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190 Cards in this Set
- Front
- Back
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___ are the structural units of all living things
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cells
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Name for four concepts collectively know as cell theory.
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1. A cell is the basic structural and functional unit of living organisms. So when you define cell properties you are in fact defining the properties of life.2. The activity of the organism depends on both the individual and collective activities of its cells.3.According to the principle of complimentarity, the biochemical activities of cells are dictated by the relative number of their specific subcellular structures.4. Continuity of life has a cellular basis.
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Humans cell have three basic parts, what are they?
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Plasma membrane, cytoplasm, nucleus.
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___ fluid lies inside of cells, while ___ lies outside of cells
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intracellular, extracellular
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The __ __ model of membrane structure depicts the membrane as a thin structure composed of a bilayer of lipid molecules with protein molecules dispersed in it.
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fluid mosaic
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Each phospoholipid molecule has a polar head that is charged and __, and a nonpolar tail that is made of two fatty acid chains and is ___.
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hydrophilic, hydrophobic
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____, or phosphates with attached sugar groups, are found only on the outer plasma membrane and account for _% of the total membrane lipid.
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glycolipids, 5%
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About __% of membrane lipid is cholesterol.
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20
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About 20% of the out membrane surface contains __ __, dynamic assemblies of saturated phospholipids
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lipid rafts
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___ proteins are firmly inserted in to the lipid bilayer.
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integral
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___ proteins span the entire width of the membrane.
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transmembrane
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All integral proteins have both ___ and ___ regions.
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hydrophilic, hydrophobic
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Two ways transmembrane proteins can transport molecules are as ___ and ___
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channels, carriers
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In contrast to transmembrane proteins, __ proteins are not embedded in the lipid.
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Peripheral
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The term ___ is used to describe the fuzzy, sticky, carbohydrate-rich area at the cell surface.
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glycocalyx
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The glycocalyx provides highly specific ___ ___ by which approaching cells recognize each other.
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biological markers
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___ are minute, fingerlike extensions of the plasma membrane that project from a free, or exposed, cell surface.
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microvilli
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Microvilli have a core of __ filaments.
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actin
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what 3 factors act to bind cells together?
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-glycocalyx, shape, junctions-glycoproteins in the glycocalyx act as an adhesive, wavy contours of the membranes of adjacent cells fit together in a tongue and groove fashion, special membrane junctions are formed.
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Name the 3 types of cell junctions.
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Tight junctions, gap junctions, desmosomes
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This junction helps prevent molecules frpm passing through the extracelular space between cells
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tight junction
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This junction is abundant in tissues subjected to great mechanical stress, such as skin and heart muscle
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desmosomes
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This junction is present in electrically excitable tissues where ion passage helps synchronize their electrical activity and contraction.
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gap junction
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Ou cells are bathed in an extracellular fluid called __ __.
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interstitial fluid
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In ___ transport processes, substances cross the membranne without any energy output from the cell.
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passive
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In __ transport processes, the cell provides the metabolic energy (__) to move substances across the membrane.
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active, ATP
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The two main types of passive transport in cells is ___ and ___
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diffusion and filtration
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___ is the tendancy of molecules or ions to scatter evenly throughout the environment.
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diffusion
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The speed of diffusion is influenced by ___ and ___
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molecular size and temp.
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A molecule will diffuse through the cell membrane if the molecule is meets one of 3 factors. Whate are those factors?
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lipid soluble, small enough to pass through a membrane channel, or assited by a carrier molecule.
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The unassisted diffusion of lipid soluble or ver small particles is called ___ diffusion.
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simple
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In __ diffusion, the transported substance passes thru the membrane by either 1-binding to ptotein carriers or 2-moves thru water filled protein channels
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facilitated
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Channels are selective due to __ size and the __ of the amino acids lining the channel.
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pore, charges
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The rate of facilitated diffusion is/is not controllable.
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is
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the rate of simple diffusion is/is not controllable
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is not.
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Define osmosis.
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The diffusion of a solvent thourgh a selectively permeable membrane.
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Water flows freely thru transmembrane proteins called __
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aquaporins (AQP)
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The total concentration of all solute particles in a solution is referred to as the solutions ___
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osmolarity
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Define hydrolized.
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Borken apart by the addition of water to covalent bonds.
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The major positive ion of extracellular fluid is __, and the major negative ion is __.
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Na+, Cl-
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The major positive ion of the intracellular fluid is __, and the major negative ions are __ and __.
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K+, protein and phosphates
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In which area of the nephron is most of the sodium reabsorbed?
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Loop of Henle
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In the nephron, in the presence of aldosterone, where would the residual sodium go to?
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into the urine
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In the presence of of aldosterone, where in the nephron would the remaining sodium be reabsorbed?
