
Definition
| The nuclear envelope is composed of a double membrane. Nuclear pores punctuate the surface (about 10% of the surface). |
|
|
Term
| What is the perinuclear space? |
|
Definition
| The space in between the two membranes of the nuclear envelope. |
|
|
Term
| What is the function of the nuclear envelope? |
|
Definition
| This membrane separates the nuclear material (DNA, RNA, nucleoplasm) from the cytosol. |
|
|
Term
| What is the function of the Nuclear Pores? |
|
Definition
| Permit chemical communication between cytosol and nucleus. |
|
|
Term
|
Definition
| The fluid component of the nucleus contents. |
|
|
Term
| What is the nuclear matrix? |
|
Definition
| A network of fine filaments within the nucleoplasm provides structural support and may be involved in the regulation of genetic activity. |
|
|
Term
| What other components are found in the nucleoplasm? |
|
Definition
| Ions, enzymes, RNA and DNA nucleotides and small amounts of RNA and DNA. |
|
|
Term
|
Definition
| These are temporary organelles that synthesize Ribosomal RNA. |
|
|
Term
| What are nucleoli composed of? |
|
Definition
| RNA, enzymes, and histone proteins. |
|
|
Term
| What cells are nucleoli most prominent in? |
|
Definition
| Those which make a lot of proteins: liver, nerve, muscles. |
|
|
Term
| What is the purpose of Histone? |
|
Definition
| It winds the DNA when it is not dividing so that it is not so long. |
|
|
Term
| What are the coiled complexes of DNA called? |
|
Definition
|
|
Term
| What is the loosely coiled tangle of DNA found under normal circumstances called? |
|
Definition
|
|
Term
| What happens to the coils of DNA at the start of cell division? |
|
Definition
| The coils become tighter and more complex until chromosomes are formed. |
|
|
Term
|
Definition
| The connecting point connecting the duplicates in the chromosomes. |
|
|
Term
| How many pairs of chromosomes are there in somatic cells? |
|
Definition
|
|
Term
| What is the triplet code? |
|
Definition
| The genetic code is organized in groups of three, with each iteration of three nitrogenous bases coding for a different amino acid. |
|
|
Term
| What are the four nitrogenous bases in DNA? |
|
Definition
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G) |
|
|
Term
|
Definition
| the functional unit of heredity...A section of DNA containing all the nucleotides needed to code for a specific protein. A gene's size depends on the size of the protein it codes for. |
|
|
Term
| What must happen before a section of DNA can be used to make protein? |
|
Definition
| It must be uncoiled and have its histones removed. |
|
|
Term
|
Definition
| The process that controls DNA preparation for protein synthesis. |
|
|
Term
| What happens after DNA has been unwound? |
|
Definition
| Messenger RNA (mRNA) is assembled by enzymes. The mRNA contains the complimentary base pairs to the DNA. |
|
|
Term
| What are the complimentary base pairs for DNA? |
|
Definition
|
|
Term
| What are the complimentary RNA-DNA base pairs? |
|
Definition
|
|
Term
| What are the triplets coded on the mRNA called? |
|
Definition
|
|
Term
| Where happens to the completed mRNA? |
|
Definition
| It passes through a nuclear pore to the cytoplasm. |
|
|
Term
|
Definition
| A complimentary triplicate to a codon on the mRNA. Each anticodon is part of a specific tRNA, which carries a specific amino acid. |
|
|
Term
| What is the function of the Ribosomal RNA (rRNA)? |
|
Definition
| String together amino acids in the order they are presented by the tRNA. |
|
|
Term
|
Definition
| The production of RNA from DNA. |
|
|
Term
| Explain the steps of Gene Activation: |
|
Definition
1. Disruption of hydrogen bonds
2. Removal of histone guarding Control Segment (first segment of Gene) |
|
|
Term
|
Definition
| The enzyme that helps form hydrogen bonds between the DNA bases and their complimentary RNA bases. |
|
|
Term
| How are mRNA bases attached to each other? |
|
Definition
|
|
Term
| What happens when mRNA polymerase reaches the "stop" signal in the DNA strand? |
|
Definition
| The enzyme detaches, transcription ends, and the complimentary DNA strands come back together. |
|
|
Term
| What is immature or pre-RNA? |
|
Definition
| mRNA before the removal of non-functional triplets. |
|
|
Term
| What are introns and exons? |
|
Definition
Introns are the non-functional or nonsense regions of the mRNA that have to be removed before meeting up with tRNA.
Exons are the functional parts of the mRNA that are the spliced together. |
|
|
Term
| Does each gene code for only one protein? |
|
Definition
| No. By controlling which introns are removed, the gene can code for different proteins. |
|
|
Term
|
Definition
| The formation of linear chains of amino acid based on the mRNA sequence. The nucleotide sequence is "translated" into an amino acid sequence. |
|
|
Term
| Describe the steps of Translation, including the functioning of the ribosome: |
|
Definition
1. mRNA binds to small ribosomal subunit.
