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UConn Bio 1107 Exam 2 with correct
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ion channels - .... ๐ฐ VERIFIED ANSWERS.... โโ specialized channel proteins, circumvent the plasma membrane's impermeability to small, charged compounds such as Na+, Cl-, and K+ Gated channels - .... ๐ฐ VERIFIED ANSWERS.... โโ open or close in response to a stimulus, such as an electrical charge or chemical messenger electrochemical gradient - .... ๐ฐ VERIFIED ANSWERS.... โโ concentration gradient and a charge gradient how do electrochemical gradients occur? - .... ๐ฐ VERIFIED ANSWERS.... โโ when ions build up on one side of a plasma membrane chemiosmosis - .... ๐ฐ VERIFIED ANSWERS.... โโ process when ions diffuse thru channels down their electrochemical gradients, is a passive transport carrier proteins - .... ๐ฐ VERIFIED ANSWERS.... โโ transporters which change shape during the transport process
When does a transporter change shape? - .... ๐ฐ VERIFIED ANSWERS.... โโ when in contact with a substance in such a way that it shuttles the substance across the membrane translocate - .... ๐ฐ VERIFIED ANSWERS.... โโ to move a subtsance from one side of the membrane to the other side of the membrane What is active transport? - .... ๐ฐ VERIFIED ANSWERS.... โโ Transporting of molecules or ions against a concentration or electrochemical graident, requires enery in the form of ATP. Area of high concentration->low What are pumps? - .... ๐ฐ VERIFIED ANSWERS.... โโ Membrane proteins that provide active transport of molecules across the membrane ONLY FOR ACTIVE TRANSPORT- if you see pump its active transport What does active transport allow? - .... ๐ฐ VERIFIED ANSWERS.... โโ cells to maintain internal concentrations of small solutes that differ from concentrations in the external environment, and vice versa Sodium-pastassium pump (Na+/K+-ATPase) uses - .... ๐ฐ VERIFIED ANSWERS.... โโ ATP to transport Na+ and K+ against their concetration gradeints to maintain these concetration differences
water across a plasma membrane is called osmosis, movement of solutes is dialysis Differences in solute concentrations between the inside and outside of a cell will affect the process of osmosis and the cell's tone. In cells, membrane proteins are responsible for the passage of insoluble substances that can't cross the membrane on their own. Channel and carrier proteins aid in passive transport via facilitated diffusion. Pumps aid in active transport, requiring energy to move molecules/ions against their concentration gradient. This energy comes from ATP or an electrochemical gradient, such as with cotransporters in secondary active transport. - .... ๐ฐ VERIFIED ANSWERS.... โโ T or F: unicellular organisms connect to one another - .... ๐ฐ VERIFIED ANSWERS.... โโ False What forms mutlicellularity? - .... ๐ฐ VERIFIED ANSWERS.... โโ physical connections between cells cell-cell connections:Plants - .... ๐ฐ VERIFIED ANSWERS.... โโ glued together by middle lamella continuous with the primary cell walls of adjacent plant cells
What are middle lamella composed of? - .... ๐ฐ VERIFIED ANSWERS.... โโ Gelatinous pectins-polysaccharides like jams or jellies cell-cell connectiions: animals - .... ๐ฐ VERIFIED ANSWERS.... โโ extracellular matrix-surrounds cell membrane, contains polysacchrides reinforced by cable-like proteins Can be held together by two main types of cell junctions: tight junctions, demosomes. Especially common in epitehlial tissue Connections in extracellular matrix - .... ๐ฐ VERIFIED ANSWERS.... โโ Functions: Structural support, froms protein-protein attacthment which will link the ECM to the cell's cytoskeleton to protect against tension and compression What is the most coimon ECM protein fiber? - .... ๐ฐ VERIFIED ANSWERS.... โโ Collagen- it is more elastic than cellulose and peptioglycan(found in cell walls of plants/bacteria) Tight Junctions - .... ๐ฐ VERIFIED ANSWERS.... โโ Establish a water-tight barrier, cell-cell adhesions composed of specailized proteins in the plasma membranes of adjacent animal cells
