Bio Questions - Carbohydrates

Front 1

In people with diabetes,glucose is not removed from the blood and hence cannot bestored in reserve. This leads to a lack of the synthesis of___________________.

A.cellulose

B. glycogen

C. ATP

D. starch.

E. sucrose

Back 1

B.Glycogen

Front 2

Which of the following terms includes all others?

A. monosaccharide

B. disaccharide

C. starch

D. polysaccharide

E. carbohydrate

Back 2

E. Carbohydrate

Front 3

Which of the following molecules would NOT be found in plants?

A. starch

B. glucose

C. cellulose

D. glycogen

E. phospholipids

Back 3

D. Glycogen

Front 4

When a carbonyl is found at the end of a monosaccharide, _(4)_.

A. the sugar is called an aldose

B. the sugar is called a carbonose

C. the sugar is called a ketose

D. Trick question –monosaccharides do not have carbonyl groups!

Back 4

A. this sugar is an ALDOSE

Front 5

What is the major structural difference between glycogen and starch?

A. The types ofcarbons involved in bonds.

B. The degree of branching.

C. The length of the molecule

D. There is no difference

Back 5

B. The degree of branching

Front 6

What polysaccharide is an important component inthe structure of many insects and fungi?

A. Cellulose.

B. Starch.

C. Chitin.

D. Protein.

E. Glycogen.

Back 6

C. Chitin

Front 7

Enzymes that readily break apart starch cannothydrolyze the bonds found in cellulose. Why is this logical?

A. The geometry of the moleculesare different, and enzymes are shape-specific.

B. Starch is held together by hydrogen bonding,not covalent bonding.

C. Cellulose molecules are highly branched; enzymes are too bulky to fit.

D. Cellulose molecules are not put together bydehydration synthesis,

and thus could not be broken by hydrolysis?

Back 7

A. The geometry is different, and enzymes are shape-specific

Front 8

List some of the functions of carbohydrates

Back 8

Carbohydrates have six major functions within the body:

1. Providing energy and regulation of blood glucose

2. Sparing the use of proteins for energy

3. Breakdown of fatty acids and preventing ketosis

4. Biological recognition processes

5. Flavor and Sweeteners

6. Dietary fiber

Front 9

The alpha and beta forms of glucose, found in starch and cellulose, differ in ...

(a) Whether the molecule is a ring or an open chain.

(b) Whether the ring contains five or six C atoms.

(c) Whether the first C atom is bound to one or two O atoms.

(d) How one of the -OH groups is oriented.

(e) None of the above.

Back 9

(d) How one of the -OH groups is oriented.

One particular -OH group points to one side of the ring in alpha

glucose; the other side in beta glucose.

Front 10

Which feature is shared by all monosaccharides?

(a) In their linear forms, they all contain a carbonyl and several hydroxyl functional groups.

(b) They are all pentoses.

(c) In their linear forms, they all contain a carboxyl and several hydroxyl functional groups.

(d) They all contain more than one sugar.

Back 10

(a) In their linear forms, they all contain a

carbonyl and several hydroxyl functional groups.

Front 11

How do the α and β forms of glucose differ?

(a) Their ring structures differ in the location of a hydroxyl group.

(b) Their linear structures differ in the location of a hydroxyl group.

(c) The α form can be involved in 1,4- and 1,6-glycosidic linkages; the β form can participate only in 1,4 linkages.

(d) The oxygen atom inside the ring is located in a different position.

Back 11

(a) Their ring structures differ in the location of a hydroxyl group.

Front 12

Glycogen is _____.

(a) A source of saturated fat

(b) A polysaccharide found in animals

(c) A transport protein that carries oxygen

(d) A polysaccharide found in plant cell walls

(e) The form in which plants store sugars

Back 12

(b) A polysaccharide found in animals

Animals store energy in the form of glycogen.

