Week 3 lecture 5 and 6

Question 1

What are the four major elements of life?

Answer 1

Hydrogen, carbon, nitrogen and oxygen

Question 2

Define carbohydrate

Answer 2

Molecules possessing the empirical chemical formula [CH2O]n

Question 3

What are carbohydrates?

Answer 3

Aldehyde or ketone compounds with multiple hydroxy groups

Question 4

What class of compounds makes up most of the organic matter on Earth?

Answer 4

Carbohydrates

Question 5

What are the chemical names of the two types of carbohydrate?

Answer 5

Polyhydroxy aldehydes

Polyhydroxy ketones

Question 6

What chemical functional groups are present in carbohydrates?

Answer 6

Ketones or aldehydes

Alcohol

Question 7

What are the functions of carbohydrates?

Answer 7

Energy stores, fuels, metabolic intermediates, structural framework for DNA/RNA, structural elements, mediation of interactions

Question 8

Why are carbohydrates involved in mediating interactions between cells and between cells and their environment?

Answer 8

Huge structural diversity (monosaccharides vary in size, sterioisomers)

Question 9

What is the name of the three carbon (triose) aldehyde sugar?

Answer 9

L-glyceraldehyde

Question 10

Name the smallest ketone monosaccharide

Answer 10

dihydroxyacetone

Question 11

Glucose is not the most abundant carbohydrate ingested, why is it the most abundant absorbed into the blood stream?

Answer 11

Digestion

Question 12

What is the most ingested carbohydrate?

Answer 12

Starch (a polymer of glucose)

Question 13

Name three other carbohydrates present in the body that can be derived from glucose

Answer 13

Ribose/deoxyribose
lactose
glycogen

Question 14

Where is glucose the sole fuel molecule in the body?

Answer 14

Brain and red blood cells

Question 15

Name 4 diseases associated with abnormal carbohydrate metabolism

Answer 15

Diabetes (Mellitus)
Galactosaemia
Fructose intolerance
Lactose intolerance

Question 16

What are monosaccharides?

Answer 16

Basic units of carbohydrates that cannot be broken down into simpler sugars

Question 17

What are disaccharides?

Answer 17

Composed of two monosaccharide units, which may be the same or different

Question 18

What disaccharide is composed of two glucose sugar units?

Answer 18

Maltose

Question 19

What is sucrose composed of?

Answer 19

Glucose and fructose

Question 20

What is lactose composed of?

Answer 20

Glucose and galactose

Question 21

What are oligosaccharides?

Answer 21

Defined as containing between 3 and 10 monosaccharide units, the same or a mixture

Question 22

A polysaccharide may be ____ (e.g. cellulose) or _____ (e.g. glycogen, starch)

Answer 22

Linear

Branches

Question 23

What type of polysaccharide contain only one type of monosaccharide unit?

Answer 23

Homopolysaccharides

Question 24

Name three examples of homopolysaccharides

Answer 24

Cellulose, glycogen, starch

Question 25

What type of polysaccharide contain two or more different types of monosaccharide unit?

Answer 25

Heteropolysaccharides

Question 26

Name 4 examples of heteropolysaccharides

Answer 26

Heperin, mucins, glycoproteins, hyaluronic acid

Question 27

Why are monosaccharides important?

Answer 27

As fuel molecules and building blocks for nucleic acids

Question 28

What additional functional groups do more common complex monosaccharides have?

Answer 28

Carboxylic acid and amino groups

Question 29

How many carbon atoms do monosaccharide sugars contain?

Answer 29

minimum 3 | no maximum

Question 30

How many carbon atoms do important biological monosaccharides contain?

Answer 30

3 to 6 (trioses, tetroses, pentoses, hexoses)

Question 31

What is the most common number of carbon atoms in biologically important monosacchrides?

Answer 31

5 and 6

Question 32

Glyceraldehyde is also called

Answer 32

Aldose

Question 33

What is the difference between D and L enantiomers?

Answer 33

D (dexter) alcohol group is on the right | L alcohol group is on the left

Question 34

Where are all aldose sugars derived from?

Answer 34

Glyceraldehyde

Question 35

What series of aldose is found in the human metabolism?

Answer 35

D series

Question 36

What is the general rule for calculating the number of isomers for monosaccharides containing a defined number of carbon atoms?

Answer 36

Number of asymmetric carbons (N) | The number of carbons is 2^N

Question 37

What name is given to isomers that arrise due to asymemeteric carbons that are not mirror images?

Answer 37

Diasterioisomers

Question 38

What name is given to isomers that differ only at one position?

Answer 38

Epimers

Question 39

What groups can glucose contajn?

Answer 39

Amino group usually on C2 e.g. glucosamine

Question 40

What are deoxysugars?

Answer 40

Where a hydroxyl is replaced by -H

Question 41

Give examples of deoxysugars

Answer 41

Fucose (6-deoxygalactose) | Deoxyribose (C-5 sugar)

Question 42

What groups does glucose contain?

Answer 42

-OH, aldehyde group

Question 43

What can happen to the aldehyde group that glucose contains?

Answer 43

Can be oxidised or reduced

Question 44

How does glucose react with acids>

Answer 44

As alcohols | Gives esters

Question 45

How does glucose react with phosphoric acid?

Answer 45

As an alcohol | Gives phosphates

Question 46

How does glucose react with sulphuric acid?

Answer 46

As an alcohol | Gives sulfuric acid

Question 47

Glucose in the presence of bromine and water is oxidised to form?

Answer 47

Gluconic acid

Question 48

Glucose can be reduced in the presence of sodium and mercury to give?

Answer 48

Sorbitol

Question 49

Glucose in the presence of HNO3 is oxidised to give?

Answer 49

Glucaric acid