CAS BI 108 Study Guide - Final Guide: Active Transport, Lipid Bilayer, Passive Transport

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ivorybeetle196

8 Dec 2016

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The organization of these phospholipids creates a semi-permeability that allows for the membrane to choose what goes in and what comes out of the (cid:272)ell. Alo(cid:374)e, the phospholipid (cid:271)ila(cid:455)e(cid:396) allo(cid:449)s fo(cid:396) s(cid:373)alle(cid:396), (cid:862)fat solu(cid:271)le(cid:863) e(cid:374)tities to f(cid:396)eel(cid:455) pass i(cid:374) and out. These entities consist of small, nonpolar and uncharged molecules. These small uncharged molecules are able to surpass the hydrophobic interior of the phospholipid bilayer- successfully permeating into the cell. However, to account for the larger, polar and charged species that cells need for metabolic function, cells have developed a system of proteins that are non-covalently embedded into the bilayer. There are two types of proteins that present in the bilayer: integral proteins and peripheral proteins. Integral proteins contain hydrophobic regions that interact with the interior (nonpolar, hydrophobic) region of the bilayer, and hydrophilic regions that stretch extracellularly and can interact with various substances outside the cell.

Related Questions

Hybridomas are the useful result of a fusion between _______________ and _________________ to obtain hybrid cells that can proliferate and produce _________________ against specific ________________.

	myeloma cells; B lymphocytes; monoclonal antibodies; epitopes
	myeloma cells; T lymphocytes; polyclonal antibodies; antigen
	T lymphocytes; B lymphocytes; monoclonal antibodies; antigen
	T lymphocytes; B lymphocytes; polyclonal antibodies; epitopes

With respect to mammalian cell culture, which of the following statements is true?

	Media used for cell growth contain proteases and a divalent cation chelator to help cells adhere to the surface.
	During the establishment of a cell line, senescence is the last stage of the cell's life.
	Rodent cells cultures undergo spontaneous transformation with similar frequency to human cell cultures.
	Embryonic cell lines do not undergo senescence nor do they have a finite life span.

Epithelial cells have distinct surfaces. Which of these surfaces tends to be involved in secreting proteins out of the cell and into the bloodstream?

	apical
	basal
	All of the answers are correct.
	lateral

Which of the following is NOT true of phospholipid bilayers?

		Phospholipid bilayers separate the cell from the exterior environment as well as from compartments within the cell.
		The interior of phospholipid bilayers is a highly hydrophobic environment.
		Membrane budding requires transient breakages in the bilayer membrane.
		The chemical properties of phospholipids lead to the spontaneous formation of bilayers.

Which of the following is true regarding membrane proteins?

		All peripheral membrane proteins contact the lipid bilayer by covalent attachment to the hydrophilic head groups on membrane lipids.
		Beta strands can assemble into a membrane-spanning barrel structure.
		Lipid-anchored membrane proteins always face the cell exterior.
		A protein with six hydrophobic helices is most likely a lipid-anchored membrane protein.

Which of the following statements is NOT true?

		The three types of lipid anchors responsible for tethering proteins to the bilayer are acylation, prenylation, and ubiquitinylation.
		Movement of lipids from the cytoplasmic to the exoplasmic leaflet of the membrane bilayer requires specialized transport proteins called flippases.
		Glycoproteins are the basis for blood type compatibility between donor and receiver.
		Glycoproteins are always oriented so that the carbohydrate moieties are exoplasmic.

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?

a) HDL enters cells using a specific receptor on the cellsurface

b) LDL enters cells using a specific receptor on the cellsurface

c) HDL exits cells using a specific receptor on the cellsurface

d) LDL exits cells using a specific receptor on the cellsurface

e) receptor-mediated exocytosis

16. Carrier molecules are utilized for ____.

a) active transport only

b) passive transport only

c) both active and passive transport

d) osmosis

e) transport of all types of molecules

17. All of the following are functions of integral membraneproteins EXCEPT ____.

a) transport of polar molecules

b) reception of chemical signals form other cells

c) cell division

d) recognition of other cells as being "like"

e) cell-cell binding

olivecod348

To be alive, most cells must maintain a relatively constant internal enviornment. To do

this, they must be able to control the movement of materials into and out of the cell.

What characteristics of the cell membrane determine what get into the cell and what doesn't?

That is, what determines the permeability of a cell or organelle membrane? To answer these

questions, first consider the answer to the following questions:

f a cell membran were

composed of only a

phospholipid bilayer,

what properties would

it have?

Wha different roles or

functions do membrans

proteins serve?

Why are some cell types

more permeable to

a substance (for example,

sodium ions) than others?

Please answer in great detail please, thank you.

pucefox346

CAS BI 108 Study Guide - Final Guide: Active Transport, Lipid Bilayer, Passive Transport

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