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156 Cards in this Set
- Front
- Back
ALL organisms are made of what? |
Cells. |
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The cell is the simplest/smallest collection of matter that is considered what? |
Alive. |
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ALL cells are related how? |
Through there descent from earlier cells. |
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Evolutionary changes take place how? |
Mutation of DNA. |
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Who was the first person to visualize and document cells through a microscope? |
Robert Hooke in 1665. |
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The first microscopes, and common laboratory microscopes are what? |
Light Microscopes, use light refraction to magnify images. |
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What is magnification? |
The ratio of an object's image size to it's real size. |
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What is resolution? |
A measure of clarity of an image. |
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What is contrast? |
The accentuation of differences in parts of an image. |
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What do Electron Microscopes allow us to view? |
At the organelle level and smaller. |
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How does an Electron Microscope work? |
Focuses a beam of electrons through or onto the sample. |
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What is an advanced version of the Electron Microscope which allows for the viewing of internal structures? |
Transmission Electron Microscope. |
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Why can't live cells be observed using a Electron Microscope? |
They are killed in the process of preparation. |
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What type of microscopy allows for viewing samples in 3D. |
Confocal and deconvolution microscopy. |
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What is cell fractionation? |
A method using a centrifuge to separate out cell components based on weight. |
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What is a pellet? |
Heavier organelles and/or components formed after centrifugation. |
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What is a supernatant? |
Liquid and other debris above the pellet. |
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How are different size particles separated out during centrfugation? |
By differing centrifuge speed and solvents containing the samples. |
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What are the two types of cells? |
1) Procaryotic (Bacteria and Archeae) 2) Eucaryotic (all other cells) |
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What is the plasma barrier? |
A bounding, selective barrier around all cells. |
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ALL cells have what that come in the form of DNA? |
Chromosomes. |
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Where does protein synthesis occur in ALMOST all cells? |
Ribosomes. |
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What is the major difference between eucaryotes and procaryotes? |
Where their DNA is stored. |
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Eucaryotic cells store their DNA where? |
In a double membrane bound organelle called the nucleus. |
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Procaryotic cells store their DNA where? |
In a non-membrane bound region known as a nucleoid because they have no nucleus. |
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What is cytoplasm? |
The entire interior of the cell minus the nucleus. |
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What type of cell is larger than the other? |
Eucaryotic > Procaryotic |
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Larger organisms do not have larger cells but? |
More of them. |
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What is the job of the selective barrier? |
Allowing passage for oxygen, nutrients, and wastes. |
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What are microvilli? |
Long thin projections extending out from the surface that increases the surface area of the cell without increasing too much volume. |
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What are the components of the cytoplasm? |
1) Cytosol 2) Organelle 3) Ion 4) Water 5) Proteins 6) Other biomolecules |
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Eucaryotic cell's genetic instructions are where? |
In the nucleus. |
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What carries out the genetic instructions in a Eukaryote? |
The ribosomes. |
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What is important about the nucleus? |
Contains most of the genes (in DNA/chromosomes). |
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What is the nuclear envelope? |
A double membrane enclosing the nucleus that separates the nucleus from the cytoplasm and is perforated by pore structures (nuclear pores). |
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What is the nuclear lamina? |
A network of protein filaments located on the nuclear side that maintains the shape of the nucleus. |
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What is a chromosome? |
Compact structure containing many proteins and one long DNA molecule. |
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How many chromosomes do humans have? |
46 |
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What is a chromatin? |
The complex proteins in a chromosome. |
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What is a nucleolus? |
A mass of dense granules in the nucleus where ribosomal RNA (rRNA) and proteins are combined to make ribosomes. |
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mRNA is made from what? |
DNA. |
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How does mRNA become a final protein product? |
Travels through nuclear pores to the rough endoplasmic reticulum where it is translated into a polypeptide and untimely a final protein product. |
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What are ribosomes? |
Large complexes/groupings that carry out protein synthesis and are made up of rRNA and proteins (protein factories). |
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What are free ribosomes? |
They circulate in the cytoplasm and are where protein synthesis starts due to the synthesizing of enzymes and proteins destined for the bound ribosomes. |
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What are bound ribosomes? |
They are attached to the endoplasmic reticulum. |
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What do bound ribosomes make? |
Proteins destined for: insertion unto membranes and packaging within organelles. |
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What does the endomembrane system regulate? |
Protein traffic and performs metabolic function. |
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What is the endomembrane system? |
The entire membrane system within cells. |
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What does the endomembrane system include? |
1) nuclear envelope 2) endoplasmic reticulum 3) Golgi apparatus 4) vesicles 5) plasma membrane |
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What are vesicles? |
Sacs/spheres made of membrane that travel amongst the endomembrane system. |
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What are transport vesicles? |
Vesicles in transit from one part of the cell to another. |
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What is the endoplasmic reticulum? |
An extensive network of membranes where protein synthesis can take place. |
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What is the cisternae? |
