B3.biological molecules

Question 1

list the chemical elements that make up lipids, carbohydrates and proteins

Answer 1

they all have carbon , oxygen and hydrogen but proteins also consist of nitrogen and sulphur

Question 2

what are carbohydrates made of

Answer 2

glucose, starch

Question 3

what are proteins made of

Answer 3

amino acid

Question 4

what are lipids made of

Answer 4

fatty acids, glycerol

Question 5

state what the iodine test is for and it’s potential results if positive or negative

Answer 5

for starch
if + blue/ black
if - orange/brown

Question 6

state what the biuret test is for and it’s potential results if positive or negative

Answer 6

protein
if+ mauve
if - light blue

Question 7

state what the Benedict test is for, the conditions to make it work and it’s potential results if positive or negative

Answer 7

for reducing sugar
needs to be heated
if + green-orange-red
if- deep blue

Question 8

state what the ethanol test is for, the conditions to make it work and it’s potential results if positive or negative

Answer 8

for lipids
you need to dissolve the food in ethanol then pour it in the water
if + cloudy
if - clear

Question 9

define what are enzymes

Answer 9

proteins that act like biological catalysts

Question 10

state the effect of temperature on enzyme activity

Answer 10

increased sped up movements of enzymes and substrates
increased product formation
there’s an optimum temperature for each of them
if the temperature increases significantly if causes the enzyme to change shape because it vibrates so much that the substrate can no longer fit so the enzyme becomes denatured/ dead

Question 11

define the effect of PH on enzyme activity

Answer 11

can cause enzymes to denature

can lower the activity therefore the rate of product formation