Front 13

_____ is the most abundant organic compound on Earth.

(a) Cellulose

(b) Glucose

(c) Starch

(d) Glycogen

(e) Lactose

Back 13

(a) Cellulose

Cellulose, a component of plant cell walls, is the most abundant organic compound found on earth.

Front 14

Which statement is true of sucrose?

(a) It's a disaccharide.

(b) It contains glucose.

(c) It's table sugar.

(d) Both (a) and (c).

(e) - (a), (b), and (c).

Back 14

(e) - (a), (b), and (c)

We use sucrose as our table sugar because plants make plenty of it. They use it as their main circulating fuel, and sugar beets and sugar cane store a lot of it.

It's a disaccharide made of glucose and fructose .

Front 15

Glycogen ...

(a) Contains several kinds of sugars.

(b) Occurs in animal cells and has branches.

(c) Is stronger, weight for weight, than steel.

(d) Occurs in chloroplasts and stores energy.

(e) None of the above.

Back 15

(b) Occurs in animal cells and has branches.

Glycogen is the main energy-storing carbohydrate in animals and humans.

Front 16

Which of the following structural features is

common to cellulose, chitin, and peptidoglycan?

(a) They can all form bonds between polymer chains that create parallel strands.

(b) They are all composed of glucose in either the α or β form.

(c) They are all composed of highly branched fibers.

(d) They all contain peptide bonds.

Back 16

(a) They can all form bonds between polymer chains that create parallel strands.

Front 17

Cellulose is _____.

(a) A monomer of starch.

(b) A major structural component of plant cell walls

(c) A polymer composed of fructose monomers

(d) Used by plants to make glycogen

(e) A storage polysaccharide for energy in plant cells

Back 17

(b) A major structural component of plant cell walls .

Front 18

What is "high fructose corn syrup" ?

Back 18

High-fructose corn syrup is a common sweetener in sodas and fruit-flavored drinks

made from corn starch.

Front 19

Define and explain the realtionship between

Monosaccharides, triose, pentose and hexose?

Back 19

Monosaccharides:

most taste sweet; contain 3-7 carbon atoms, are either: ALDOSE (conatin an aldehyde group, or KETOSE (contain a ketose group); their names are composed by denoting the number of carbon atoms and the suffix -ose.

For example, the terms triose, pentose, and hexose signify monosaccharides with, respectively, three, five, and six carbon atoms.

Front 20

Define: Aldose, Ketose and isomers

Back 20

Monosaccharides are the simplest form of carbohydrates and may be subcategorized as aldoses or ketoses.

The sugar is an aldose if it contains an aldehyde functional group

A ketose signifies that the sugar contains a ketone functional group.

Isomeres are any of two or more substances that have the same molecular formula but differ in the way their atoms are connected to each other. Glucose, fructose and galactose are isomers, they have the same chemical formula (C6H12O6), but different structures.

Front 21

What are Oligosaccharides and Polysaccharides?

Back 21

Oligosaccharides are carbohydrates formed by the joining of 2 to 6 monosaccharide molecules,ie. Maltose - disaccharide formed in cells as a breakdown product of starch; Lactose - is a disaccharide found in milk and hence commonly called milk sugar; Sucrose is disaccharide found

extensively in plants. It is commonly called cane sugar.Polysaccharides: made up of many simple sugars chemically joined together (poly= many), ie.Starch (energy store in plants), glycogen (energy store in animals),

Cellulose (plant fibre)

Front 22

What are Monosaccharides?

Back 22

"Simple sugars" with the formula (C • H2O)n.

A monosaccharide is made up of one sugar (mono=one).

Have endings with "ose" : Fructose ("Fruit

Sugar"), Glucose, Galactose

Front 23

What are Carbohydrates?

Back 23

Carbohydrates are also known as sugars.

They are compounds of carbon, hydrogen and oxygen: C,H,O

1C : 2O : 1O (ie. C6H12O6)

Functions: * serve as raw material for synthesizing other molecules

* provide fibrous structural materials

* indicate cell identity

* store chemical energy

Front 24

What are disaccharides?

