1.1 - chemical elements and biological compounds

Question 1

what are the 4 living things biological molecules are made up of?

Answer 1

carbohydrates, lipids, proteins and nucleic acids

Question 2

what can carbohydrates, lipids, proteins and nucleic acids been named as? what are their general formulas?

Answer 2

macromolecules

CH2O

Question 3

what is meant by a monosaccharide?

Answer 3

a single unit - building blocks of life, sugar molecules, determined by C atoms

Question 4

what would we called a monosaccharide with 3 C atoms? 5 C atoms? 6 C atoms?

Answer 4

triose sugar
pentose sugar
hexose sugar

Question 5

what is the most common hexose sugar?

Answer 5

alpha glucose

Question 6

how would you draw a-glucose?

Answer 6

!

Question 7

what formula do hexose sugars like a-glucose have?

Answer 7

C6 H12 O6

Question 8

what is the difference between a-glucose and beta glucose?

Answer 8

a - glucose = H at top OH on bottom

beta glucose = OH at top H on bottom

Question 9

what two isomers does glucose have?

Answer 9

alpha and beta glucose

Question 10

what monosaccharides make up the disaccharide sucrose?

Answer 10

frutose and glucose

Question 11

what monosaccharides make up the disaccharide maltose?

Answer 11

a-glucose and a-glucose

Question 12

what monosaccharides make up the disaccharide lactose?

Answer 12

galactose and a-glucose

Question 13

what is a polysaccharide?

Answer 13

3 or more sugars joined together e.g. starch

Question 14

how is a monosaccharide turned to a disaccharide? what reaction? what bond is formed?

Answer 14

condensation reaction forms a glycosidic bond -water is made and H and OH comes off

Question 15

how is a disaccharide turned to a monosaccharide? what reaction?

Answer 15

hydrolysis - water splits up

Question 16

glucose is stored as…in…?

Answer 16

starch in plants

Question 17

is starch insoluble what does this mean?

Answer 17

yes. cannot be dissolved - prevents diffusion

Question 18

what is starch made up of?

Answer 18

amylose and amylopectin

Question 19

describe amylose?

Answer 19

formed by condensation reaction between 3+ a-glucose, 1,4 links - coiled springs are formed

Question 20

describe amylosepectin?

Answer 20

formed by condensation reaction but with beta glucose but 1,6 links and a branched structure

Question 21

what is the test for starch?

Answer 21

iodine solution, positive = blue/black

negative=brown/yellow

Question 22

what does polysaccharide chitin make up?

Answer 22

makes up fungal walls and exoskeleton of insects

Question 23

what does chitin contain?

Answer 23

nitrogen - 1 OH is replaced with N -acetyl group

Question 24

how is the polysaccharide structured?

Answer 24

2 beta-glucose, 1,4 bonds and flips 180 degrees so the hydrogen can be formed

Question 25

what does the polysaccharide glycogen do?

Answer 25

stores glucose in animals

Question 26

how is glycogen?

Answer 26

more branches - extremely compact so its good for respiration. 1,4 and 1,6 bonds

Question 27

what is meant by a reducing sugar. give 3 examples.

Answer 27

able to give away an electron - glucose, galactose fructose , maltose and lactose

Question 28

what is the test for reducing sugars?

Answer 28

add Benedict substance and heat
positive = red
negative =blue/green

Question 29

what is an example of a non-reducing sugar?

Answer 29

sucrose

Question 30

how do you test for non-reducing sugars?

Answer 30

add hcl acid, neutralise with hydrogen carbonates - repeat Benedict’s test and heat

Question 31

how would you test for protein?

Answer 31

biuret solution
positive = purple
negative= no colour change

Question 32

how do you test for lips (fats and oils)?

Answer 32

mixed with ethanol and shake

postive = cloudy white emulsion