| 6411346614 | cells | these are life's basic units of structure and function; all living things are composed of these
These are the smallest units of living material that can carry out all the activities necessary for life. | | 0 |
| 6411354397 | light microscope | an instrument used to study stained or living cells (can see bacteria) | | 1 |
| 6411357987 | electron microscope | an instrument used to study detailed structures of a cell capable of resolving structures as small as a few nanometers in length | | 2 |
| 6411364866 | eukaryotic (cells) | cells that contain a membrane-bound structure called a nucleus and cytoplasm, filled with tiny structures called organelles
Ex.) fungi, protists, plant cells, animal cells |  | 3 |
| 6411368699 | prokaryotic (cells) | smaller cells that lack both a nucleus and membrane-bound organelles; most of these have a cell wall composed of peptidoglycan, and may also have ribosomes as well as one of more flagella
The genetic material in one of these cells is one continuous, circular DNA molecule that lies free in the cell in an area called the nucleoid.
Ex.) bacteria |  | 4 |
| 6411394303 | nucleoid | This structure in a prokaryote contains one continuous, circular DNA molecule that lies free in the cell. |  | 5 |
| 6411399120 | peptidoglycan | For most prokaryotes, this substance composes the cell wall. | | 6 |
| 6411401816 | flagella | long projections from prokaryotes used for motility (movement) |  | 7 |
| 6411417867 | plasma membrane | an outer envelope of a cell that is a complex, double-layered structure made up of phospholipids and proteins (the hydrophobic fatty acid tails face inward and the hydrophilic phosphate heads face outward)
This is important because it regulates the movement of substances into and out of the cell. It is semipermeable, meaning that only certain substances, namely small hydrophobic molecules, pass through it unaided. |  | 8 |
| 6411437852 | peripheral proteins | proteins loosely bound to the plasma membrane (not embedded within) that are located on the inner or outer surface of the membrane | | 9 |
| 6411449217 | integral proteins | proteins that are firmly bound to the plasma membrane that are amphipathic
penetrate the hydrophobic core of the lipid bilayer, often completely spanning the membrane (as transmembrane proteins, meaning that they do not extend all the way through the membrane) | | 10 |
| 6411460369 | amphipathic | term used to describe proteins whose hydrophilic regions extend out of the cell or into the cytoplasm while their hydrophobic regions interact with the tails of the membrane phospholipids | | 11 |
| 6411472338 | transmembrane proteins | integral proteins spanning the membrane that do not extend all the way through the plasma membrane | | 12 |
| 6411482685 | fluid mosaic model | a diagram of the arrangement of phospholipids and proteins |  | 13 |
| 6411509539 | adhesion proteins | plasma membrane proteins that form junctions between adjacent cells
attach cells to neighboring cells or provide anchors for the internal filaments and tubules that give stability to the cell | | 14 |
| 6411514710 | receptor proteins | plasma membrane proteins that serve as docking sites for proteins of the extracellular matrix or hormones
accepts signals and initiates responses; sensitive to the presence of specific extracellular molecules called ligands | | 15 |
| 6411523689 | transport proteins | plasma membrane proteins that form pumps that use ATP to actively transport solutes across the membrane
helps a certain substance or class of closely related substances to cross the membrane | | 16 |
| 6411533843 | channel proteins | plasma membrane proteins that form channels that selectively allow the passage of certain ions or molecules
proteins that provide passageways through the membrane for certain hydrophilic (water-soluble) substances such as polar and charged molecules | | 17 |
| 6411554465 | recognition and adhesion proteins | plasma membrane proteins, such as glycoproteins, that are exposed on the extracellular surface and play a role in cell regulation and adhesion | | 18 |
| 6417273915 | carbohydrate side chains | these are attached to the surface of some proteins on phospholipid bilayer | | 19 |
| 6519838002 | cholesterol | these molecules are found in the phospholipid bilayer because they help to stabilize membrane fluidity in animal cells | | 20 |
| 6519840427 | nucleus | the largest organelle that is the control center of the cell; contains chromosomes that contain heredity information
it not only directs what goes on in the cell- it is also responsible for the cell's ability to reproduce |  | 21 |
| 6519849777 | chromosomes | large structures in the nucleus of a cell that are organized DNA |  | 22 |
| 6519854570 | nucleolus | the most visible organelle within the nucleus where rRNA is made and where ribosomes are assembled |  | 23 |
