module 2 - 3.3 carbohydrates - glucose, starch and glycogen

Question 1

what 3 elements are carbs made up of?

Answer 1

carbon, hydrogen, oxygen

Question 2

what is a monosaccharide?

Answer 2

small, simple sugar

Question 3

what is a disaccharide?

Answer 3

large sugars

Question 4

what is a polysaccharide?

Answer 4

long chain carbohydrates

Question 5

what are examples of a monosaccharide?

Answer 5

glucose, fructose and ribose

Question 6

what are examples of a disaccharide?

Answer 6

lactose and sucrose

Question 7

what are examples of a polysaccharide?

Answer 7

glycogen, cellulose and starch

Question 8

what are carbohydrates?

Answer 8

substances used as energy sources and structural materials in organisms

Question 9

how many carbons does a glucose molecule have?

Answer 9

6

Question 10

what type of sugar is glucose?

Answer 10

hexose sugar

Question 11

why is glucose important?

Answer 11

• main energy source for most cells
• main way carbohydrates are transported around the body
• highly soluble

Question 12

what are the different forms of glucose called?

Answer 12

structural isomers

Question 13

what are 2 common isomers?

Answer 13

alpha glucose
beta glucose

Question 14

what is the difference between alpha and beta glucose?

Answer 14

alpha - OH- attached below carbon 1
beta - OH- attached above carbon 1

Question 15

how are carbons 1,2,3 and 4 positioned?

Answer 15

clockwise (right to left)

Question 16

which reaction makes disaccharides and polysaccharides?

Answer 16

condensation reaction

Question 17

how are disaccharides formed?

Answer 17

when 2 monosaccharide molecules join together with a glycosidic bond

Question 18

what are pentoses?

Answer 18

sugars of DNA

Question 19

what does DNA stand for?

Answer 19

deoxyribonucleic acid

Question 20

what do pentose disaccharides contain?

Answer 20

5 carbon atoms (enough to form a ring)

Question 21

what are 2 important pentose molecules?

Answer 21

ribose and deoxyribose (structural isomers)

Question 22

what are ribose and deoxyribose important components of?

Answer 22

RNA and DNA

Question 23

what is the difference between ribose and deoxyribose?

Answer 23

• ribose has 1 H atom and 1 -OH group attached to carbon 2
• deoxyribose has 2 H atoms and no -OH group

Question 24

what are polysaccharides made of?

Answer 24

polymers containing many monosaccharides linked by glycosidic bonds

Question 25

what is the structure of starch?

Answer 25

a polysaccharide made of many alpha glucose molecules arranged into 2 different structural units

Question 26

what are the 2 different structural units of starch?

Answer 26

amylose and amylopectin

Question 27

what is maltose (malt sugar) formed of?

Answer 27

2 glucose molecules joined by an alpha 1-4 glycosidic bond

Question 28

what is sucrose (table sugar) formed of?

Answer 28

glucose and fructose molecules joined by an alpha 1-4 glycosidic bond

Question 29

what is lactose (milk sugar) formed of?

Answer 29

glucose and galactose molecules joined by an alpha 1-4 glycosidic bond

Question 30

why is starch important?

Answer 30

it is the major carbohydrate storage in plants

Question 31

what is starch usually stored as?

Answer 31

plastids - intracellular starch grains in organelles

Question 32

what do plastids contain?

Answer 32

green chloroplasts colourless amyloplasts

Question 33

what is starch produced from?

Answer 33

glucose made during photosynthesis

Question 34

what is glycogen?

Answer 34

animals store carbohydrates as glycogen

Question 35

what is the structure of glycogen?

Answer 35

contains many alpha 1-6 glycosidic bonds - produces a branched structure

Question 36

how is glycogen stored?

Answer 36

stored as small granules, particularly in muscles and liver

Question 37

what is glycogen like compared to starch?

Answer 37

glycogen - more dense, more soluble, breaks down more rapidly

Question 38

what is a hydrolysis reaction?

Answer 38

used to break down polysaccharides and disaccharides into monosaccharides

Question 39

what is cellulose?

Answer 39

polysaccharide and is the main part of plant cell walls

Question 40

how is cellulose different from starch?

Answer 40

cellulose is very strong, and prevents cells from busting when they take excess water

Question 41

what is the structure of cellulose?

Answer 41

consists of long chains of beta glucose molecules joined by beta glucose 1-4 glycosydic bonds

Question 42

when is starch broken down?

Answer 42

during respiration for energy

Question 43

what is starch also a source of?

Answer 43

carbon - for producing other molecules