biological molecules and enzymes

Question 1

Define biological moelcule

Answer 1

organic molecules found in living things

Question 2

What are the chemicals that make up carbohydrates (3)

Answer 2

carbon

hydrogen

oxygen

Question 3

Define carbohydrates

Answer 3

molecules made up of small basic units called simple sugars

Question 4

Define starch

Answer 4

energy storage molecule in plants

Question 5

Define glycogen

Answer 5

energy storage in animals

Question 6

Define protein

Answer 6

complex biological macromolecule made up of amino acid monomers, that can have a wide variety of forms and functions

Question 7

What chemical elements do amino acids/proten consist of (4)

Answer 7

carbon

hydrogen

oxygen

nitrogen

Question 8

Define lipids

Answer 8

Macromolecules consisting of glycerol and fatty acids

Question 9

what chemical elements do lipids consist of (3)

Answer 9

carbon

hydrogen

oxygen

Question 10

Which simple sugar is used to form starch and glycogen

Answer 10

glucose monosaccharides

Question 11

Which chemical to use to test for reducing sugars

Answer 11

Benedict’s solution

Question 12

Colour change for positive reaction for reducing sugars

Answer 12

blue to orange-red

Question 13

Which chemical to use to test for starch

Answer 13

iodine solution

Question 14

Colour change for positive reaction for starch

Answer 14

brown to dark blue black

Question 15

Which chemical to use to test for proteins

Answer 15

Biuret reagent

Question 16

Colour change for positive reaction for proteins

Answer 16

blue to purple

Question 17

Which chemicals to use to test for lipids

Answer 17

ethanol and distilled water

Question 18

Colour change for positive reaction for lipids

Answer 18

clear to milky white cloudy EMULSION

Question 19

Water has properties that makes it a good solvent.

True or False

Answer 19

true

Question 20

Define enzymes

Answer 20

proteins tht function as biological catalyst

Question 21

Explain enzyme action (5)

Answer 21

Each type of enzyme has a unique active site to which a specific substrate can bind

The shape of active site is COMPLEMENTARY to its substrate

substrate fits into enzyme

enzyme substrate complex formed

products may have formed (Bond of substrate broken under stress) or substrates combined into one product

Question 22

Define a catalyst (generallly)

Answer 22

a substance that increases the rate of reaction without being changed or used up in the process

Question 23

Define a substrate

Answer 23

molecule enzyme binds to at start of reaction

Question 24

Enzymes are specific and unique

True or false

Answer 24

true

Question 25

Explain the effect of temperature on enzyme activity (5)

Answer 25

As temperature increases, molecules gain more kinetic energy and move faster

Increase in the frequency of effective collisions between substrate and enzyme active sites

The rate of enzyme catalysed reactions increases up to the optimum temperature

beyond optimum temperature, enzyme molecule vibrate so mcuh that they start to change the shape of the active site (denaturation)

Rate of reaction decreases as the active site is no longer complementary to the substrate

Question 26

Effect of pH on enzyme acitvity (3)

Answer 26

Enzymes have an optimum pH at which the rate of enzyme catalysed reaction is highest

A change of pH on either side of the optimum pH results in a change in shape of the enzyme’s active site

Causes denauration (active site no longer complementary)