| 6519865348 | ribosomes | the sites of protein synthesis; their job is to manufacture all the proteins required by the cell or secreted by the cell
round structures composed of two subunits; the structure is composed of RNA and proteins; they can be either free floating in the cell or attached to the endoplasmic reticulum |  | 24 |
| 6519882035 | endoplasmic reticulum | a continuous channel that extends into many regions of the cytoplasm; classified as two regions: rough and smooth |  | 25 |
| 6519890675 | rough ER | the region of the ER that is "studded" with ribosomes
proteins generated here are trafficked to or across the plasma membrane |  | 26 |
| 6519895203 | smooth ER | the region of the ER that lacks ribosomes
makes lipids, hormones, and steroids and breaks down toxic chemicals |  | 27 |
| 6519959166 | Golgi bodies | organelles that look like stacks of flattened sacs that modify, process, and sort the products after the ribosomes on the rough ER have completed synthesizing proteins
They're the packaging and distribution centers for materials destined to be sent out of the cell. They package the final products in little sacs called vesicles, and they are also involved in the production of lysosomes. |  | 28 |
| 6520025569 | mitochondria | the "powerhouses" of the cell that are responsible for converting the energy from organic molecules into useful energy for the cell (ATP)
has a double membrane consisting of an inner portion and an outer portion; the inner membrane forms folds known as cristae, which is where most of the production of ATP is done
Since they are the cell's powerhouses, you're likely to find more of them in cells that require a lot of energy. Muscle cells, for example, are rich in mitochondria. |  | 29 |
| 6520115097 | ATP (adenosine triphosphate) | the energy molecule used by cells | | 30 |
| 6520117406 | lysosomes | small, membrane-bound structures that carry digestive enzymes, which they use to break down old, worn-out organelles, debris, or large ingested particles
They make up the cell's cleanup crew, helping to keep the cytoplasm clear of unwanted flotsam. They contain hydrolytic enzymes that only function at acidic pH, which is enclosed inside the structure's lumen. |  | 31 |
| 6520218552 | centrioles | small, paired, cylindrical structures that are found within microtubule organizing centers (MTOCs) and they are most active during cellular division
When a cell is ready to divide, they produce microtubules, which pull the replicated chromosomes apart and move them to opposite ends of the cell. |  | 32 |
| 6520260391 | vacuole | "empty cavity" in the cell that is a fluid-filled sac that stores water, food, wastes, salts, or pigments |  | 33 |
| 6520287779 | peroxisomes | organelles that detoxify various substances, producing hydrogen peroxide as a byproduct; they also contain enzymes that break down hydrogen peroxide into oxygen and water
In animals, they are common in the liver and kidney cells. | | 34 |
| 6520304933 | cytoskeleton | a network of fibers that determines the shape of a cell; these fibers include microtubules and microfilaments | | 35 |
| 6520312107 | microtubules | made up of the protein tubular, they participate in cellular division and movement; these small fibers are an integral part of three structures: centrioles, cilia, and flagella | | 36 |
| 6520320767 | cilia | hairlike projections that extend from the plasma membrane and are used for locomotion |  | 37 |
| 6520346627 | flagellum | a long, whip-like filament that helps in cell motility | | 38 |
| 6520354294 | Euglena | unicellular organism that moves using its flagella; involved in asexual reproduction and has chloroplasts to absorb sunlight |  | 39 |
| 6520364737 | Paramecium | a single-celled freshwater animal that has a characteristic slipperlike shape and is covered with cilia; its cilia enable it to motor about in waterways and ponds |  | 40 |
| 6520374754 | microfilaments | important for movement like microtubules; these thin, rod-like structures are composed of the protein actin, are involved in cell mobility, and play a central role in muscle contraction | | 41 |
| 6520442540 | cell wall | a structure found only in plant cells that is made of cellulose and is a rigid layer just outside of the plasma membrane that provides support for the cell
It is found in plants, protists, fungi, and bacteria. | | 42 |
| 6520454365 | chitin | a modified polysaccharide that makes up the cell wall in fungi | | 43 |
| 6520492564 | chloroplasts | organelles in plant cells that are involved in photosynthesis; they contain chlorophyll, the light-capturing pigment that gives plants their characteristic green color | | 44 |
| 6520499895 | cell sap | a watery liquid in a plant cell's vacuole composed of dissolved sugars, mineral ions, and other solutes | | 45 |
| 6520589713 | plant cell | type of cell that...