2. First tRNA binds to start codon of mRNA.
3. Large ribosomal subunit interlocks around mRNA.
4. 2nd tRNA with anticodon moves into 2nd space in ribosome.
5. Ribosome connects the two amino acids.
6. The first tRNA (without its amino acid) leaves the ribosome. The second moves over to where the first was as the ribosome moves down 1 codon.
7. A third tRNA moves into the spot that was formally occupied by the second.
8. The amino acids on the second tRNA are attached by the ribosome to the new tRNA's amino acid. The second tRNA leaves.
9. This continues until the stop signal.
10. The ribosomal units detach, leaving the intact mRNA strand and a polypeptide. |
|
|
Term
| How long does the translation process take? |
|
Definition
| About 20 seconds for a typical protein. |
|
|
Term
| Does the mRNA code for only a single protein? |
|
Definition
| A single mRNA strand can be used to produce many copies of the same protein over minutes to hours before being broken down. |
|
|
Term
| Can multiple ribosomes be used to make the same protein? |
|
Definition
| No, but multiple ribosomes can be attached to the same mRNA to simultaneously make multiple protein copies. |
|
|
Term
| What is the property of the plasma membrane that determines what substances can cross it? |
|
Definition
|
|
Term
| What differences in materials can be selectively allowed or blocked by selectively permeable membranes? |
|
Definition
| Size, electrical charge, molecular shape, lipid solubility, or other factors. |
|
|
Term
| Do all cells share the same membrane permeability? |
|
Definition
| No, differences in lipids and proteins in the plasma membrane cause different cells to have different membrane permeabilities. |
|
|
Term
| What is the difference between passive and active transport. |
|
Definition
| Active transport requires ATP. |
|
|
Term
|
Definition
| The movement of molecules down a concentration gradient. |
|
|
Term
| What is carrier-mediated transport, and is it passive or active? |
|
Definition
| It is transport via carrier proteins. It can be passive or active. |
|
|
Term
| What is vesicular transport and is it passive or active? |
|
Definition
| The transport of molecules by being enveloped by a vesicle and take into the cell. This is active. |
|
|
Term
| What is diffusion driven by? |
|
Definition
| The innate motion of molecules, and the tendency of this movement to spread out a collection of molecules over time. |
|
|
Term
| What happens to the motion of molecules after they have spread out evenly? |
|
Definition
| The motion of the molecules continues, but there is no further NET movement of molecules from one place to another. |
|
|
Term
| What factors influence diffusion rates? |
|
Definition
Distance - the shorter the faster.
Size - the smaller the faster.
Temperature - the hotter the faster.
Gradient - the steeper the faster (the greater the difference in concentration of solute from one area to another).
Electrical forces - Opposites attract, alike repel. This can work for or against diffusion speed. |
|
|
Term
|
Definition
| The diffusion of water through solutes. |
|
|
Term
| Explain the concept of Osmosis, esp. across semi-permeable membranes. |
|
Definition
| Water is a molecule, too, and if there is a semi-permeable membrane that restricts the movement of solutes, and a concentration difference between the two areas separated by this membrane, the water will diffuse across the membrane towards the side with a higher solute concentration. In effect, the water is moving DOWN its concentration gradient. |
|
|
Term
|
Definition
| The movement of water driven by osmosis. |
|
|
Term
| What is osmotic pressure? |
|
Definition
| The force of the water moving into the solution of higher solute concentration. |
|
|
Term
| What is hydrostatic pressure? |
|
Definition
| Pressure exerted by a fluid. |
|
|
Term
|
Definition
| How much solute there is in a solution (osmotic concentration). |
|
|
Term
|
Definition
| Osmolarity in regards to cells. |
|
|
Term
|
Definition
| The concentration of solutes does not cause a net flow of water in or out of a cell through osmosis (same effective concentration of solutes outside and inside of cell). |
|
|
Term
|
Definition
| A solution that cause a flow into the cell (lower effective concentration of solutes outside the cell as in.) This can cause the cell to SWELL and pop like a balloon (Hemolysis). |
|
|
Term
|
Definition
| Concentration of solutes that causes water to flow out of cell (Higher effective concentration of solutes outside the cell as in). Leads to shrinkage and Crenation of cell. |
|
|
Term
|
Definition
| An isotonic solution comprised of 0.9% Sodium Chloride. |
|
|
Term
| What kinds of molecules do carrier proteins move? |
|
Definition
| Lipid insoluble and ones that are too large to fit through a membrane channel. |
|
|
Term
|
Definition
| Moving more than one substance in the same direction siumultaneously. |
|
|
Term
| What is countertransport? |
|
Definition
| Moving two substances in opposite directions. |
|
|
Term
| What are carrier proteins that perform countertransport called? |
|
Definition
|
|
Term
| Explain how Facilitated Transport works: |
|
Definition
| A molecule moves down its concentration gradient by way of a carrier protein. It binds to a receptor site on one side of the membrane. The protein changes shape, moving the molecule into a position where it can disengage and have access to the cytosol. |
|
|
Term
| Does a higher concentration gradient speed up movement with Facilitated Transport. |
|
Definition
| To a point...once all carrier proteins are saturated, further increases in concentration gradient don't increase movement speed across membrane. |
|
|
Term
| What is a key advantage of active transport? |
|
Definition
| It can move molecules AGAINST the concentration gradient. |
|
|
Term
| Explain how the Na/K ATPase pump works: |
|
Definition
| By using 1 ATP, this pump moves 3 Na out of the cell at the same time it moves 2 K into the cell. |
|
|
Term
| Explain Secondary Active Transport, and give an example: |
|
Definition
The carrier protein doesn't require energy, but energy will need to be expended, nonetheless, in order to maintain homeostasis because of the way the pump works.
