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Cell Quiz
Chapters 7 and 8
102
Biology
11th Grade
11/08/2007

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Term
Organelles
Definition
Subcellular structures encased in a plasma membrane
Term
What do all cells have in common?
Definition
A plasma membrane, cytosol, chromosomes, and ribosomes.
Term
Differences between eukaryotes and prokaryotes
Definition
a. eukaryotes are bigger. b. eukaryotes have chromosomes in the nucleus while prokaryotes have them floating around in a nucleoid region, but nothing separates it from the rest of the cell. c. eukaryotes have organelles floating around in the cytoplasm, but prokaryotes have nothing.
Term
What limits the size of a cell?
Definition
Metabolic requirements. The surface area grows slower than the volume, and the plasma membrane can only take in so many nutrients and stuff at a time. When it can't supply itself with enough nutrients, it stops growing.
Term
Plasma membrane
Definition
A selective barrier which allows oxygen and other nutrients in and waste out. It encases the cell and the each organelle. The membrane participates in the cell's metabolism. It has a double layer of phospholipids, and interspersed with proteins.
Term
Nuclear envelope
Definition
A double membrane that surrounds the nucleus. The envelope is perforated with pores that reach down and fuse the inner and outer membranes. On each pore is an intricate protein structure called a "pore complex".
Term
Nuclear lamina
Definition
a netlike array of protein filaments that maintain the shape of the nucleus. The filaments stretch between the pores.
Term
Ribosomes
Definition
Particles made out of RNA and protein. They carry out protein synthesis (they make proteins). They come in two subunits.
Term
Free ribosomes
Definition
Suspended in the cytosol, these ribosomes make proteins all over the cell
Term
Bound ribosomes
Definition
Ribosomes attached to the outside of the endoplasmic reticulum. They make proteins that they insert into the membranes and either get put into the ER or get packaged and sent out to other organelles.
Term
Endomembrane system
Definition
Other membranes in eukaryotic cells. They are either in the system directly or in vesicles. They have no fixed molecular composition, metabolic behavior, or shape.
Term
Endoplasmic Reticulum (ER)
Definition
A membranous labyrinth that makes up half the Cisternae
Term
Smooth ER
Definition
ER without ribosomes. It has enzymes which are important to the synthesis of lipids, carbohydrate metabolism, and enzymes break down unusable products in the hydrolysis of glycogen. The enzymes also detoxify drugs and poisons by adding hydroxyl groups.
Term
Glycogen
Definition
Stores energy for carbohydrates
Term
Rough ER
Definition
Ribosomes make special proteins then enters the ER where they are attached to carbohydrates. Then they get transported out of the ER in membranes called transport vesicles. The transport vesicles later go to the golgi. Also, ER makes membranes with the secreted enzymes making phospholipids and the ribosomes make the proteins. These membranes are sent via transport vesicles
Term
Golgi apparatus
Definition
The golgi apparatus modifies, stores, and sends the products of the ER. It is made up of several stacked layers of cisternae. It has a cis end and a trans end. The cis end is the receiving end (receives vesicles) and the trans end is the sending end. The golgi enzymes modify the proteins from the ER (aka glycoproteins). It manufactures various macromolecules and moves others.
Term
Lysosomes
Definition
A digestive compartment that is membrane bounded. It is a sac of hydrolytic enzymes that can hydrolyze any macromolecule. It keeps at its ideal pH of 5 by pumping hydrogen constantly. It destroys the waste parts, and sometimes the whole cell.
Term
Food vacuoles
Definition
Vacuoles that fuse with the lysosome and help consume smaller organisms via phagocytosis
Term
Phagocytosis
Definition
When portists eat by engulfing other organisms
Term
Autophagy
Definition
When a cell recycles its own organic material. It takes the cytosol of an organelle it just destroyed and puts it in the cell's cytosol.
Term
Contractile vacuoles
Definition
What pump out excess water out of a cell
Term
Central vacuoles
Definition
Plants have this vacuole. It is enclosed by a membrane and it is used as a disposal for metabolic by-products. It also lets the cell become larger without lots of investment in cytoplasm.
Term
Tonoplast
Definition
The membrane that encloses the central vacuole.
Term
Mitochondria
Definition
Converts energy of a cell into energy that can be used for work. It is the site of cellular respiration. They are found in almost all eukaryotic cells. Sometimes a cell has one large one, a few big ones, or a bunch or small ones.
Term
Information on Mitochondria's Membrane
Definition
It has two membranes; an outermembrane which is normally shaped and smooth, and an intermembrane which is folded. This makes two mitochondrial compartments; the intermembrane space (between the two membranes) and the mitochondrial matrix (inside the inner membrane).
Term
Mitochondrial matrix
Definition
The mitochondrial compartment inside the membrane. It makes enzymes, and holds the DNA and the ribosomes.
Term
Cristae
Definition
The folds of the intermembrane of mitochondria.
Term
Cellular Respiration
Definition
A catabolic process that generates ATP by extracting it from sugars, fats, and other fuels with the help of oxygen.
