Carbohydrates

Question 1

What are the elements found in carbohydrates

Answer 1

Carbon, hydrogen, oxygen

Question 2

What are the 3 reason that carbohydrates are important

Answer 2

They are a source of short term energy for a cell
They are the main reactant in cellular respiration
They are necessary to build biological molecules.

Question 3

What are the functional groups in carbohydrates

Answer 3

carbonyl and hyrdoxyl

Question 4

Functions of carbohydrates

Answer 4

Source of energy
Building materials
Cell surface markers for cell to cell identification and communication

Question 5

Monosaccharides

Answer 5

Made up of 1 simple sugar. Most common is glucose others include galactose and fructose. Glucose is produced during photosynthesis, galactose is in milk and fructose is in fruits.

Question 6

What process produces majority of carbohydrates

Answer 6

Photosynthesis

Question 7

Draw glucose, fructose and galactose

Question 8

Difference between glucose and galactose

Answer 8

Different shapes
Different physical and chemical properties

Question 9

Isomers

Answer 9

Same chemical formula but different arrangement of atoms.

Question 10

2 forms of glucose

Answer 10

alpha glucose where the 1 oh group on carbon points downwards and beta glucose where 1 oh group point upwards

Question 11

ribose

Answer 11

a 5 carbon sugar(pentose) found in DNA and RNA
Fructose is a type ribose

Question 12

2 types of ribose

Answer 12

Ribose- OH group on C2
Deoxyribose- missing oxygen on C2

Question 13

Disaccharide

Answer 13

Made of 2 monosaccharides and are joined by a glycosidic link and all have 1 glucose

Question 14

Example of disaccharides

Answer 14

Maltose- glucose +glucose (grains)
Sucrose- glucose+fructose (table sugar
Lactose- glucose+galactose (milk)

Question 15

Condensation/ dehydration synthesis reaction

Answer 15

When two monosaccharides combine, there is a loss of an OH from one molecule and an H from another molecule, which together form H2O as a byproduct.
The resulting bond is called a glycosidic linkage. Anabolic (forming complex molecules)

Question 16

Polysaccharides

Answer 16

Complex carbohydrates
Hundreds of glucose molecules formed by glycosidic bonds

Question 17

Functions of Polysaccharides

Answer 17

Energy storage(animals) and structural support(plants). (insoluble in water)

Question 18

Energy storage of polysaccharides

Answer 18

Starch-
Glycogen-polymer of alpha glucose in animals (stored in liver if excess)

Question 19

Structural polysaccharides

Answer 19

Chitin- Modified glucose units containing functional groups in insect exoskeleton. found in fungal cells
Cellulose-polymer of beta glucose in plant cell walls

Question 20

Starch

Answer 20

• polymer of alpha glucose in plants (skeleton for plants)
• mixture of 2 polysaccharides
• amalyose which is unbranched(consists entirely of monomers connected by 1-4 glycosidic linkages )
• amylopectin branched ( consists of mostly 1-4 linkages, but some periodic 1-6 which gives it a branching effect )
• Insoluble
  -Excess glucose is stored in the form of starch in plants

Question 21

Glycogen

Answer 21

-stored in liver and muscle cells.
-Whenever blood glucose levels decrease, glycogen is broken down (via hydrolysis) to release glucose monomers that cells can absorb and use.
Α-1,4-link glycosidic

Question 22

Cellulose

Answer 22

• Polymer of β-glucose
• β 1,4 link (alternating bond orientation)
• H-bonds between cellulose molecules form bundles with high tensile strength

Question 23

Why can’t we digest cellulose

Answer 23

-The chains of polysaccharides cluster together to form parallel bundles that are held together by hydrogen bonds between hydroxyl groups
- makes them extra strong so they can’t be broken by human digestive enzymes.

Question 24

Chitin

Answer 24

• made out of modified glucose units that bear a nitrogen-containing functional group
• the hard exoskeleton of arthropods is made of chitin
• found in the cell walls of fungi
  Similar to cellulose

Question 25

Hydrolysis

Answer 25

• opposite of a condensation reaction
• in the presence of water and an enzyme the “glycosidic linkage” is broken.