Bio Chemistry Test Two Review

Front 1

A fatty acid designated as 20:0 is ________, while one that is designated 20:3 D5,8,11 is ________.

Back 1

saturated; unsaturated

Hint 1

See Lecture Notes Asap

A fatty acid designated as 20:0 is saturated, while one that is designated 20:3 D5,8,11 is unsaturated.

Front 2

A fatty acid designated w-3

Back 2

has a double bond three carbons from the end of the chain.

Front 3

As temperatures grow colder with the onset of winter, animals will adapt by changing the fatty acid composition of cell membranes. What characteristics of fatty acids will be seen?

Back 3

shorter chains with greater unsaturation

Front 4

Cellulose is indigestible to most animals because

Back 4

animals do not have the enzymes needed to hydrolyze the β-glycosidic linkages between the monomer units

Front 5

The carbohydrate shown is a?

Back 5

a Monosaccharide

a Ketose

and

a Hexose

Front 6

What type of linkage is bond #3?

Back 6

Alpha 2,4 linkage

α[2,4]

Front 7

Which protein would likely be involved in a channel?

Back 7

Protein one

Hint 7

Proteins (transport) extend from the exterior of the bilayer to the interior of the cell

Front 8

Facilitated diffusion (passive transport) through a biological membrane is

Back 8

driven by a concentration gradient.

Front 9

Glycolipids are characterized by containing the following non-lipid component:

Back 9

Sugars

Front 10

How does the presence of cis double bonds in fatty acids affect membrane fluidity?

Back 10

They tend to increase the fluidity.

Front 11

How many hydroxyl groups does a molecule of glycerol have?

Back 11

three

Hint 11

Front 12

Humans are not able to digest cellulose as a food source because:

Back 12

Cellulose is insoluble and we lack the enzyme to break the β linkage in the cellulose.

Front 13

If the concentration of a solute is the same both inside and outside the cell, what might you expect with regard to its transport by a membrane protein?

Back 13

Movement of the solute across the membrane could occur and cause accumulation on one side of the membrane by an active transport protein.

Front 14

In the sodium-potassium pump

Back 14

sodium is transported out of the cell and potassium into the cell, both against concentration gradients

Front 15

Lactose intolerance

Back 15

arises from inability to metabolize the disaccharide lactose

Front 16

Membrane lipids in a lipid bilayer are held together by

Back 16

hydrophobic interactions

Front 17

Membranes are generally symmetrical, i.e., the outer face is composed of the same number and types of phospholipids as the inner face.

Back 17

False

Front 18

Rank the melting points of the following fatty acids from highest to lowest:

Back 18

Steraic Acid

Palmitic Acid

Trans-oleic Acid

Cis-oleic Acid

Linoleic Acid

4 is > 5

5 is > 2

2 is > 1

1 is > 3

Front 19

Receptors are often invaginated into the cell after binding to their specific molecule.

Back 19

True

Front 20

Secondary active transport involves the conversion of ATP to ADP.

Back 20

False

Front 21

Sucrose is composed of the following simple sugars:

Back 21

glucose and fructose

Front 22

The Sodium, Potasium-ATPase is a(n) _____ that moves Sodium from _____ and patasium from _____.

Back 22

antiporter; inside to out; outside to in

Hint 22

The Na,K-ATPase is a(n) antiporter that moves Na+ from inside to out and K+ from outside to in.

Front 23

The association of membrane proteins with lipids in the membrane bilayer always involves

Back 23

hydrophobic interactions

Front 24

the chemical name for table sugar is ________ and it is a ________.

Back 24

sucrose; disaccharide

Hint 24

the chemical name for table sugar is sucrose and it is a disaccharide

Front 25

Alpha 1,4 glycosidic linkage

Back 25

Hint 25

Look at Protons on 1,4 carbons

Front 26

Beta 1,4 glycosidic linkage

Back 26

Hint 26

Look at protons on 1,4 carbons

Front 27

Alpha 1,2 linkage

Back 27

Hint 27

Look at ring structures

Look at 1,2 carbons

Front 28

Alpha 1,6 glycosidic linkage

Back 28

Hint 28

Look at binding carbons.

Front 29

The degree of membrane fluidity depends on

Back 29

the percentage of unsaturated fatty acids

Front 30

The difference between active transport and passive transport is that

Back 30

one requires expenditure of energy by the cell and the other does not.

Front 31

The mechanism of membrane transport may involve the following:

Back 31

ATP hydrolysis.

Conformation change of membrane proteins.

Phosphorylation or dephosphorylation of membrane proteins.

ATP hydrolysis and conformation change of membrane proteins.

Front 32

The membrane-spanning portion of a transmembrane protein is almost always a -strand.

Back 32

False

Front 33

The most common biopolymer on earth is this carbohydrate:

Back 33

Cellulose

Front 34

The simplest keto-triose is

Back 34

dihydroxyacetone.

Front 35

Trans fatty acids have physical properties like those of

Back 35

saturated fatty acids.

Front 36

Transport of a compound across a cell membrane (down a concentration gradient) was measured at several concentrations. The presence or absence of ATP had no effect on the transport of this compound. Which best describes the mechanism of transport?

Back 36

facilitated diffusion

Hint 36

See Lecture Notes Asap

Front 37

Transport of glucose from the intestine into the intestinal cells is accomplished by a(n) ________. This is an example of ___________.

