Carbohydrates

Question 1

What are organic molecules?

Answer 1

Molecules containing carbon, carbon-carbon or carbon-hydrogen bonds.

Question 2

Monomers definition

Answer 2

Monomers are small repeating units from which larger molecules called polymers are made

Question 3

Polymer definitions

Answer 3

Polymers are molecules from large numbers, 3 or more, joined together

Question 4

Carbohydrate monomers

Answer 4

Monosaccharides e.g. glucose, fructose and galactose

Question 5

Carbohydrate dimers

Answer 5

Disaccharides e.g. maltose, lactose and sucrose

Question 6

Carbohydrate polymers

Answer 6

Polysaccharides e.g. starch, cellulose and glycogen

Question 7

Protein monomers

Answer 7

Amino acids e.g. glycine and tyrosine

Question 8

Protein polymers

Answer 8

Polypeptides + proteins e.g. haemoglobin and enzymes

Question 9

Nucleic acid monomers

Answer 9

Nucleotides e.g. thymine and adenine

Question 10

Nucleic acid polymers

Answer 10

Polynucleotides e.g. DNA and RNA

Question 11

In carbohydrates what are the bonds called?

Answer 11

Glycosidic bonds

Question 12

In proteins what are the bonds called?

Answer 12

Peptide bonds

Question 13

In DNA what are the bonds called?

Answer 13

Phosphodiester bonds

Question 14

What are condensation reactions?

Answer 14

Joining of two molecules with a chemical bond, involving the elimination of a water molecule.

Question 15

What is the purpose of a condensation reaction?

Answer 15

Required to join monomers, to form dimers and polymers. For every new bond formed, a water molecule is formed.

Question 16

What are hydrolysis reactions?

Answer 16

To break chemical bonds between two monomers involves using a water molecule

Question 17

What is the purpose of hydrolysis reactions?

Answer 17

To break apart polymers and dimers, because only monomers are small enough to cross the cell membrane

Question 18

What is an isomer?

Answer 18

Molecules that have the same molecular formula but different atom arrangements

Question 19

Isomers of glucose

Answer 19

Alpha and Beta

Question 20

Alpha glucose bonding type

Answer 20

1-4 and 1-6 glycosidic bonding

Question 21

Beta glucose bonding type

Answer 21

1-4 glycosidic bonding

Question 22

Glucose + glucose = ?

Answer 22

Maltose -> Germinating seeds

Question 23

Glucose + galactose = ?

Answer 23

Lactose -> milk sugar

Question 24

Glucose + fructose = ?

Answer 24

Sucrose -> cane sugar, transported in the phloem of plants

Question 25

Monosaccharide molecular formula

Answer 25

C6 H12 O6

Question 26

Disaccharide molecular formula

Answer 26

C12 H22 O11

Question 27

Trisaccharide molecular formula

Answer 27

C18 H32 O16

Question 28

Structure and functions of starch: (Plants)

Answer 28

-Alpha glucose -> 1-6 bonding, making it highly branched to provide more ends for enzyme action and faster and easier hydrolysis
-Alpha glucose -> Break down into glucose for respiration
-Insoluble -> Allow plants to maintain a water potential, so doesn’t affect the amount of water osmosis
-Helical structure -> Makes it compact, so many molecules can fit into a small space
-Large molecule -> Cannot pass across the cell membrane

Question 29

Purpose of starch

Answer 29

Ready and consistent source of energy over a longer period of time

Question 30

Structure and function of glycogen: (animals)

Answer 30

-Helical structure -> Makes it compact so many molecules can fit into small spaces
-Insoluble -> Doesn’t affect water osmosis as water potential doesn’t change
-Large molecules ->Doesn’t pass across the cell membrane
-Alpha glucose -> 1-6 bonding, so it’s highly branched providing more ends for faster hydrolysis used for respiratory substances

Question 31

Purpose of glycogen

Answer 31

Stored in the liver and muscle. Animals have higher metabolic demands, so adapted to have; shorter chains, highly branched 1-6 bonds and large surface area

Question 32

Structure and functions of cellulose: (plants)

Answer 32

Long straight chains of beta glucose, each molecule flips 180 degrees to create several chains of cellulose joined together by weak hydrogen bonds ( formed between the OH group), this forms microfibrils wound to form cellulose fibres. This provides strength and support to the cell wall, which can resist somatic pressure and prevent osmotic lysis.

Question 33

Similarities between cellulose and starch:

Answer 33

-Both are polysaccharides.
-Both have glycosidic bonds.
-Both contain carbon, hydrogen and oxygen.

Question 34

Differences between cellulose and starch:

Answer 34

-Starch is alpha glucose but cellulose is beta glucose.
-Starch is helical whereas cellulose is straight chains.
-Starch is branched whereas cellulose isn’t/ it’s straight
-Cellulose forms microfibrils whereas starch doesn’t.
-Starch does 1-4 and 1-6 glycosidic bonding whereas cellulose has 1-4 only as well as hydrogen bonds

Question 35

Starch is made from what?

Answer 35

2 polysaccharides, it has one unbranched component

Question 36

Glycogen and cellulose is made from what?

Answer 36

1 polysaccharide, (glycogen has the most bonds)

Question 37

What is starch found?

Answer 37

In the stomata of chloroplasts of plants

Question 38

Where is glycogen found?

Answer 38

In liver and muscle cells of animals

Question 39

Where is cellulose found?

Answer 39

In the cell walls of plants

Question 40

Where is cellulose found?

Answer 40

In the cell walls of plants

Question 41

What are the common monosaccharides; glucose, galactose and fructose used for?

Answer 41

Commonly found in fruits giving them a sweet flavour. They are soluble

Question 42

Alpha glucose monomers

Answer 42

Maltose, sucrose, lactose, starch and glycogen