-has a cell wall
-has chloroplasts
-has a very large vacuole
-does not have centrioles | | 46 |
| 6520601368 | animal cell | type of cell that...
-does not have a cell wall
-does not have chloroplasts
-has small vacuoles
-has centrioles | | 47 |
| 6520655309 | water | The lipid membrane has an open-door policy for substances that are made up of lipids. If a substance is hydrophilic, the lipid bilayer won't let it in. What is the one exception to the rule?
Although ______ molecules are polar (and therefore not lipid-soluble), they can rapidly cross a lipid bilayer through aquaporins, which are integral membrane proteins that regulate the flow of ______. | | 48 |
| 6520694814 | lipid | _____-soluble substances can traverse the plasma membrane without much difficulty. | | 49 |
| 6520697179 | simple diffusion | diffusion in which if there's a high concentration of a substance outside the cell and a low concentration inside the cell, the substance will move into the cell
In other words, the substances moves down a concentration gradient. |  | 50 |
| 6520706836 | passive transport | simple diffusion is another name for this kind of transport because it does NOT require energy | | 51 |
| 6520729060 | osmosis | a special type of diffusion that involves the movement of water
Ex. ) If a chamber containing water and a chamber containing a sucrose solution are connected by a semipermeable membrane that allows water but not sucrose to cross, diffusion of sucrose between the chambers cannot occur. In this case, _____ draws water into the sucrose chamber to reduce the sucrose concentration. This will reduce the total volume of the water chamber. Water will flow into the sucrose chamber until the concentration is the same across the membrane. | | 52 |
| 6520762521 | isotonic | term referring to a substance having the same solute concentration as another solution | | 53 |
| 6520747023 | hypertonic | term referring to substance having a higher concentration of solute than another solution | | 54 |
| 6520750241 | hypotonic | term referring to substance having a lower concentration of solute than another solution | | 55 |
| 6520877403 | tonicity | the ability of a surrounding solution to cause a cell to gain or lose water
If the environment is isotonic to the cell, the solute concentration is the same inside and outside. A hypertonic solution has more total dissolved solutes than the cell, a hypotonic solution has less. | | 56 |
| 6520906794 | water potential | the measure of potential energy in water ad describes how water flows, from an area of high water potential to an area of low water potential
it is affected by two factors: pressure potential and solute potential (formula to find SP is the picture) |  | 57 |
| 6520923216 | expand | A red blood cell dropped into a hypotonic solution (such as distilled water) will _______, because water will move into the cell, to an area of lower water potential. Eventually, the red blood cell will pop. | | 58 |
| 6520930737 | concentration | The _____ of a solution can be calculated by dividing the number of moles of solute by the volume (in liters) of a solution.