An example is a carrier protein that passively moves 1 Na into the cell along with 1 glucose. If this transport continues functioning, Na levels in the cell will increase to unacceptable levels. A Na pump will have to be employed to move Na back out of the cell, and this will cost ATP. |
|
|
Term
| What are the two main categories of vesicular transport? |
|
Definition
| Endocytosis and exocytosis. |
|
|
Term
|
Definition
| The formation of vesicles at the cell surface. |
|
|
Term
|
Definition
| This is the name for the vesicle formed during endocytosis. |
|
|
Term
| What is receptor-mediated endocytosis? |
|
Definition
| Endocytosis that is set in motion by the interaction of a carrier protein with specific recognition substances like Fe++ or cholesterol on its surface. These interact with receptors and set in motion endocytosis. |
|
|
Term
| Explain the steps of receptor-mediated endocytosis: |
|
Definition
1. Materials bind to receptors on membrane surface. Most receptors are ligand-specific.
2. An area of receptors is covered in ligands. Once enough receptors are covered, this area begins to move inward forming a groove, then a pocket.
3. The sides of the cell membrane surrounding the pocket move towards each other until they meet and pinch off. This pocket is now a sealed vesicle.
4. This vesicle is called a Coated Vesicle because the inside is coated with a protein-fiber network.
5. The coated vesicle fuses with lysosomes.
6. The lysosome enzymes free the ligands from their receptors and the ligands enter the cytosol by diffusion or active transport.
7. The vesicle membrane detaches from the lysosome.
8. The vesicle membrane fuses again with the surface membrane and is ready to bind with ligands again. |
|
|
Term
|
Definition
| "Cell Drinking" - the formation of endosomes filled with extracellular fluid. |
|
|
Term
| Compare pinocytosis to receptor-mediated endocytosis. |
|
Definition
| Though vesicle creation is similar, pinocytosis is less selective in the material enclosed because of the lack of receptor-ligand binding. |
|
|
Term
|
Definition
| "Cell Eating" - this is the envelopment and digestion of large, solid objects, such as bacteria. |
|
|
Term
| What kind of cells can perform phagocytosis? |
|
Definition
| Only phagocytes or macrophages. |
|
|
Term
| What is produced when a bacteria is enveloped by a phagocyte? |
|
Definition
| A Phagosome, analogous to a vesicle, but much larger, and irregularly shaped, is formed within the cytosol. |
|
|
Term
| Explain the steps of Phagocytosis: |
|
Definition
| Cytoplasmic extensions (pseudopodia) surround the object, then fuse their tips together, engulfing the object. The container (phagosome) fuses with a lysosome, which deliver digestive enzymes into the phagosome to break down the object. Nutrients are released into the cytosol, while the rest is ejected from the cell by exocytosis. |
|
|
Term
|
Definition
| The release of material to the extracellular environment by the fusing of the vesicle to the plasma membrane. |
|
|
Term
| How many cells are there in the human body at maturity? |
|
Definition
|
|
Term
|
Definition
| Genetically controlled death of a cell - it is orderly and efficient, as compared with cell necrosis. |
|
|
Term
|
Definition
| The production of two daughter cells, each with a complete set of 46 chromosomes (normal cell division). |
|
|
Term
|
Definition
| The production of sex cells, which only have 23 chromosomes. |
|
|
Term
|
Definition
| The period of the cell life cycle when the cell is NOT actively dividing. |
|
|
Term
| When are the chromosomes duplicated? |
|
Definition
|
|
Term
|
Definition
| The division of the cytoplasm, which ends the period of mitosis and results in two daughter cells. |
|
|
Term
|
Definition
| The two cells resulting from mitosis. They both have the complete set of 46 chromosomes, but are have the size of the original cell. |
|
|
Term
| What are the phases of Interphase, in order? |
|
Definition
|
|
Term
|
Definition
| This is the part of interphase where no preparation for cell division is occurring. Normal cell functions occur. |
|
|
Term
| What cells remain in Go indefinitely? |
|
Definition
| Skeletal muscles and neurons. |
|
|
Term
| What cells never enter Go? |
|
Definition
|
|
Term
| What happens during the G1 phase? |
|
Definition
| The creation of two sets of the necessary organelles: mitochondria, Golgi App, ER, cytoskeletal elements, ribosomes, cytosol. Centriole replication begins and usually continues through G2. |
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Term
| How long can G1 phase? last? |
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Definition
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Term
| What happens during S phase? |
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Definition
| Duplication of chromosomes, histones, and nucleic proteins. |
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Term
| How long does S phase last? |
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Definition
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Term
| What happens during the G2 phase? |
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Definition
| This is a period after DNA replication when additional proteins are synthesized and centriole replication completed. |
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Term
| How long does G2 phase last? |
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Definition
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Term
| What are the phases of Mitosis, in order? |
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Definition