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DCT
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In what area of the nephron is potassium reabsorbed?
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PCT
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The higher the amount of non diffusable (or non nenetrating) solutes in a cell, the ___ the osmotic pressure, and the ___ the hydrostatic pressure that must be developed to resist further (net) water entry.
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higher, greater
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The ability of a solution to change the shape or tone of cells by altering their internal water volume is called ___
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tonicity.
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Solutions with the same concentrations of nonpenatrating solutes as those found in cells are ___.
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isotonic
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What is the percentage of saline and glucose found in cells?
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0.9% saline, 5% glucose.
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Solutions with a higher concentration of nonpenetrative solutes than seen in a cell are ____.
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hypertonic
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Cells immersed in hypertonic solutions lose water and shrink, or ___.
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crenate
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Solutions that are more dilute than cells are called ____.
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hypotonic
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___ water represents the most extreme example of hypotonicity
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distilled.
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If is cell is placed in distilled water, what will happen?
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water will continue to enter the cell until it finally burst or lyse.
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Tonicity of a solution is base on what two things?
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solute concentration and solute permeability of the plasma membrane
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In general, osmosis continues until what happens?
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osmotic and hydrostatic pressures acting at the membrane are equal.
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___ is the process that forces water and solutes throgh a membrane or capillary wall by hydrostatic pressure.
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filtration
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Filtration is a ____ transport process.
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passive
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Filtration pushes solute contataining fluid from a ___ pressure area to a __ pressure area
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high, low
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Filtration is/is not a selective process.
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is not
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Primary active transport processes utilize __ as energy.
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ATP
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Active transport require carrier proteins that combine __ and __ with the transported substances.
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specifically and reversably
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Name two reasons for using active processes.
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Transporting substances either too large to pass through the membrane, or to transport against the concentration gradient.
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Active transporters can also be referred to as ___ pumps in regards to there transport of ions.
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solute
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Secondary active transport systems are ___, meaning they move more than one substance at a time.
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coupled
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With secondary active transport systems, if the two substances are moved in the same direction, the system is a ___ system.
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symport.
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With secondary active transport systems, if the two substances are moved in the different directions, the system is a ___ system.
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antiport
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Vesicular transport is the mechanism used for ____, moving substances from the cell interior to the extracellular space.
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exocytosis
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Vesicular transport is the mechanism used for ____, moving substances from the extracellular space to the cell interior.
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endocytosis
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Vesicular transport uses what two enrgy sources?
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ATP, GTP-guanosine triphosphate
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___ coated vesicles are hijacked on occasionally by pathogens seeking entry into a cell.
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clathrin.
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____ is common in endothelial cells lining blood vessels because it provides quick means to get substances from the blood to the interstitial fluid.
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trancytosis
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The three types of endocytosis that use clathrin-coated vesicles are
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PPR-phagocytosis, pinocytosis, receptor mediated endocytosis
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Psuedopods have formed and flow around bacteria and engulf it. What type of endocytosis is taking place?
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phagocytosis
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The endocytotic vesicle formed during phagocytosis is called a __
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phagosome
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In most cases, the contents of a phagosome fuse with a ___ and it's contents are digested.
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lysosome
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Briefly describe ameboid motion.
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phagocytes flow their cytoplasm into temporary pseudopods and that allows them to move.
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___ is used by the cells that absorb nutrients in the intestines, where the droplet of extracellular fluid enters the cell and fuses with an endosome.
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pinocytosis
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___ ___ endocytosis the the main mechanism for the specific endocytosis and transocytosis of most macro molecules by body cells.
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Receptor mediated endocytosis
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Voltage across the membrane is know as the ___ ___.
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membrane potential
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The inside of the cell is charged ___ compared to the outside
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negatively
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The cell membrane is much more permeable to __ then to __ at rest
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K+ than to Na+
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The resting membrane potential is determined mainly by the concentration gradient of __
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K+
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In most cases Cl- does/does not contribute to the resting membrane potential.
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does not
(even the the cell is permeable to Cl-, its entry is resisted by the negative charge on the interior) |
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The rate of active transport is is equal to, and depends on, the rate of ___ diffusion into the cell.
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Na+
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In the sodium/potassium pump, on average each pump ejects 3Na+ out of the cell and carries _K+ back in.
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2K+, 3:2 ratio
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Ions diffuse according to their ___-___ gradient.
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electro-chemical
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What are the two sticky glycoproteins found in cell adhesion molecules (CAMs)?
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cadherin, integrin
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Signaling chemicals that bind directly to plasma membrane receptors are called ___.
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ligands.
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Intracellular chemical messengers are reffered to as __ __
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second messangers
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Name two very important second messengers.