Back 37

symporter; secondary active transport

Hint 37

Transport of glucose from the intestine into the intestinal cells is accomplished by a(n) symporter. This is an example of secondary active transport.

Front 38

Triacylglycerols cannot form lipid bilayers because they

Back 38

do not have polar heads.

Front 39

Triacylglycerols may have either a net positive charge or a net negative charge.

Back 39

False

Front 40

Unsaturated fatty acids usually have ____ double bonds.

Back 40

cis

Front 41

Unsaturated fatty acids:

Back 41

are commonly found in plants and animals

usually contain a double bond with cis stereochemistry

sometimes contain multiple double bonds

have lower melting points than the analogous saturated fatty acids

Front 42

What are the characteristics of most unsaturated fatty acids found within a human cell?

Back 42

deprotonated carboxylic acid and cis double bonds

Front 43

What distinguishes primary from secondary active transport?

Back 43

The linkage to ATP hydrolysis

Front 44

What does amphipathic mean?

Back 44

having both hydrophilic and hydrophobic regions

Front 45

What is a transporter that moves two different molecules or ions in the same direction?

Back 45

symporter

Front 46

What is the role of cholesterol in animal cell membranes?

Back 46

Broadens the temperature range of optimum membrane fluidity.

Front 47

What kinds of bonds do lipase break in order to release fatty acids from triacylglycerols?

Back 47

esters

Front 48

What type of bond links the monomers of a polysaccharide?

Back 48

Correct glycosidic bond

Front 49

When a membrane reaches its transition temperature, integral membrane proteins dissociate from the bilayer.

Back 49

False

Front 50

When a membrane reaches its transition temperature, phospholipids readily flip from one face to the other.

Back 50

False

Front 51

Which is not a similarity between active transport proteins and enzymes?

Back 51

Both cause chemical modification to the substrate.

Hint 51

Enzymes do not change the substrate

Front 52

Which of the following best describes lipids' insolubility in water?

Back 52

They are typically insoluble.

Front 53

Which of the following best describes the glycosidic bond in the disaccharide shown?

Back 53

Alpha 2,4

α(2−4)

Front 54

Which of the following four fatty acids has the highest melting point?

Back 54

2

Front 55

Which of the following four fatty acids has the lowest melting point?

Back 55

4

Front 56

The presence of trans double bonds is not a characteristic of most fatty acids.

Back 56

the presence of trans double bonds is not a characteristic of most fatty acids.

Front 57

Which of the following is true about membrane proteins embedded within the lipid bilayer?

Back 57

As the temperature decreases, lateral diffusion of the membrane protein is restricted in bilayers with lipids which have longer chain fatty acids and fewer double bonds.

Front 58

Asymetric Membranes do not

Back 58

transverse diffusion occurs very quickly

lateral diffusion occurs very slowly

a flippase causes lateral diffusion to occur very rapidly

carbohydrates attached to membrane lipids are usually found on the cytosolic side of the membrane

Front 59

Which of the following lipids is not found in biological membranes?

Back 59

triacylglycerols

Front 60

Which of the following methods of transport across a membrane does not require a protein?

Back 60

Simple diffusion

Front 61

Which of the following molecules is a disaccharide?

Back 61

lactose

Front 62

Which of the following molecules is not amphipathic?

Back 62

glucose

Front 63

Which of the following monosaccharides is a ketose?

Back 63

fructose

Front 64

Which of the following statements associated with cellulose is false?v

Back 64

Most animals can easily digest this compound.

Front 65

Which of the following statements concerning active transport is true?

Back 65

A membrane-associate protein must be involved

Front 66

Which of the following statements describes integral membrane proteins?

Back 66

amino acids that contact the core of the membrane are hydrophobic

Front 67

fatty acids in both triacylglycerols and in phosphoacylglycerols vary.

Back 67

fatty acids in both triacylglycerols and in phosphoacylglycerols vary.

Front 68

Which of the strucures below is an example of a w-3 polyunsaturated fatty acid

Back 68

Structure B

Front 69

Which type of membrane protein might be dissociated from the membrane by changing the pH or the ionic strength?

Back 69

Peripheral membrnae protein

Front 70

What would you expect for the fatty acyl chains of the membrane phospholipids of bacteria grown at low temperature?

Back 70

Proportion of unsaturated fatty acyl groups increases

Front 71

Why should it not be surprising that for many cells water requires a protein for its transport across a membrane?

Back 71

Water is very polar which inhibits its free diffusion across the membrane.

Front 72

you have purified a cell membrane and wish to isolate a transport protein from it. Which treatment might you select?

Back 72

Add a detergent.

Front 73

Common Aldoses

Back 73

Glyceraldehyde

Ribose

Glucose

Galactose

Hint 73

Front 74

Common Ketoses

Back 74

Dihydroxyacetone

Ribulose

Fructose

Hint 74

Front 75

Mono-Saccharide Classification

Back 75

Carbon Back Bone:

Triose (three carbon backbone)

Pentose (Five carbon backbone)

Hexose (Six carbon backbone)

Location of Carbonyl Group:

Aldose (carbonyl at the end. Aldehyde group.)

Ketose (carbonyl group in the middle. Ketone group.)

Front 76

Polysaccharide Examples/ Functions

Back 76