Back 24

A disaccharide is made up of two simple sugars chemically joined

together (di=2).

Examples:

Sucrose (Glucose + fructose = sugar cane/sugar beets)

Lactose (galactose + glucose = milk)

Maltose (glucose + glucose = in germinating grain)

Front 25

What are Glycoproteins ?

Back 25

Glycoproteins are proteins that have sugars attached to them.

They have diverse functions such as in our immune system, protection of our body, communication between cells, and our reproductive systems.

Front 26

What are monomers?

Back 26

Monomers=monosaccharides

They are monosaccharides that polymerize via

condensation reactions to form polymers like

polysaccharides.

The monosaccharides in polysaccharides are

joined by glycosidic linkages.

Front 27

What are the functional groups of monomers,

or monosaccharides?

Back 27

Carbonyl C=O

+ Hydroxyl OH-

Front 28

What are polymers?

Back 28

Oligosaccahrides: small polymers

(oligo=few) (3-50 monosaccharides)

Polysaccharieds: many polymers

(poly=many) (over 50 monos)

Front 29

Monosaccharides vary in structure by:

Back 29

1. Location of the carbonyl group= they have one carbonyl

- at either end of the sugar, or in the middle of the sugar

thus called Aldose, or Ketose

2. Number of Carbon atoms (Triose=3; Pentose=5; Hexose=6)

3. Spatial arrangement of the atoms

(configuration/location of the hydroxyl (C-OH) groups)

4. Linear and alternative ring forms

(Sugars tend to form rings in aqueous solutions)

Front 30

Difference between Aldose and Ketose?

Back 30

left: carbonyl (C=O) group at the

end of the carbon (C) chain=ALDOSE

right: carbonyl group in the middle

of the carbon chain= KETOSE

Front 31

Draw chemical formula of an aldose

and a ketose

Back 31

Glucose: 6 carbon aldehyde sugar

Fructose: 6 carbon ketose sugar

Front 32

Sugars exist in linear and ring forms

Back 32

Sugars normally have

3-7carbons and form ring shapes,

if they have 5 carbons or more

example here: GLUCOSE (in linear

and ring form)

Front 33

draw the glycosidic linkage of the disaccharide

Maltose

Back 33

Maltose: The hydroxyl group on C-1 is bonded with the hydroxyl group of C-4 of another molecule in form of a glycosidic link with the

elimination of water (h2O)

Front 34

re the 2 most comm

Back 34

2 most common glycosidic linkages:

α(1→4) glycosidic bonds and

β(1→4) glycosidic bonds

Linkage of sugars by hydrolysis takes place on the C1 carbon OH group

of the first ring in the α position and the C4 carbon OH group on the second ring. This connection is called a α(1→4) glycosidic bond,i.e.maltose,

glycogen. Linkage of the β glucose molecules on C1 and C4 OH group

is called β(1→4) glycosidic bonds, ie. cellulose.

Front 35

what is α and β Glucose?

Back 35

in β Glucose the OH group on

C1 is pointing up

in α Glucose the OH group on

C1 is pointing down

Front 36

Back 36

2 most common glycosidic linkages:α(1→4) glycosidic bonds and β(1→4) glycosidic bonds

Front 37

What are macromolecules?

Back 37

Have fifty-ish to thousands ofmonosaccharide monomers linked bydehydration synthesis = macromolecules!

1. Starch

2. Glycogen

3. Cellulose

4. Chitin

5. Peptidoglycan

Front 38

what are examples of polysaccharides?

Back 38

1. Glycogen in animals (highly branched α-glucose polymer)

2. Starch in plants (mixture of branched andunbranched

α-glucose polymer)

3. Cellulose in plants (polymer of β-glucose monomers)

4. Chitin in fungi/algae (comprised of N-acetylglucosamine (NAc)

monomers)

5. Peptidoglycan in bacterial cell walls (backbones of alternating

monosaccharides)

Front 39

What is starch?