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cyclic AMP and ionic calcium
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Cyclic AMP and ionic calcium typically activate what?
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protein kinase enzymes.
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Name the signaling molecule that is known to be an environmental pollutant.
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Nitric Oxide (NO)
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The ___ is the cellular material between the plasma membrane and the nucleus
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cytoplasm
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____ is the viscous, semi-transparent fluid in which the other cytoplasmic elements are suspended.
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cytosol
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___ are chemical substances the are present depending on cell type. Examples are melanin, lipid droplets in fat cells.
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inclusions
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Most organelles have a membrane similar to the plasma membrane, minus the ___
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glycocalyx
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___ are the power plants of the cell, providing most of it's ATP supply.
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Mitochondria
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Mitochondria are enclosed by how many membranes?
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2
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The gel like substance in the mitochondria is referred to as the __
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matrix
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The inner membrane of mitrochondria folds inwards forming what?
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cristea, shelflike crests
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Mitochondria can/cannot reproduce themselves, and do/do not contain there own RNA and DNA.
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can, do
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When cellular requirements for ATP increase, what are to responses by the mitochondria?
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They synthesize more cristea, or they pinch in half to increase their numbers (fission)
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Free ribosomes have what function?
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make soluble proteins that function in the cytosol.
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Membrane bound ribosomes have what function?
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synthesize proteins destined either for incorporation into cell membranes or for export from the cell.
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Name the functions of the rough ER.
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its ribosomes produce all proteins secreted from the cell, it is the cells "membrane factory", the enzymes needed to catalyze lipid synthesis are located on the external face of the ER membrane.
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Name the functions of the smooth ER.
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lipid metabolism, synthesis of steriod based hormones, absorbtion synthesis-transport of fats (intestinal cells), detoxification of drugs, and breakdown of stored glycogen to form free glucose.
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What is the main function of the golgi apparatus?
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to modify, concentrate, and package the proteins and lipids made at the rough ER, and to package digestive enzymes into membranous lysosomes
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Physically, caveolae are ___ and their coat is ___ than clathrin coated vesicles.
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smaller, thinner
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The trans face is know as the __ side of the golgi apparatus.
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shipping side.
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The cis face is known as the __ side of the golgi apparatus.
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receiving
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Lysosomal rupture results in self digestions of the cell, a process called ___
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autolysis
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Lysosomes are known as the cells "__ crew"
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demolition
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Lysosomes provide sites where digestions can happen ___ within a cell.
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safely
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In __ __ disease, lysosomes lack an enzyme needed to break down a glycolipid abundant in nerve cell membranes.
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Tay sach's
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Name two normal by-products of cellular respiration.
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free radicals and hydrogen peroxide
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Oxidases convert __ __ to hydrogen peroxide.
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free radicals
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Peroxisomes contain a variety of important enzymes. Name the two most important
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oxidases, and catalases
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Catalses convert __ __ to water
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hydrogen peroxide
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Peroxisomes are __ replicating oraganelles, and are not produced by budding from the Golgi apparatus.
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self
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Name the three types of rods, smallest to largest, in the cytoskeleton.
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Microfilaments, intermediate filaments, and microtubules.
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Unlike microtubules and microfilaments, intermediate filaments do/do not bind to ATP.
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do not
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Microtubules are made from sphereical protein subunits called ___.
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tubulins
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Most microtubules radiate from a small region of cytoplasm near the nucleus called the ____.
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centrosome
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Mitochondria, lysosomes, and secretory granules attach to the __ like ornaments hanging from tree branches
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microtubules
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___ are the most stable and permanent of the cystoskeletal elements and have high tensile strength.
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intermediate filaments
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What organelle acts as the microtubule organizing center?
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centrosome
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The centrosome matrix is best known for what two functions?
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generation of microtubules, and organizing the mitotic spindle in cell division.
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Centrioles form the basis of __ and __.
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cilia and flagella
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The single example of a flagellated cell in the human body is the __.
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sperm
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Centrioles forming the bases of cilia and flagella are commonly referred to as what?
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basal bodies
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Decribe the pattern of microtubles in cilium and flagellum, and contrast to that of a centriole.
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9 doublets of microtubules, encircling one central pair, compared to 9 triplets and on central pair in a centriole.
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In cilia, extending from the arms of microtubule doublets are arms of the motor protein ___.
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dynein.
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Give 3 examples of multinucleate cells.
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skeletal muscle cells, bone destruction cells, and some liver cells
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What is the one exception to all of our cells being nucleated?
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mature erythrocytes.
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Name the only anucleate cell in our body.
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mature erythrocytes in the bloodstream.
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Name the 3 basic structures in a nucleas.
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Nuclear envelope, nucleoli, chromatin.
