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28 Mar 2018

A transport system is a coupled, uniport - symport system. Which of the following is not true of this system?

a) it is a form of active transport

b) it uses energy to export and then recover a transport molecule

c) it has little specificity for ligands

d) it is a form of passive transport CloseSubmit

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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?

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

QUESTION 16

What is the function of tRNA molecules?

The A-P-E sites of the ribosome are made out of tRNA molecules

tRNAs transfer the ribosome onto the 5' cap of an mRNA molecule

tRNAs catalyze the formation of new peptide bonds

tRNAs form covalent bonds between the ribosome and the mRNA

tRNAs bring amino acids to specific codons

QUESTION 17

What's the difference between primary and secondary active transport?

Only primary active transport requires energy

Only in primary active transport does a solute move against its concentration gradient

Primary active transport can only move a single ion, while secondary transport moves two ions simultaneously

Primary transport is used for larger solutes, while secondary transport is used for smaller molecules

Primary transport uses ATP-powered pumps, while secondary transport uses energy indirectly

QUESTION 18

When do beta cells release insulin into your bloodstream?

		When you are very hungry
		When blood sugar levels are high
		When high levels of glycogen initiate the relase of insulin-containing vesicles
		When a G-coupled receptor on the beta cells binds to insulin
		When adrenaline binds to a beta cell receptor tyrosine kinase

1 Which of the following statements is false?

(a) CO₂ and O₂ can diffuse freely across the cell membranes.

(b) The differences in permeability between artificial lipid bilayers and cell membranes arise from variations in phospholipid content.

(d) Cells expend energy in the form of ATP hydrolysis to maintain ion concentrations that differ from those found outside the cell.

2 Cells use membranes to help maintain set ranges of ion concentrations inside and outside the cell. Which of the following ions is the most abundant inside a typical mammalian cell?

(a) Na⁺

(b) K⁺

(d) Cl^â

3 Pumps are transporters that are able to harness energy provided by other components in the cells and drive the movement of solutes across membranes, against their concentration gradient. This type of transport is called _____________.

(a) active transport.

(b) free diffusion.

(d) passive transport.