Term
Chloroplasts
Definition
What plants use to convert energy to energy able to be used for work (via photosynthesis). They contain plastids, thylakoids, and stroma.
Term
Plastids
Definition
An organelle within chloroplasts. It has all the enzymes for photosynthesis and the chlorophyl (what makes the plants green).
Term
Thylakoids
Definition
Flattened sacs in the chloroplasts
Term
Granum
Definition
A pile of thylakoids
Term
Peroxisomes
Definition
A specialized metabolic comparment bound by a single membrane. It has enzymes that transfer hydrogen from various substrates to oxygen and use it to break down molecules. This is converted to water, and thus hydration occurs.
Term
Cytoskeleton
Definition
A network of fibers in the cytoplasm that organizes the structures within the cytoplasm. It anchors organelles and proteins, but can also be taken apart and remade in other parts of the cell. It also can regulate biochemical activities
Term
Cell motility
Definition
A cell's ability to move. This is controlled by the cytoskeleton (more specifically, the motor molecules within it.)
Term
Motor molecules
Definition
Proteins that bring about movement by letting molecules slide past each other.
Term
Main fibers in a cytoskeleton
Definition
Thickest to thinnest, microtubules, intermediate filaments, and microfilaments.
Term
Microtubules
Definition
Hollow tubes made up of a tubulin protein. They serve as a track for organelles to move on. They come in twos (together they are a centrosome, separately they are centrioles.) In each microtubule, there are nine centrosomes on the edge and one center centrosome. (9+2 pattern).
Term
Dynein
Definition
The arms that connect the centrosomes (doublets) and let them move as they do in cillia and flagella
Term
Basal bodies
Definition
What anchor the cillia/flagella to the cell
Term
Transport proteins
Definition
Proteins that span the membranes and let molecules that can't pass through the membrane pass through.
Term
Channel proteins
Definition
Proteins with a hydrophilic channel that allows certain molecules and ions through
Term
Aquaporins
Definition
Channel protein that allows the passage of water
Term
Carrier proteins
Definition
Proteins that bind to molecules and the change their shape to shuttle them across the membrane.
Term
Concentration gradient
Definition
The direction which a substance would want to diffuse.
Term
Passive transport
Definition
Transport of something into or out of a cell that does not use energy
Term
Active transport
Definition
Transport of something into or out of a cell that uses energy.
Term
Osmoregulation
Definition
The control of water balance in a cell to maintain its internal environment
Term
Facilitated Diffusion
Definition
Passive transport with the help of proteins
Term
Gated channels
Definition
Channels that open or close depending on the presence or absance of a chemical or physical stimulus.
Term
Sodium-potassium pump
Definition
A pump which changes shape with the addition and subtraction of a ATP phospholate group, and uses it to bring in K and take out Na.
Term
Cllia/Flagella
Definition
Microtubule that protrudes from the cell and moves the cell (like oars with cillia, and like a motor with flagella.)
Term
Microfilaments
Definition
They are made up of the actin protein. They support the cell's 3D shape by being around the boarder of the cytoplasm and making the outside gel like instead of fluid.
Term
Microfilament specific funtcions
Definition
a. Myosin, a thicker filament protein which "walks", moves against the actin and together they slide past each other so that contract the size of the cell or other contractions within the cell, which allows movement. b. Extends into pseudopodia which extend and contract to allow movement (especially in amoebas). c. cytoplasmic streaming, aka the circular flow of cytoplasm with the cell, is maintained by microfilaments
Term
Intermediate filaments
Definition
More permanent structures that reinforce the strength and the shape of a cell.
Term
Cell Wall
Definition
A wall around plant cells that maintains its shape and prevents excessive uptake of water.
Term
Layers of a cell wall
Definition
A thin and flexible wall called the primary cell wall is first. Then comes the middle lamella in between, a thin layer rich in polysaccharides called pectins. When it stops growing, this part of the cell wall becomes hard and strong. There is a secondary wall between the plasma membrane and the rest of the cell wall. It is the strong and durable wall.
Term
Collagen
Definition
The glycoprotein in most animal ECMs. They are strong fibers woven in a network of proteoglycans (another type of glycoprotein).
Term
Fibronectins
Definition
A glycoprotein used in an ECM which binds to receptor proteins called integrins, on the plasma membrane. They transmit changes in the ECM to the cytoskeleton so they can work together.
Term
Plasmodesmata
Definition
An open channel in a the cell wall of plants through which strands of cytosol connect to adjacent cells. Water and small solutes can pass between the two connected cells. Only for plants
Term
Animal cell junctions
Definition
Tight junctions, desmosomes, and gap junctions.
Term
Tight junctions
Definition
When membranes of neighboring cells are fused. No extracellular fluid gets in.
Term
Desmosomes
Definition
Also known as an anchoring junctions, cells are fastened together by strong intermediate filaments
Term
Gap junctions
Definition
Provide cytoplasmic channels between adjacent cells.
Term
Amphipathic
Definition
A molecule that has both a hydrophobic region and a hydrophilic region
Term
Fluid mosaic model
Definition
The membrane is a fluid structre with various proteins embedded and attached to the phospholipid bilayer
Term
How can phospholids move?