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What is the name of the jelly-like fluid inside the nuclear envelope?
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nucleoplasm
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Name the fundamental unit of chromatin.
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nucleosomes.
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Name the two major life cycle periods of a cell.
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Interphase, miotic phase (cell division)
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___ is described as the period from cell formation to cell division.
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interphase
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What 3 subphases phases make up interphase?
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G1, S, G2
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Cells that premanently cease dividing are said to be in G_ phase.
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0
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G_ phase is the most variable phase in terms of length.
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G1
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During _ phase, DNA is replicated.
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S
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What is the name of the enzyme that untwists the DNA molecule into two complimentary nucleotide chains.
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helicase.
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____ are nucleoprotein caps that prevent degradation of the ends of the chromatin strands.
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telomeres
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What are the four stages of Mitosis?
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PMAT, Prophase, Metaphase, Anaphase, Telophase.
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Cytokinesis begins at what stage of Mitosis?
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late anaphase
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The contractile ring is made up of what filaments?
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Actin
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Mitosis is to the division of the nucleas as __ is to the division of the cell.
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cytokinesis
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Name the two groups of proteins which are crucial for the ability of the cell to accomplish the S phase and enter mitosis.
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cyclins and Cdks (cyclin dependent kinases)
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At the end of mitosis, cyclins are abruptly destroyed by ___.
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proteasomes.
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A threshold amount of ___ is required to give the ok signal to pass the G2 checkpoint and enter M phase
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MPF (M-phase promoting factor)
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What two groups of proteins are crucial to the ability of a cell to accomplish the S phase and enter mitosis?
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cyclin and Cdks (cyclin-dependant kinases)
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What is the longest phase of mitosis?
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prophase
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In metaphase, the arrangement of the chromosomes along a plane midway between the poles is called the ___ plate.
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metaphase
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Anaphase is easy to regognize because the moving chromosomes look _ shaped
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V
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What is the shortest stage of mitosis?
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Anaphase
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The nuclear envelope fragments in which stage?
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Late prophase
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Regarding genes, each sequence of three bases specifies a particular ___
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amino acid.
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What are the 3 types of RNA?
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TRiM
Transfer Ribosomal Messenger |
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Ribosomal RNA and and tRNA act together to translate the message carried by ____
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mRNA
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Polypeptide synthesis involves two major steps. What are they?
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Transcription-DNA's info is encoded into mRNA
translation-info carried by mRNA is decoded and used to assemble polypeptides |
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The corresponding 3 base sequence on mRNA is called what?
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codon
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How many of the 64 codons are "stop signs"
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3
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The development of specific and and distinctive features in cells is called what?
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cell differentiation
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Programmed cell death is called
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apoptosis
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Intracellular enzymes that destroy the cell itself are called
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capases
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Define hyperplasia
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accelerated growth
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Define atrophy
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a decrease in size of an organ or body tissue
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Define anaplasia
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abnormalities in cell structure
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Define dysplasia
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a change in cell size, shape, or arrangement due to chronic irritation or inflammation
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Define necrosis
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death of a cell or group of cells due to injury or disease.
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As Mitosis begins, microtubule arrays called ___ are seen extending from the centrosome matrix around the centrioles.
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asters
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In stages of mitosis, the stage ___ begins as soon as chromosomal movement stops.
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telophase
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In stages of mitosis, the stage ___ begins as the centromeres split.
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anaphase
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___ are extensions of the plasma membrane that increae the surface area for absorbtion.
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microvilli
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In muscle cells, the smooth ER acts as a __ depot.
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Ca
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Define gene.
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a Gene is difined as a DNA segment that provides the instrustions for the synthesis of one polypeptide chain.
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The two major types of lipids found in the plasma membrane are
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cholesterol, phospholipids
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A person drinks a 6 pack of beer and has to make several trips to the bathroom. The increase in urination reflects an increase in what process occuring in the kidneys?
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filtration
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The term used to decribe the type of solution in which cells wil lose water to their environment is ___.
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hypertonic
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The solute pumping type of active transport is accomplished by ____
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phagocytosis
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The nuclear substance composed of histone proteins and DNA is
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chromatin
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The information sequence that determines the nature of a protein is the ___
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gene
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The phase of mitosis during which centrioles reach the poles and chromosomes attach to the spindle is ___.
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prohase
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Final preparations for cell division are made during the life cucle subphase called ___.
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G2
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If DNA has a sequence of AAA, then a segment of mRNA synthesized on it will have a sequence of ___
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UUU
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A pancreas cell makes proteins which it releases to the small intestines. Describe the path of the proteins from synthesis to exocytosis?
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Rough ER->Golgi apparatus->plasma membrane
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