Carbohydrates

Question 1

Carbohydrates have tremendous structural________

Answer 1

diversity

Question 2

Name some ways that Carbohydrates differ

Answer 2

-chemical composition
-stereochemistry
-cyclisation
-size
-energy storage and structure

Question 3

What are Carbohydrates made from?

Answer 3

monosaccharides

Question 4

Monosaccharides (like amino acids) contain more than one_________ (chiral) centre and they occur as________ ______ ______

Answer 4

-asymmetric
-optically active isomers

Question 5

What are most naturally occurring monosaccharides?

Answer 5

D-isomers

Question 6

How can D-isomers be defined?

Answer 6

the chirality of the asymmetric carbon most distant from the carbonyl carbon

Question 7

What is a 5-membered ring called?

Answer 7

funarose

Question 8

What is a 6-membered ring called?

Answer 8

pyranose

Question 9

How does cyclisation of D-glucose occur? What does it lead to the formation of?

Answer 9

by nucleophilic attack of the C5 hydroxyl on the C1 aldehyde forming the hemiacetal

Question 10

How does the configuration of alpha and beta glucopyranose differ?

Answer 10

about the hemiacetal carbon and they are called anomers

Question 11

How are Carbohydrates classified?

Answer 11

by size

Question 12

What is an example of a Monosaccharide?

Answer 12

D-glucose (dextrose)–> the most abundant saccharide

Question 13

What is an example of an Oligosaccharide?

Answer 13

Sucrose (composed of D-glucose and D-fructose)

Question 14

What is an example of a Polysaccharide?

Answer 14

Cellulose ( a linear chain)
Glycogen (a branched chain).

Question 15

How does the Polymerisation of Monosaccharides occur?

Answer 15

condensation (dehydration) reaction between 2 or more monosaccharides with the elimination of water molecules

Question 16

How are Polysaccharides distinguished?

Answer 16

-identity of recurring units
-chain lengths
-types of bonds linking units

Question 17

What is an oligosaccharide

Answer 17

A carbohydrate composed of 2 to 10 monosaccharide units.

Question 18

What functional groups are found in linear monosaccharides?

Answer 18

Hydroxyl groups (-OH) and either an aldehyde or ketone group.

Question 19

What is the difference between an aldose and a ketose?

Answer 19

An aldose contains an aldehyde group, while a ketose contains a ketone group.

Question 20

What is the significance of D-glucose?

Answer 20

It is a primary energy source for cells and a key carbohydrate in metabolism.

Question 21

Describe the cyclisation of monosaccharides

Answer 21

The process where linear forms of monosaccharides form cyclic structures, typically in aqueous solutions.

Question 22

What are the two forms of D-glucose?

Answer 22

Linear form and cyclic form (α and β anomers).

Question 23

What are the distinguishing features of polysaccharides?

Answer 23

They are long chains of monosaccharides that can be branched or unbranched and have various functions.

Question 24

Name three important polysaccharides

Answer 24

Starch, glycogen, and cellulose.

Question 25

What is the primary function of starch?

Answer 25

It serves as an energy storage molecule in plants.

Question 26

What role does glycogen play in animals?

Answer 26

It is the main storage form of glucose in animal cells.

Question 27

Describe the structure of cellulose

Answer 27

It is a linear polysaccharide composed of β-glucose units, providing structural support in plant cell walls

Question 28

What is photosynthesis?

Answer 28

The process by which plants convert solar energy into chemical energy, producing sugars

Question 29

What is aerobic respiration?

Answer 29

The process of breaking down glucose in the presence of oxygen to produce ATP.

Question 30

Define hemiacetal

Answer 30

A compound formed from the reaction of an alcohol with an aldehyde or ketone.

Question 31

What are polyhydroxy aldehydes?

Answer 31

Monosaccharides with multiple hydroxyl groups and an aldehyde group.

Question 32

What are polyhydroxy ketones?

Answer 32

Monosaccharides with multiple hydroxyl groups and a ketone group.

Question 33

What is the significance of hydroxyl groups in carbohydrates?

Answer 33

They contribute to the solubility and reactivity of sugars.

Question 34

What is the importance of the stereochemical properties of monosaccharides?

Answer 34

They determine the biological activity and function of sugars.

Question 35

How does the structure of D-glucose differ in its cyclic forms?

Answer 35

The orientation of the hydroxyl group on the first carbon differentiates α-D-glucose from β-D-glucose.

Question 36

What is the role of carbohydrates in cellular functions?

Answer 36

They provide energy, serve as structural components, and play roles in cell signalling

Question 37

What is the process of polymerisation in carbohydrates?

Answer 37

The chemical reaction where monosaccharides link together to form larger carbohydrate molecules.

Question 38

How are starch and glycogen structurally different?

Answer 38

Starch is primarily unbranched (amylose) or branched (amylopectin), while glycogen is highly branched.

Question 39

What is the biological location of cellulose?

Answer 39

It is found in the cell walls of plants, providing rigidity and strength.