Carbohydrates

Question 1

What are the3 types of carbohydrates?

Answer 1

Monosaccharides = monomers, polysaccharides and disaccharides

Question 2

Name some monosaccharides

Answer 2

Glucose and fructose and galactose

Question 3

Name some polysaccharides

Answer 3

Starch glycogen chitin cellulose

Question 4

Name some disaccharides / dimer

Answer 4

Sucrose lactose maltose

Question 5

What elements are in carbohydrates

Answer 5

Carbon, hydrogen oxygen

Question 6

Functions of carbohydrates

Answer 6

Instant energy source, because respiration by glucose and transportables or storage forms of energy and structural materials glycoproteins in cell membranes

Question 7

3,5,6 carbon molecules = sugar name?

Answer 7

Triose,pentose, hexose

Question 8

General formula carbohydrates

Answer 8

(CH2O)n

Question 9

Why is it good that glucose is a polar molecule

Answer 9

Very soluble and transported in blood stream

Question 10

What are the 2 types of glucose and how are they different

Answer 10

Alpha and beta glucose. They are isomers (same formula but different arrangement in space). In alpha, OH group is below carbon 1 but above carbon 1 in beta

Question 11

How is water a polar molecule

Answer 11

Oxygen atom has slightly negative charge because it attracts electrons and hydrogen is slightly positive because the electrons move away

Question 12

Define polar molecule

Answer 12

Slightly uneven distribution of charge across different parts of a molecule leading to no overall charge

Question 13

Which monosaccharides make up lactose sucrose and maltose

Answer 13

Lactose = galactose + glucose
Sucrose= glucose + fructose
Maltose= glucose + glucose

Question 14

What happens in a condensation reaction for carbs

Answer 14

Larger molecules form, new covalent glycosidic bond forms and water molecule is removed from smaller molecules being combined

Question 15

What happens in hydrolysis reaction for carbs

Answer 15

Smaller molecules formed, covalent bond broken, water molecule added from large molecules being broken down

Question 16

What are polysaccharides and why are they ideal storage molecules (starch + glycogen)

Answer 16

Polymers made from glucose molecules and ideal because they are compact as they are coiled and branched and insoluble so don’t affect the osmotic potential and its easy to add and remove glucose molecules because branched ends means lots of glucose molecules released at once l have high energy content

Question 17

Starch → purpose: energy source for humans

Answer 17

Polymers amylopectin and amylose
Amylose is a straight coiled chain of alpha glucose molecules joined by 1-4 glycosidic bonds and amylopectin is a branched and coiled chain with 1-4 bonds and the branches form between carbons 1 and 6 of adjacent monomers

Question 18

Glycogen

Answer 18

The energy store for animals in liver + muscle cells - polymer of alpha glucose - with 1,4 glycosidic bonds creating coiled chain (more coiled then and amylopectin) due to sidechains attached by 1,6 glycosidic bonds so more compact than starch and stored as granules in liver and muscle cells

Question 19

Cellulose

Answer 19

Structural role in plant cell walls - long straight chains of beta glucose with 1,4 glycosidic bonds + every other glucose molecule rotated 180° relative to next molecules H bonds form between long multiple chains like layers = microfibril = very strong

Question 20

Chitin

Answer 20

Cell walls for fungi and exoskeletons of insects ( contains nitrogen) with beta glucose + same structure as cellulose but OH group on carbon 2 replaced with acetyl amide side chain containing nitrogen

Question 21

Definition of disaccharide / how are they formed

Answer 21

Two monosaccharides joined together by a condensation reaction with glycosidic bond joining two hexose units

Question 22

Monomer for chitin

Answer 22

B glucose with acetyl amide side chain

Question 23

Structural formula for monosaccharides

Answer 23

Either straight chain or rings

Question 24

What type of bond is important in helping maintain shape of biological molecules

Answer 24

Hydrogen bonding

Question 25

Structure and resulting function of starch and glucagon

Answer 25

Long chains of glucose → long chains mean that glucose molecules can readily break off at ends when required for respiration
Insoluble → doesn’t affect osmotic potential or movement entering / leaving cell → glycogen more compact than starch due to side chains and compact so suitable for storage of energy

Question 26

General structure and resulting function of cellulose

Answer 26

Hydrogen bonds between OH groups of parallel chains making microfibril = structural support for plant cell walls and very strong preventing cell from bursting when plants become turgid

Question 27

Why is chitin important to insect body structure

Answer 27

Microfibril with many chains and hydrogen bonds = strong, hard, flexible, lightweight + waterproof

Question 28

Two key properties of monosaccharides and disaccharides

Answer 28

Sweet and soluble