A network of membranous tubules and sacs in the endoplasmic reticulum. |
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What is a lumen? |
An internal compartment (cavity) or cisternae space in the endoplasmic reticulum. |
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Why are the endoplasmic reticulum and nucleus in close proximity to each other? |
Because the endoplasmic reticulum is continuous/attached to the nucleus. |
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What part of the endoplasmic reticulum lacks ribosomes? |
Smooth. |
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What part of the endoplasmic reticulum is studded with ribosomes? |
Rough. |
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What are the four functions of the smooth endoplasmic reticulum? |
1) synthesis of lipids 2) metabolism of carbohydrates 3) detoxification of drugs and poisons 4) storage of calcium |
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How does the rough endoplasmic reticulum function in protein synthesis? |
A polypeptide chain grows from a bound ribosome, it extends into the endoplasmic reticulum lumen where it begins the folding process. |
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What are glycoproteins? |
Secretory proteins that have carbohydrates covalently attached to them. |
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What is the function of the Golgi apparatus? |
It is the center for receiving, sorting, shipping, and some manufacturing of proteins. |
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What are the two sides of the Golgi apparatus? |
Cis side (receiving) and trans side (shipping). |
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What do budding transport vesicles do? |
Contain modified protein, leave from the trans side & travel to other parts of the cell or get excreted outside the cell. |
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What is a lysosome? |
A membranous sac of enzymes used to digest macromolecules (digestive compartments). |
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Where to lysosomes work best? |
In an acidic environment. |
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What is phagocytosis? |
The engulfing of smaller organisms or materials by surrounding them and consuming. |
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What forms from phagocytosis? |
Food vacuoles. |
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What is autophagy? |
The recycling of a cell's own materials. |
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What are vacuoles? |
Large vesicles that perform various functions and derive from the ER and Golgi (diverse maintenance compartments). |
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What is a contractile vacuole? |
Pumps excess water out of a protist cell. |
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What is a central vacuole? |
Contain the sap of a plant cell. |
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What do mitochondria and chloroplasts do? |
Transforms energy into energy that am organism can use. |
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What is cellular respiration? |
The metabolic process that converts sugars, fats, and oxygen into the energy molecule ATP. |
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What is mitochondria? |
The site of cellular respiration. |
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What is a chloroplast? |
The site of photosynthesis in plants and algae where solar energy is converted into chemical energy. |
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What is the Endosymbiont Theory? |
Mitochondria and chloroplasts share many similarities with bacteria. States that an early ancestor of eukaryotic cells engulfed an ancestral procaryote and set up a symbiotic relationship that eventually lead the the creation of mitochondria in one case and chloroplasts in another. |
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Evidence to support Endosymbiont Theory? |
1) they have a double membrane 2) they have their own ribosome and DNA 3) they seem to exist independently of the cell. |
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What is found in NEARLY all eukaryotic cells and number in the hundreds to thousands depending on the amount of cellular respiration occurring? |
Mitochondria. |
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What is mitochondria cistae? |
Infoldings (villi-like) found on the inner membrane of the mitochondria's double membrane. |
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What is the intermembrane space? |
First of two internal compartments found in mitochondria. |
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What is the mitochondrial matrix? |
Second internal compartment of the mitochondria containing enzymes, DNA, and ribosomes. |
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Where is cellular respiration carried out? |
In the mitochondrial matrix. |
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Chloroplasts are only found where and carry out what process? |
Plants, photosynthesis. |
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What is a thylakoid? |
A membranous system within the chloroplast consisting of flattened sacs. |
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What is a granum? |
A stack of thylakoid. |
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What is stroma? |
The fluid outside of the thylakoids. |
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What are the three parts of chloroplast? |
1) intermembrane space 2) stroma 3) thylakoid space |
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What are plastids? |
A family of closely related plant organelles. |
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What are the three plastids? |
1) chloroplast 2) amyloplast 3) chromoplast |
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What is an amyloplast? |
Colorless organelle that stores starch. |
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What are chromoplasts? |
Organelles containing pigments that give color. |
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What do Peroxisomes do? |
Transfers hydrogen atoms into oxygen to form hydrogen peroxide through the use of special enzymes. |
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What are Glyoxysomes? |
Specialized peroxisomes found in fat-storing tissues of plants. |
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What is the Cytoskeleton? |
A network of fibers throughout the cytoplasm that organizes structures and activities in the cell. |
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What are three main structures in the Cytoskeleton? |
1) Microtubules 2) Microfilamants 3) Intermediate Filaments |
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What is the role of the Cytoskeleton? |
Provides mechanical support to the cell wall and maintains its shape. |
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What is a cytoskeleton so important in animals? |
Because animals lack a strong cell wall. |
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What is cell motility? |
Aides in changes in cell location and more limited movements of parts of the cell. |
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What are motor proteins? |
Proteins attached to the cytoskeleton and use ATP to power movement. |
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How is movement generated? |
Proteins moving along the cytoskeletal fibers. |
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What cytoskeletal structure is the thickest? |
Microtubules. |
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What cytoskeletal structure is the thinnest? |
Microfilaments; also called actin filaments. |
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What is the size of intermediate filaments? |
Size of diameters is between microtubules and microfilaments. |
