300936 Study Guide - Final Guide: Aromatic Amino Acids, Lipid Bilayer, Cell Membrane

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amberhare75

8 Nov 2018

School

UWS

Department

University of Western Sydney

Course

300936

Professor

unknown

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Document Summary

Describe the functions of the membrane as it pertains to its chemical elements e. g cell recognition, barrier function, signal transduction. Separates the (cid:272)o(cid:374)te(cid:374)ts of the (cid:272)ell fro(cid:373) its outside e(cid:374)(cid:448)iro(cid:374)(cid:373)e(cid:374)t a(cid:374)d it regulates what enters and exits the cell. Pla(cid:455)s a (cid:448)ital role i(cid:374) prote(cid:272)ti(cid:374)g the i(cid:374)tegrit(cid:455) of the i(cid:374)terior of the (cid:272)ell (cid:271)(cid:455) allo(cid:449)i(cid:374)g o(cid:374)l(cid:455) selected substances into the cell and keeping other substances out. It also ser(cid:448)es as a (cid:271)ase of atta(cid:272)h(cid:373)e(cid:374)t for the (cid:272)(cid:455)toskeleton in some organisms and the cell wall in others. Thus the cell membrane supports the cell and helps in maintaining the shape of the cell. The (cid:272)ell (cid:373)e(cid:373)(cid:271)ra(cid:374)e is pri(cid:373)aril(cid:455) (cid:272)o(cid:373)posed of protei(cid:374)s a(cid:374)d lipids. While lipids help to give membranes their flexibility and proteins monitor and maintain the cell"s chemical climate and assist in the transfer of molecules across the membrane. The lipid (cid:271)ila(cid:455)er is se(cid:373)i-permeable, which allows only selected molecules to diffuse across the membrane.

Related Questions

3. In an aqueous environment, the phospholipids of a membrane____.

a) are arranged in a single layer

b) are arranged in a bilayer with the polar heads of each layerlocated at the surface

c) are arranged in a bilayer with the fatty acid tails locatedat the surface

d) are arranged in a bilayer but the phospholipids have nospecific orientation

e) dissolve

4. which of the following molecules demonstrate dual solubilitycharacteristics

a) sterols only

b) proteins only

c) phospholipids only

d) sterols and phospholipids

e) sterols, phospholipids, and proteins

5. The "mosaic" part of the fluid mosaic model refers to themembrane ____.

a) proteins

b) phospholipids

c) cholesterol

d) functions

e) layers

9. Transport of a molecule across a cell membrane by facilitateddiffusion ____.

a) does not exhibit specificity for a particular type ofmolecule

b) requires the input of energy

c) depends on a concentration gradient

d) goes against the concentration gradient

e) allows non-polar uncharged molecules to diffuse across amembrane

13. A transport system in which transport of an ion in onedirection provides the energy for active transport in the oppositedirection is known as ____.

a) primary active transport

b) active diffusion

c) secondary active transport

d) cotransport

e) osmosis

14. Cells undergo exocytosis ____.

a) to pump protons down a concentration gradient

b) when replicating

c) to secrete protein and wastes from the cell

d) to ingest nutrients

e) as a means of cellular protection

15. What is the molecular basis of familialhypercholestremia?