Carbohydrates

Question 1

What is a MONOMER?

Answer 1

Smaller molecules that make macromolecules

Question 2

What is a DIMER?

Answer 2

Macromolecule of CHEMICALLY BONDED monomers

Question 3

What is a POLYMER?

Answer 3

Many macromolecules

Question 4

Four function of carbohydrates?

Answer 4

Energy production and storage (starch, glycogen and glucose)

Recognition and signalling: at cell membrane, attached to proteins and phospholipids creating glycoproteins and glycolipids, which play a role in cell to cell communication.

Building blocks of DNA / RNA with back bone of 5-carbon pentose sugar and a phosphate.

Structure (cellulose with long chains forms tough protective walls for plant cells

Question 5

Three forms of carbohydrates?

Answer 5

1. Monosacchardies (monomers)
2. Disaccharides (dimers)
3. Polysaccarides (polymers)

Question 6

What are carbohydrates made of?

Answer 6

Carbon, Hydrogen and Oxygen

Question 7

What are simple and complex carbohydrages?

Answer 7

SIMPLE: mono and disaccharides.
COMPLEX: Polysaccharides

Question 8

Name three monosachharides.

How many carbons do they have, and what groups are they bound to?

Answer 8

3-9 carbon sugars bound to hydroxl (-OH) groups.

1. Glucose
2. Galactose
3. Fructose.

Question 9

Name three disaccharides?

Answer 9

1. Sucrose
2. Lactose
3. Maltose

Question 10

What is cellular respiration?

Answer 10

A metabolic process within the cell where biochemical energy is harvested from organic substances (usually glucose) and stores as ATP for energy requiring cellular activities.

Question 11

Name four polysaccharides?

Answer 11

1. Starch
2. Fibre
3. Glycogen
4. Cellulose

Question 12

What’s an isomer?

Give monosaccharide example

Answer 12

Same chemical formula but different arrangement.

alpha and beta glucose are examples, difference is only placement of -OH (down for alpha and up for beta). Fructose is also an isomer of glucose, but is 5-sided and very different structure. All are C6H1206.

Question 13

Different function of alpha and beta glucose?

Answer 13

Alpha glucose is used to produce ATP during cellular respiration. Beta glucose used to sythesise cellulose (polysaccharide). Both are 6-carbon sugars (hexose).

Question 14

What’s a disaccharide? How are they formed?

Answer 14

Two monosaccharides that have bonded together with a glycosidic bond in a condensation reaction.

Question 15

Three examples of disaccharides?

Answer 15

Sucrose (glucose + fructose)
Lactose (glucose + galactose)
Maltose (glucose + glucose)

Question 16

What is a condensation reaction?

Answer 16

Chemical process of two molecules making a larger more complex bio molecule involving the loss of a water molecule. The basis of synthesis of all complex macromolecules: glycogen, starch, cellulose.

Question 17

Explain maltose as condensation reaction?

Answer 17

Maltose is formed by condensation of two glucose molecules. Both have spare -OH nearby; H20 is released, and -O- is formed. Can be created frequently to make a polysaccharide. As it’s the 1-carbon and 4-carbon, can be called a-1-4-glycosidic link.

Question 18

What is a hydrolysis reaction?

Answer 18

Breaking bond with addition of H20 molecule.

Question 19

How is the disaccharide maltose broken down?

Answer 19

Hydrolysis reaction.

Matlase (found in phospholibid bilayer of the epithelial cells lining villi of small intestines) adds -OH and -H on either side of the glycosidic bond, replacing the H20 and creating the two monosaccharides of glucose.

Question 20

Chemical formula of condensation and hydrolysis of Maltose?

Answer 20

C6H12O6 + C6H12O6 –> C12H22O11 + H20

C12H22O11 –H2O–> C6H12O6 + C6H12O6

Question 21

Name three polysaccharides and discuss their solubility.

Answer 21

1. Starch
2. Glycogen
3. Cellulose

Insoluble in water; good forms of storage as they don’t influence the osmotic balance of cells.

Question 22

How is starch used by the body?

Answer 22

Complex storage compound stored in roots of plants.

Amylase produced by salivary glands in mouth hydrolysis reaction to create Maltose.

Second hydrolysis reaction using maltase in small intestines to form glucose.

Glucose then transported through epithelial cells lining the villi via facilitated diffusion and active transport, absorbed into the blood stream (with O2) and transported to respiring cells.

Moderately branched.

Insoluble in water thus doesn’t effect osmotic balance of cells.

Question 23

How is glycogen used by the body?

Answer 23

Made from pure glucose, stores as energy reserve in muscles and liver cells. Formed by successive condensation reactions.

Highly branched.

Insoluble in water thus doesn’t effect osmotic balance. of cells.

Question 24

Four biological functions of carbohydrates

Answer 24

ENERGY PRODUCTION AND STORGE:
Polysaccharides glycogen and starch.
(main carbohydrate: glucose).

RECOGNITION/SIGNALLING: At cell membrane carbohydrates attached to :

• proteins forming GLYCOPROTEINS
• phospholipids called GLYCOLIPIDS

play a role in cell to cell communication.

BUILDING BLOCKS FOR DNA/RNA: Backbone of these nucleic acids are made of pentose 5-carbon sugar (dioxyribose and ribose) and a phosphate group.

STRUCTURE: Cellulose is made of long strands, which helps form the tough protective layer around plant cells.

Question 25

Branching of polysaccharides

Answer 25

Starch - moderately branched
Glycogen - highly branched
Cellulose - long strands un-branched