Amy Arce
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Amy Arce
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Ch 12

Question 1 of 60

1

Membrane characteristics

Select one or more of the following:

  • Sheet like structures, two molecules thick, form closed boundaries

  • composed of lipids and proteins,

  • noncovalent assemblies

  • covalent assesmblies

  • are fluid structures

  • are fatty structures

  • Most are electrically polarized

Explanation

Question 2 of 60

1

Membranes are asymmetric in that the outer surface is always different from the inner surface

Select one of the following:

  • True
  • False

Explanation

Question 3 of 60

1

Membrane lipids are

Select one of the following:

  • small amphipathic molecules that form closed bimolecular sheets that prevent the movement of polar or charged molecules.

  • large amphipathic molecules that form closed bimolecular sheets that prevent the movement of polar or charged molecules.

  • small amphipathic molecules that form closed molecular sheets that prevent the movement of polar or charged molecules.

  • large amphipathic molecules that form closed molecular sheets that prevent the movement of polar or charged molecules.

Explanation

Question 4 of 60

1

Proteins serve to mitigate the impermeability of membranes and

Select one of the following:

  • allow movement of molecules and information across the cell membrane

  • don't allow movement of molecules and information across the cell membrane

Explanation

Question 5 of 60

1

Fatty acid names are based on their parent hydrocarbons

Select one of the following:

  • True
  • False

Explanation

Question 6 of 60

1

Fatty acids

Select one or more of the following:

  • are chains of hydrogen bearing carbon atoms that have a carboxylic acid at one end and a methyl group at the other end

  • are chains of hydrogen bearing carbon atoms that have a ketone at one end and a methyl group at the other end

  • may be saturated or unsaturated

  • usually numbered beginning with the carboxyl terminal carbon atom

  • When double bonds present, they are commonly in the cis position

  • Properties are dependent on chain length and degree of unsaturation

Explanation

Question 7 of 60

1

Fatty acids can also be numbered from the methyl carbon atom which is called the omega (ω) carbon.

Select one of the following:

  • True
  • False

Explanation

Question 8 of 60

1

Fill the blank spaces to complete the text.

Carbon atoms and are also referred to as α and β, respectively.

Explanation

Question 9 of 60

1

Select from the dropdown lists to complete the text.

Fatty acids in biological systems usually contain an ( even, odd ) number of carbon atoms, with the ( 16, 15 )- and ( 18, 17 )-carbon atom chains the most common.

Explanation

Question 10 of 60

1

In polyunsaturated fatty acids, the double bonds are separated by at least one

Select one of the following:

  • methylene group

  • carboxylic acid

  • ketone

  • aldehyde

Explanation

Question 11 of 60

1

Long chain length and the presence of cis double bonds enhances the fluidity of fatty acids

Select one of the following:

  • True
  • False

Explanation

Question 12 of 60

1

What are the major class of membrane lipids

Select one of the following:

  • Phospholipids

  • Glycolipids

  • Cholesterol

Explanation

Question 13 of 60

1

Phospholipids are composed of four components:

Select one of the following:

  • fatty acids (1 or more), a platform, a carbon, and an alcohol.

  • fatty acids (1 or more), a platform, a phosphate, and an alcohol.

  • fatty acids (1 or more), a platform, a phosphate, and an nitrogen.

Explanation

Question 14 of 60

1

Select from the dropdown lists to complete the text.

Two common platforms are ( glycerol, glycogen ) and ( sphingosine, sphinose )

Explanation

Question 15 of 60

1

Phospholipids with a glycerol platform are called

Select one or more of the following:

  • phosphoglycerides

  • phosphoglycerols

  • phosphoglycogen

Explanation

Question 16 of 60

1

The common types of membrane lipids are

Select one or more of the following:

  • Phospholipids

  • Glycolipids

  • Cholesterol

  • Carbohydrates

Explanation

Question 17 of 60

1

The major phospholipids are derived from

Select one of the following:

  • Phosphatidate (diacylglycerol 3-phosphate)

  • Phosphatidate (diacylglycerol 2-phosphate)

Explanation

Question 18 of 60

1

Phosphoglycerides are derived from phosphatidate by the formation of an ester bond between the phosphate and an alcohol

Select one of the following:

  • True
  • False

Explanation

Question 19 of 60

1

Glycolipids are

Select one or more of the following:

  • carbohydrate-containing lipids derived from sphingosine.