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What are the dimensions of hollow rods? |
25nm diameter and 200-25,000nm in length |
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What is a Tubulin? |
A globular protein composing the wall of microtubules. |
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Each tubulin protein consists of what? |
A alpha and beta tubulin. |
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Microtubules grow how? |
Adding tubulin dimers. |
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What do microtubules do? |
Guide secretory vesicles from the Golgi to the plasma membrane. |
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What are Centrosomes? |
Region located near the nucleus that organizes microtubules for chromosomal separation during mitosis |
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What are Centrioles? |
Found in pairs and are composed of 9 sets of triplet microtubules that help assemble and organize microtubules during mitosis. |
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What are flagella? |
Microtubule containing projections that allows for cell movement, limited to just a few per cell. |
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What are Cilia? |
Microtubule containing projections that allows for cell movement, usually number in the hundreds per cell. |
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What beating pattern do flagella and cilia use? |
"9+2" |
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What pattern in some cilia is considered nonmotile? |
"9+0" |
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What is the basal body? |
Anchors the microtubule to the cell wall. |
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What are Dyneins? |
Large motor proteins responsible for the bending movements of an organelle, utilizes ATP as their energy source. |
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What are microfilament diameters? |
Solid rods about 7nm diameter. |
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What is actin? |
A globular protein that is the building blocks for microfilaments. |
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What is the shape of a microfilament? |
A twisted double chain of actin subunits. |
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What is the purpose of microfilaments? |
To bear tension or pulling forces. |
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What is the Cortex? |
The outermost cytoplasmic layer of a cell. |
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What are Microvilli? |
Delicate projects on a cell surface made up of bundles of microfilaments. |
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What important role do microfilaments play in? |
Muscle contraction. |
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What is Myosin? |
Motor protein in muscle cells that walk along the bundles of microfilaments of the muscle tissue. |
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Contraction of muscle results from what? |
Actin and Myosin sliding past one another shortening the muscle. |
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What are Pseudopodia? |
Cellular extensions/projections that allow for the movement of organisms like the amoeba. |
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What is Cytoplasmic Streaming? |
The circular flow of the cytoplasm that speeds the distribution of materials within the cell. |
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What is the diameter of intermediate filaments? |
8-12nm |
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Intermediate filaments are related to microfilaments how? |
Specialized for bearing tension. |
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What are intermediate filaments constructed from? |
Keratins. |
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What can leave behind a network of intermediate filaments? |
Chemical treatments. |
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What major role does intermediate filaments play? |
Reinforcing cell shape and fixing the position of certain organelles. |
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What are axons reinforced by? |
Microfilaments. |
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What helps coordinate cellular activities? |
Extracellular components and connections between cells. |
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What is a Cell Wall? |
An extracellular structure of plant cells that distinguish them from animal cells. |
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What are the three functions of the cell wall? |
1) Protects the plant cell 2) Maintains the cell shape 3) Prevents excessive uptake of water |
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What is cellulose synthase? |
An enzyme that combines cellulose and microfibrils. |
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What is the Primary Cell Wall? |
Thin and flexible cell wall of young plants. |
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What is the Middle Lamella? |
A thin layer rich in sticky polysaccharides that forms between the primary walls of adjacent plant cells. |
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What is Pectin? |
Sticky polysaccharides of the middle lamella that glues adjacent cells together. |
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What is the Secondary Cell Wall? |
Deposited in several layers between the primary cell wall and the plant cell membrane. |
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What are the main components of Extracellular Matrix in animals? |
Glycoproteins and other carbohydrate containing molecules. |
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What is the most abundant glycoprotein in the ECM? |
Collagen. |
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What are two characteristics of collagen? |
They form strong fibers outside the cell and accounts for 40% of the total protein in the human body. |
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What do Proteoglycans do? |
Form the network or lattice of molecules in which collagen fibers get embedded to make a solid structure. |
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What is Fibronectin? |
Another glycoprotein (similar to protein) that attaches cells to the ECM. |
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What are Integrins? |
Cell-surface receptors that bind to the ECM and fibronectin. |
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What role does the Integrins have? |
Transmit signals between the ECM and cytoskeleton. |
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What are signaling pathways? |
Combination of mechanical and chemical signals. |
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What are Plasmodesmata? |
Membrane-lined channels filled with cytoplasm. |
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How to proteins reach the plasmodesmata? |
By moving along the fibers of the cytoskeleton. |
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What are cell junctions? |
Connection points between adjacent cells? |
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What are the three types of cell junctions? |
1) Tight junctions 2) Desmosomes 3) Gap junctions |
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What are Tight junctions? |
Portions of the plasma membrane of adjacent cells are tightly pressed against each other forming a continuous seals around the cell. |
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What are Desmosomes? |
Function like rivets; intermediate filaments made of keratin protein anchor desmosomes in the cytoplasm. |
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What are Gap junctions? |
Provide cytoplasmic channels to adjacent cells consisting of membrane proteins surrounding a pore. |