they are like plasmodesmta but are composed of membrane transport proteins what does cell signaling allow? - .... ๐ฐ VERIFIED ANSWERS.... โโ For complex communcation system that can control basic cellular activities in cells(proteins synthesis, activating/deactivating chemical reactions) , and coordinate cellular actives across multiple cells(cell division and differentiation) where do the cell signals come from? - .... ๐ฐ VERIFIED ANSWERS.... โโ From other cells, or changes in the physical environment, such as light and touch how do most cells communicate with eachother? - .... ๐ฐ VERIFIED ANSWERS.... โโ chemical signals, can be either local or long distance What is quorum sensing? - .... ๐ฐ VERIFIED ANSWERS.... โโ cell- cell communication in bacteria(prokaryotes) bacteria release a species specific signaling molecules when there is acertain number of bacteria in an environment allows bacterial populations to carry out activities that are only producitive when performed by a critical mass of cells in synchrony
local signaling-how? - .... ๐ฐ VERIFIED ANSWERS.... โโ Cell-cell gaps(plasmodesmata in plans, and gap junctions in animals) cell-cell recognition, which involves direct contact between membrane molecules-glycoprotein tags can be recognized by membrane receptor proteins What are local regulators? - .... ๐ฐ VERIFIED ANSWERS.... โโ messnger molecules that are secreted by signaling cells and only travel short distance, in animals cells local signaling involving regulators is called PARACRINE SIGNALING How do long distant cells communicate? - .... ๐ฐ VERIFIED ANSWERS.... โโ -Horomones are long distance-messenger -infomration carrying molecules -usually small -typically present in minute concentration -can have large impact on condition of the organism as a whole- Hormones are long distance messengers - .... ๐ฐ VERIFIED ANSWERS.... โโ in animal is known as endocrine signaling Pathway of endocrine signaling - .... ๐ฐ VERIFIED ANSWERS.... โโ Hormone is secreted from an endocrine cells -circulates in body via circulatory system -horomes acts on target cellls far from signaling cell
typically proteins that change shap or activity after they bind to singaling molecule dynamic and may change senstivity to particlar hormones can be block as a way of regulating pathway What are membrane receptors? - .... ๐ฐ VERIFIED ANSWERS.... โโ signal receptors that bind to lipid-insoluble hormones are located in the plasma membrane what are intracellular receptors? - .... ๐ฐ VERIFIED ANSWERS.... โโ signal receptors that bind to lipid-soluble horomes (inside cell) T or F: some signaling molecules are small enough that they can pass thru the membrane even if they are NOT lipid-soluble - .... ๐ฐ VERIFIED ANSWERS.... โโ True(nitric oxide, NO) What do lipid-soluble hormones bind to inside the cell and waht does it form? - .... ๐ฐ VERIFIED ANSWERS.... โโ binds to the intracellular receptrs and forms a hormone-receptor complex What is a transcription factor? - .... ๐ฐ VERIFIED ANSWERS.... โโ is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence.
What do lipid-insoluble hormones bind to? - .... ๐ฐ VERIFIED ANSWERS.... โโ membrane receptors What is a signal transduction pathway? - .... ๐ฐ VERIFIED ANSWERS.... โโ extracellular hormone signal is converted to an intracellular signal is passed along by relay molecules until a response is triggered Where does signal transudction occur? - .... ๐ฐ VERIFIED ANSWERS.... โโ The plasma membrane Where does signal amplification occur? - .... ๐ฐ VERIFIED ANSWERS.... โโ inside the cell what is protein kinase? - .... ๐ฐ VERIFIED ANSWERS.... โโ type of enzyme that adds a phosphate group to other proteins Whats the process of phospholoryation cascades? - .... ๐ฐ VERIFIED ANSWERS.... โโ the a PK is phoshorylated it changes shape, the activates the next protein kinase, chain reaction When do protein kinsases become inactive? - .... ๐ฐ VERIFIED ANSWERS.... โโ when the proptein phosphatase removes the attacthced phosphate Whatis fine-tuning? - .... ๐ฐ VERIFIED ANSWERS.... โโ mutli-step pathways that are involved in signal transduction provide more opportunities for regulation and coordination with other pathways which allows fine-tuning of resposonses
Hormone interacts with an internal receptor protein and together directly trigger a change in the cell - such as protein synthesis Lipid-insoluble hormones - .... ๐ฐ VERIFIED ANSWERS.... โโ Typically peptide hormones (e.g. insulin) Large and hydrophilic and cannot cross the cell membrane (lipid- insoluble) Require attachment to membrane receptor proteins and "transduction" of signal into cell Results in similar cell responses as with lipid-soluble hormones but signal is indirect and can be amplified Pathways are more easily fine-tuned