Back 39

Storage (fuel) polysaccharide

in plants

the glucose molecules form helices in form of amylose (unbranched),

or amylopectin (branched)

Front 40

What is glycogen?

Back 40

* Storage (fuel) polysaccharide

in animals

* All of glucose

* Molecules form helices

* HIGHLY branched (more so than

amylopectin)

Front 41

what is cellulose?

Back 41

Structural polysaccharide

(cell wall support) in plants

All of β-glucose with β(1→4) linkage

Molecules form rods, sheets

Unbranched

Most abundant molecule on Earth!

Front 42

what is chitin?

Back 42

Structural polysaccharide – Cell walls of fungi

•Chitin is a modified polysaccharide that contains nitrogen (all of one N-containing glucose derivative)

•Exoskeletons of arthropods

•Molecules form rods, sheets

•Unbranched

Front 43

what is peptidoglycan ?

Back 43

Structural (cell wall) polysaccharide in bacteria

•All of N-containing glucose derivatives covalently cross-linked

with short proteins (peptido=Protein; Glycan=glucose derivative)

• Molecules form rods, sheets

• “Un”branched (polysaccharide component)

Front 44

How Do Carbohydrates Provide Structure?

Back 44

* Cellulose, chitin, and peptidoglycan form long strands then

organized into fibres, orlayered in sheets, to give cells and

organisms greatstrength and elasticity!

* the β-1,4-glycosidic linkages ofstructural carbohydrates are

very difficult to hydrolyze

Front 45

What do Carbohydrates Do?

Back 45

A. Furnish building blocks: used directly (in RNA), or can provide

raw “carbon skeletons” (in amino acids)

B. Provide: their shape makes them difficult to break

(Chitin; Cellulose)

C. Cell Identity: as Glycoproteins (proteins joined to carbohydrates

bycovalent bonds) - cell-cell recognition andcell-cell signalling

ie. red blood cells - different blood types

D. Store/provide chemical energy in cells (photosynthesis in plants/ATP)

Front 46

Explain Photosynthesis equation

Back 46

Front 47

Energy Stored in Glucose Is Transferred

to ATP

Back 47

When a cell needs energy, carbohydrates

participate inexergonic reactions that

synthesize adenosine triphosphate(ATP):

CH2O + O2 + ADP + Pi → CO2 + H2O + ATP

Carbohydrates contain a large number of

C–H bonds, whichhave high free energy.

Front 48

How Do Carbohydrates Store Energy?

Back 48

Starch and glycogen are efficient energy-storagemolecules, because

the α-linkages are readilyhydrolyzed,

The enzymes amylase and phosphorylase catalyzethe hydrolysis

of α-glycosidic linkages inglycogen and starch, respectively.

The releasedglucose subunits can then be used in theproduction

of ATP.

Front 49

Taste receptors and sweeteners

Back 49

* We have taste receptors (TAS1R3) for sweetness, this tells us

a food is high in energy.

* A common sweetener, glucose–fructose (also called highfructose

corn syrup) is found in processed foods

* made by converting starch to glucose, then some glucose is

converted tofructose because glucose-fructose is both sweeter

and cheaper than sucrose

Front 50

Artificial sweeteners

Back 50

* Sucrose, sucralose, saccharin...

* Artificial sweeteners taste sweet becausethey bind to the

TAS1R3 (taste) receptor in tongue.

* The hydroxyl groups (OH) on sucrosereplaced with chlorine (Cl)

Front 51

Types of Sweeteners Made from

Plant Sugars?

Back 51

1. Table sugar (sucrose): from sugar beets/cane

2. Honey (glucose/fructose mixture):

flower nectar + bees

3. Glucose-Fructose: Corn + corn starch