  • carbohydrate-containing lipids derived from glycerol.

Explanation

Question 20 of 60

1

The carbohydrate in the glycolipid is linked to the secondary alcohol of sphingosine

Select one of the following:

  • True
  • False

Explanation

Question 21 of 60

1

What are the simplest glycolipids, containing only a single sugar

Select one of the following:

  • Cerebrosides

  • Gangliosides

  • Monosaccharides

Explanation

Question 22 of 60

1

Gangliosides contain a branched chain of as many as

Select one of the following:

  • seven sugar molecules

  • five sugar molecules

  • three sugar molecules

  • eight sugar molecules

Explanation

Question 23 of 60

1

Select from the dropdown lists to complete the text.

The ( carbohydrate, lipid ) components of glycolipids are on the ( extracellular, intracellular ) surface of the cell membrane, where they play a role in cell-cell recognition

Explanation

Question 24 of 60

1

Cholesterol is a lipid based on a steroid nucleus

Select one of the following:

  • True
  • False

Explanation

Question 25 of 60

1

Cholesterol is a

Select one of the following:

  • a steroid that is modified on both ends by the attachment of a fatty acid chain and at the other end by a methyl group

  • a steroid that is modified on one end by the attachment of a fatty acid chain and at the other end by a hydroxyl group

Explanation

Question 26 of 60

1

In membranes, the hydroxyl group interacts with phospholipid head groups

Select one of the following:

  • True
  • False

Explanation

Question 27 of 60

1

A membrane lipids is an

Select one of the following:

  • an amphipathic molecule containing a hydrophilic and hydrophobic moiety

  • an amphipathic molecule containing a hydrophilic moiety

  • an amphipathic molecule containing a hydrophobic moiety

Explanation

Question 28 of 60

1

The fatty acid components provide the

Select one of the following:

  • hydrophobic properties

  • hydrophilic properties

Explanation

Question 29 of 60

1

The alcohol and phosphate components are called the

Select one of the following:

  • polar head group, hydrophilic properties

  • polar head groups, hydrophobic properties

Explanation

Question 30 of 60

1

Phospholipids and Glycolipids Readily form Bimolecular sheets in Aqueous Media

Select one of the following:

  • True
  • False

Explanation

Question 31 of 60

1

Membrane formation is a consequence of the amphipathic nature of the constituent lipid molecules.

Select one of the following:

  • True
  • False

Explanation

Question 32 of 60

1

Phospholipids are

Select one or more of the following:

  • too large to form micelles

  • too small to form micelles

  • like glycolipids spontaneously form lipid bilayers in aqueous solutions

  • like glycolipids nonspontaneously form lipid bilayers in aqueous solutions

Explanation

Question 33 of 60

1

Select from the dropdown list to complete the text.

The hydrophobic effect powers membrane formation, and van der Waals interactions between the ( hydrophobic, hydrophillic ) tails stabilize membranes

Explanation

Question 34 of 60

1

Integral membrane proteins

Select one of the following:

  • composed of β strands that form a pore in the membrane.

  • composed of α helices that form a pore in the membrane

Explanation

Question 35 of 60

1

What is an example of β strand–rich integral membrane protein.

Select one of the following:

  • bacterial protein porin

  • Membrane spanning

Explanation

Question 36 of 60

1

Select from the dropdown lists to complete the text.

The ( outside, inside ) surface of porin, which interacts with the ( hydrophobic, hydrophillic ) interior of the membrane, is composed of ( hydrophobic, hydrophillic ) amino acids. The ( inside, outside ) is ( polar, nonpolar ) and filled with water.

Explanation

Question 37 of 60

1

Membrane-spanning α helices are a common structural feature of integral membrane proteins.

Select one of the following:

  • True
  • False

Explanation

Question 38 of 60

1

Bacteriorhodopsin, a light-powered proton pump, is an integral membrane protein composed of eight membrane- spanning helices.

Select one of the following:

  • True
  • False

Explanation

Question 39 of 60

1

Only a portion of the enzyme prostaglandin H2 synthase-1 is embedded in the membrane.