| Prophase Metaphase Anaphase Telophase |
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Term
| How long does Mitosis take? |
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Definition
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Term
| Summarize the times needed for all phases of cell life: |
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Definition
| Go: very short to indefinite
G1: 8 or more hours
S: 6-8 hours
G2: 2-5 hours
Mitosis: 1-3 hours. |
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Term
| Describe the steps of DNA replication: |
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Definition
1. Enzymes unwind strands and disrupt hydrogen bonds between bases.
2. DNA polymerase molecules bind to these exposed bases. This enzyme encourages binding between the strand and free floating complimentary bases in the necleoplasm and links the arriving complimentary bases together with covalent bonds.
3.The unzipping of the strand and work of DNA polymerase molecules continues until there are two complete sets of DNA. |
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Term
| How does the work of DNA polymerase differ between the two unwinding strands? |
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Definition
| DNA polymerase can only work towards the "zipper" on one strand and away from the "zipper" on the other. The former simply attaches at the end, and works continuously towards the zipper as the two strands separate. The latter must use multiple DNA polymerase molecules which "hop on" to the strand near the zipper point and work away from it. As they reach a section of DNA that has already been duplicated by another DNA polymerase molecule, the ends of the complimentary bases are spliced together. |
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Term
| What is the name of the enzyme that splices together the complimentary base sections added during DNA replication? |
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Definition
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Term
| Compare mitosis vs. cytokinesis: |
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Definition
Mitosis is the division and duplication of the cell's nucleus.
Cytokinesis is the division of the cytoplasm into two distinct cells. |
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Term
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Definition
- The chromosomes coil tightly enough to be visible under light microscope.
- The pairs of centrioles move to opposite sides of the nucleus.
- Microtubules are visible in two types: Astral rays, looking like a corona around the centrioles extend into the cytoplasm. Spindle fibers connect to the Kinetochores on the Chromatids.
- The nuclear membrane disintegrates. |
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Term
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Definition
| The Chromatids move towards the a narrow central zone called the Metaphase plate. When they are lined up, Anaphase begins. |
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Term
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Definition
| The Chromatid centromere splits, and the chromosomes are separated and pulled along the spindle fibers. |
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Term
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Definition
- Creation of new nuclear envelopes.
- Enlargement of nuclei.
- Uncoiling of DNA.
- Thus ends Mitosis |
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Term
| Describe Cytokinesis and the phases it occurs during: |
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Definition
| Separation of the cells begins as the plane of the metaphase plate begins to cleave inward. This process begins during anaphase and competes during telophase. |
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Term
| What is the cause of cancer? |
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Definition
| Permanent alterations to the DNA (mutations) which disrupt normal control mechanisms of cell division. |
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Term
| Which tissues are the most common to have cancer in? |
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Definition
| Because during mitosis, there is a chance of an error occurring during DNA replication, cells that divide rapidly and continuously are more likely to get cancer. E.g. epithelial cells in intestines or skin. |
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Term
| What is a tumor or neoplasm? |
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Definition
| A mass or swelling caused by abnormal cell growth and division. |
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Term
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Definition
| A tumor that remains within its original tissue. |
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Term
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Definition
A tumor that has some of these properties:
- Divides very rapidly, releasing chemicals to stimulate blood vessel growth to support it.
- Metastasis: cells that break off from the original tumor to create other tumors elsewhere. |
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Term
| How does the cancer kill the patient? |
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Definition
Destruction of vital processes by replacing useful cells with useless cells. Compression of vital organs.
Increased or decreased creation of key hormones or enzymes. |
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