Definition
Drifting/switching laterally, or flip flopping vertically. The latter is rare because the hydrophilic side crosses the hydrophobic region and visa versa.
Term
What happens if the phospholipid bilayer isn't fluid enough?
Definition
The enzymatic proteins stop working and the lipid composition is altered
Term
Steroid Cholesterol
Definition
Wedged between phospholipids. Makes the membrane less fluid be restraining phospholipid movement. Also hinders close packing of molecules (lowers freezing temperature)
Term
Movement of proteins
Definition
They can, but not very quickly
Term
Transmembrane protein
Definition
A protein that completely spans the membrane.
Term
Peripheral proteins
Definition
Proteins not embedded in the lipid bilayer. Instead, they are appendages loosley bound to the surface of integral proteins
Term
Difference between internal and external faces of a membrane
Definition
They have different lipid compositions and protein orientations
Term
Functions of membrane proteins
Definition
Transport, enzymatic activity, signal transductions, intercellular joining, cell-cell recognition, attachment ot the cytoskeleton and ECM
Term
Membrane protein transport
Definition
a protein that spans the membrane can provide a hydrophilic channel down the middle that is selective to a paticular solute. It can also hydrolyze ATP as an energy source.
Term
Membrane protein enzymatic activity
Definition
A protein built into a membrane can be an enzyme with an active site exposed to tsubstances in the adjacent solution. It can even extend to a whole metabolic pathway.
Term
Membrane protein signal transduction
Definition
A membrane protein may have a binding protein may have a binding sight for a chemical messenger and then can realy messages to the cell.
Term
Membrane protein cell-cell recognition
Definition
Some glycoproteins serve as identificator of other proteins
Term
Membrane protein attachemnt to the cytoskeleton of ECM
Definition
Proteins can bond to microfilaments, which helps the cell maintain its shape.
Term
Membrane protein intercellular joining
Definition
Membrane proteins of adjacent cell can be hooked together via various junctions.
Term
Hypotonic
Definition
When there is a greater concentration of the solute inside the cell and less of the solute outside, filling it up
Term
Hypertonic
Definition
When there is a lesser concentraion of the solute inside the cell and more outside of the cell, thus making their less water in the cell
Term
Isotonic
Definition
When the concentration of the solute is even both inside and outside the cell
Term
Turgid
Definition
When a cell is filled with water (hypotonic)
Term
Flaccid
Definition
When a cell has no net net tendency for water to enter (isotonic)
Term
Plasmolyzed
Definition
When a cell has little water in it (hypertonic)
Term
Facilitated diffusion
Definition
When a polar molecule or ion diffues through the lipid bilayer with the help of transport proteins
Term
Cell-Cell recognition
Definition
The ability of a cell to distinguish one type of neighboring cell from another. This helps cells sort and organize and lets cells fight bad cells. It uses membrane carbohydrates branched from oligosaccharides. These oligosaccharides vary.
Term
Why are membranes inside and outside faces asymmetrical?
Definition
The membrane is made from materials (phosholipids, proteins, carbohydrates) in the ER, which is brought to the Golgi apparatus which adds stuff. Then it is transported by the vesicles to the inner layer. From the inner layer, it eventually goes to the outer layer, but still is sparadic in doing so.
Term
Membranes and permeability
Definition
Membranes control permeability; only smaller molecules can pass through. C02 is expuled and 02 is brought in. Mostly, the hydrophobic core decides. Proteins assist in regulating transport, including via transport proteins or channel proteins.
Term
Aquaporins
Definition
Channel proteins which allow water through
Term
Carrier Proteins
Definition
Proteins which bind to a molecule and change its shape so it can fit in.
Term
Concentraion gradient
Definition
A substance will diffuse to where it is less concentrated
Term
Diffusion
Definition
The tendency of moleucles of any substance to spread out into the available space
Term
Passive transport
Definition
Diffusion across a membrane. It is passive because it involves no energy
Term
Cotransport
Definition
When one solute going out indirectly makes another one go out (which usually couldn't). This is used to bring in macromolecules.
Term
Exocytosis
Definition
When a transport vesicle budded from the Golgi apparatus is moved by the cytoskeleton to the plasma membrane. When the membrane of the vesicle and the membrane of the Golgi apparatus come in contact, they fuse and spill the contents outside the cell.
Term
Endocytosis
Definition
When a cell brings in macromloecules by forming new vesicles in the plasma membrane. A small area of the membrane sinks inward, and eventually pinches off form going too deep to make a vesicle.
Term
Phagocytosis
Definition
When a cell engulfs another cell by extending psuedopodia around it and packaging it in a large vacuoule.
Term
Pinocytosis
Definition
When a vesicle is created around a drop of extracellular fluid.
Term
Receptor-mediated endocytosis
Definition
Ligands come it and bind to specifity transporting certain substances. This get triggered by a ligand. Bulk endocytosis allows a cell to get stuff it's low on.
Term
Ligands
Definition
Alloserics, but for binding receptors. They go onto the membrane surface, and only a certain protein or signal molecule can get in.
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