B4 - Biological molecules

Question 1

types of digestive enzymes

Answer 1

protease enzymes - pepsin (stomach) and trypsin (duodenum)
amylase (saliva and pancreatic)
lipase

Question 2

describe enzymes

Answer 2

proteins that are involved in all metabolic reactions, where they function as biological catalysts

Question 3

enzyme activity parts (5)

Answer 3

enzyme
substrate
enzyme-substrate complex
active site
product

Question 4

describe the test for starch (3)

Answer 4

add iodine
positive test is colour turns blue-black
negative test is colour stays yellow-brown

Question 5

describe the test for reducing sugars (4)

Answer 5

add Benedict’s solution
heat solution
positive test is colour turns green-yellow-orange-brick red
negative test is colour stays blue

Question 6

describe the test for protein (5)

Answer 6

called the biuret test
add potassium hydroxide to make solution alkaline
add copper sulfate
positive test is colour turns purple
negative test is colour stays blue

Question 7

describe the test for lipids

Answer 7

called the ethanol emulsion test
shake substance with ethanol
pour solution into water
positive test is solution precipitates and shows up at the top as a milky emulsion
negative test is no cloudy emulsion formed at the top