CiVi = CfVf | | 59 |
| 6520951553 | solutes | dissolved substances | | 60 |
| 6520953479 | facilitated diffusion | diffusion in which channel proteins pick up a substance from one side of the membrane and carry it across to the other; does NOT require energy |  | 61 |
| 6520969779 | active transport | movement against the natural flow; transport that REQUIRES energy
Suppose a substance wants to move in the opposite direction- from a region of lower concentration to a region of higher concentration. A transport protein can help usher the substance across the plasma membrane, but it's going to need energy to accomplish this. | | 62 |
| 6521077630 | sodium potassium pump | this special protein involved in active transport ushers out sodium ions and brings in potassium ions across the cell membrane
These pumps depend on ATP to get ions across the would otherwise remain in regions of higher concentration. These proteins are usually found in neurons and skeletal muscle fibers. |  | 63 |
| 6521092328 | endocytosis | the process in which the cell uses a portion of the cell membrane to engulf a large substance
The cell membrane forms a pocket, pinches in, and eventually forms either a vacuole or a vesicle. |  | 64 |
| 6521120119 | pinocytosis | type of endocytosis in which the cell ingests liquids ("cell-drinking") | | 65 |
| 6521124193 | phagocytosis | type of endocytosis in which the cell takes in solids ("cell-eating") | | 66 |
| 6521130469 | receptor mediated (endocytosis) | type of endocytosis in which a particle (ligand) binds to one of the cell surface receptors that are covered in clathrin-coated pits and is brought into the cell by the invagination or "folding in" of the cell membrane; a vesicle then forms around the incoming ligand and carries it into the cell's interior | | 67 |
| 6521149719 | bulk flow | the one-way movement of fluids brought about by pressure
For instance, the movement of blood through a blood vessel or movement of fluids in xylem and phloem of plants are examples of this process. | | 68 |
| 6521162617 | dialysis | the diffusion of solutes across a selectively permeable membrane
For example, a cellophane bag is often used as an artificial membrane to separate small molecules from large molecules. | | 69 |
| 6521169937 | exocytosis | process in which a cell ejects waste products or specific secretion products, such as hormones, by the fusion of a vesicle with the plasma membrane | | 70 |
| 6521179317 | intercellular junctions | when cells come in close contact with each other, they develop these that involve their plasma membranes as well as other components
These structures may allow neighboring cells to form strong connections with each other, prevent passage of materials, or establish rapid communication between adjacent cells. | | 71 |
| 6521323380 | desmosomes | these hold adjacent animal cells tightly to each other, like a rivet; they consist of a pair of discs associated with the plasma membrane of adjacent cells, plus the intercellular protein filaments that cross the small space between them |  | 72 |
| 6521335249 | gap junctions | protein complexes that form channels in membranes and allow communication between the cytoplasm of adjacent animal cells or the transfer of small molecules and ions |  | 73 |
| 6521351506 | tight junctions | membranes of neighboring cells are actually fused forming continuous belts around cell to prevent leakage of extracellular fluid |  | 74 |
| 6521358199 | quorum sensing | cell to cell chemical communication | | 75 |
| 6521362791 | taxis | the movement of an organism in response to a stimulus, and can be positive (towards the stimulus) or negative (away from the stimulus) | | 76 |
| 6521367067 | chemotaxis | a cellular movement in response to chemicals
Ex. ) Bacteria can control flagella rotation to direct their motion, thus avoiding repellents (such as poisons), or helping them find favorable locations with high concentrations of attractants (such as food). In our bodies, neutrophils use this to respond to an infection and are the first responders to inflammation. | | 77 |
| 6521382328 | signal transduction | process by which an external signal is transmitted to the inside of a cell
1. a signaling molecule binds to a specific receptor
2. activation of a signal transduction pathway
3. production of a cellular response | | 78 |
| 6521392996 | G protein linked receptor | this receptor doesn't act as an enzyme but transducer its signal to enzymes in the cytoplasm using a second messenger
One important second messenger is cyclic AMP. It is known as a "universal hunger signal" because it is the second messenger of the hormones epinephrine and glucagon, which cause energy mobilization. Second messengers are usually small molecules that can diffuse through the cell. They can be made and destroyed quickly and help the signal amplify throughout the cell. | | 79 |
| 6521411774 | catalytic receptor | receptor that has an enzymatic active site on the cytoplasmic side of the membrane
Enzyme activity is initiated by ligand binding at the extracellular surface. The insulin receptor is an example of an enzyme-linked receptor. After binding insulin, it initiates a complex signaling pathway that allows the cell to grow, synthesize lipids, and import glucose. | | 80 |
| 6521423255 | ligand gated ion channels | these channels in the plasma membrane open an ion channel upon binding a particular neurotransmitter
An example is the channel on the surface of a skeletal muscle cell at the neuromuscular junction. This channel opens in response to acetylcholine, and a massive influx of sodium depolarizes the muscle cell and causes it to contract. | | 81 |