Select one of the following:

  • True
  • False

Explanation

Question 40 of 60

1

Select from the dropdown list to complete the text.

The cyclooxygenase (COX) activity of prostaglandin H2 synthase-1 is dependent on a channel connecting the ( active site, terminator site ) to the membrane interior.

Explanation

Question 41 of 60

1

What inhibits cyclooxygenase activity by obstructing the channel

Select one of the following:

  • Aspirin

  • Xanax

  • Klonopin

  • Naproxen

Explanation

Question 42 of 60

1

Hydrophobic proteins can be made to associate with the membrane by attaching a hydrophillic group.

Select one of the following:

  • True
  • False

Explanation

Question 43 of 60

1

The fluid mosaic model allows

Select one of the following:

  • lateral movement but not rotation through the membrane

  • rotation through the membrane

  • vertical movement

Explanation

Question 44 of 60

1

The fluid mosaic model describes

Select one of the following:

  • membranes as two-dimensional solutions of oriented lipids and globular proteins

  • membranes as two-dimensional solutions of oriented lipids and quartnary proteins

  • membranes as two-dimensional solutions of oriented lipids and primary proteins

Explanation

Question 45 of 60

1

The lipids serve as a solvent and a permeability barrier

Select one of the following:

  • True
  • False

Explanation

Question 46 of 60

1

Lipids rapidly diffuse vertically in membranes, although transverse diffusion or flip-flopping is very rare without the assistance of enzymes

Select one of the following:

  • True
  • False

Explanation

Question 47 of 60

1

Fill the blank space to complete the text.

The prohibition of diffusion accounts for the stability of membrane asymmetry.

Explanation

Question 48 of 60

1

Membrane fluidity is controlled

Select one of the following:

  • by fatty acid composition and carbohydrate content

  • by fatty acid composition and cholesterol content

  • by fatty acid composition and amino acid content

Explanation

Question 49 of 60

1

Cholesterol helps to maintain proper membrane fluidity in membranes in animals

Select one of the following:

  • True
  • False

Explanation

Question 50 of 60

1

No Biological membranes are asymmetric

Select one of the following:

  • True
  • False

Explanation

Question 51 of 60

1

The Na+-K+ pump illustrates

Select one or more of the following:

  • the principle of membrane asymmetry.

  • Pumps 3 Na+ out of the cell and 2 K+ into the cell by hydrolyzing ATP on the intracellular side of the membrane

  • Pumps 2 Na+ out of the cell and 3 K+ into the cell by hydrolyzing ATP on the extracellular side of the membrane

Explanation

Question 52 of 60

1

Some bacteria are enclosed by a single membrane surrounded by a cell wall.

Select one of the following:

  • True
  • False

Explanation

Question 53 of 60

1

Other bacteria are surrounded by two membranes, with a cell wall lying between them

Select one of the following:

  • True
  • False

Explanation

Question 54 of 60

1

Other bacteria are surrounded by two membranes, with a cell wall lying between them.The space between the two membranes is called the

Select one of the following:

  • periplasm

  • cytoplasm

  • mitochondria

Explanation

Question 55 of 60

1

With exception of plants, what cells do not have cell walls and area surrounded by a single membrane, the plasma membrane

Select one of the following:

  • Eukaryotic cells

  • Prokaryotic cells

Explanation

Question 56 of 60

1

Cells can acquire molecules from their environment by receptor-mediated endocytosis.

Select one of the following:

  • True
  • False

Explanation

Question 57 of 60

1

The protein clathin helps to

Select one of the following:

  • internalize receptors bound to their cargo

  • receptor-mediated endocytosis

  • facilitate membrane fusion by forming tightly coiled four-helical bundles

Explanation

Question 58 of 60

1

Select from the dropdown lists to complete the text.

Fusion of internal membranes with the plasma membrane allows the ( release, absorabance ) of molecules, such as ( neurotransmitters, serotonin ), from the cell

Explanation

Question 59 of 60

1

9. The internalization of iron-bound transferrin in association with the transferrin receptor is a example of

Select one of the following:

  • SNARE proteins

  • receptor-mediated endocytosis

  • protein clathrin

Explanation

Question 60 of 60

1

Fill the blank space to complete the text.

proteins facilitate membrane fusion by forming tightly coiled four-helical bundles.

Explanation

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