1. Carbohydrates

Question 1

most carbohydrates are

Answer 1

polymers

Question 2

carbohydrates are made from

Answer 2

monosaccharides

Question 3

glucose is what kind of sugar

Answer 3

hexose sugar

Question 4

two types of glucose

Answer 4

alpha glucose and beta glucose

Question 5

difference between the 2 types of glucose

Answer 5

they are isomers (molecules of same molecular formula but with atoms connected in a different way)

Question 6

a condensation reaction is when

Answer 6

2 molecules join with formation of new chemical bond and a water molecule is released

Question 7

monosaccharides are joined together by

Answer 7

condensation reactions

Question 8

what mond forms between monosaccharides

Answer 8

glycosidic

Question 9

when 2 monosaccharides join a

Answer 9

disaccharide is formed

Question 10

glucose + fructose

Answer 10

sucrose (disaccharide)

Question 11

glucose + galactose

Answer 11

lactose (disaccharide)

Question 12

glucose + glucose

Answer 12

maltose (disaccharide)

Question 13

hydrolysis reactions

Answer 13

break polymers into their monomers. by addition of water

Question 14

name of test for reducing sugars and non reducing sugars

Answer 14

benedicts test

Question 15

reducing sugars are

Answer 15

all monosaccharides and some disaccharides (maltose and lactose)

Question 16

how to test for reducing sugar

Answer 16

1. add benedicts reagent (which is blue) to sample
2. heat in a water bath thats been brought to the boil
3. if the test is positive it will form a coloured precipiytate

Question 17

change in colour precipitate for a reducing sugar

Answer 17

blue -> orange/brick red

Question 18

what indicates the concentration of a reducing sugar

Answer 18

the colour change
blue -> green -> yellow -> orange -> brick red
(further along, higher concentration)
OR filter solution and weigh precipitate

Question 19

test for non-reducing sugars (if result of reducing sugars is negative there could still be non-reducing sugar present)

Answer 19

first break down into monosaccahrides

1. add dilute HCl to new sample
2. carefully heat in water bath thats been brought to the boil
3. neutralise it with sodium hydrogencarbonate
4. . carry out benedicts test as you would for a reducing sugar.
5. positive test = coloured precip. negative test = remains blue.

Question 20

polysaccharide is

Answer 20

when more than 2 monosaccharides are joined

Question 21

Starch

is the main energy storage in

Answer 21

plants

Question 22

Starch

is a mixture of 2 polysaccharides

Answer 22

amylose

amylopectin

Question 23

Starch

amylose is

Answer 23

a long unbranched chain of alpha glucose

angles of glycosidic bonds give it a coiled structure = makes it compact and therefore good for storage

Question 24

Starch

amylopectin is

Answer 24

a long branched chain of alpha glucose

side branches allow enzymes that break it down to get to the glycosidic bonds easily = glucose can be released quickly

Question 25

Starch | is insoluble in water so

Answer 25

it doesnt affect water potential = doesnt cause water to enter cells by osmosis which would make them swell. = good for storage

Question 26

how to test for starch

Answer 26

iodene test add iodene dissolved in oitassium iodide solutiom to sample starch present the sample changes from browny-orange colour to a dark blue-black colour

Question 27

glycogen | is the main energy storage material in

Answer 27

animals

Question 28

glycogen | pollysaccharide of which glucose

Answer 28

alphaglucose

Question 29

glycogen | how is it similar to amylopectin

Answer 29

long and branched (more branched than amylopectin)

Question 30

glycogen | how is it good for storage

Answer 30

very compact

Question 31

glycogen | the fact it has lots of branches means

Answer 31

stored glucose can be released quickly (important for energy release in animals)

Question 32

cellulose | is the major component of

Answer 32

cell walls in plants

Question 33

cellulose | is made of

Answer 33

long unbranched chains of beta glucose | when bet glucose molecules bond they form straight cellulose chains

Question 34

cellulose | cellulose chains are linked together by

Answer 34

Hydrogen bonds to form strong fibres called microfibrils | strong fibres means cellulose provides structural support for cells