Chapter 4 - Proteins And Enzymes

Question 1

What are proteins?

Answer 1

Long chains of amino acids called polypeptide chains (chained together by ribosomes during protein synthesis)

Question 2

Define catabolic and anabolic?

Answer 2

Catabolic: breaks down chemicals

Anabolic: builds up chemicals

Question 3

What are some uses of enzymes?

Answer 3

1. Alcohol: yeasts break down sugars into alcohol
2. Bread: yeasts break down sugars and alcohol to make it rise
3. Cheese: enzymes break down into curd and whey
4. Washing powder: enzymes break down grease and dirt (between 30 & 40•C)

Question 4

What is denaturation and when does it occur?

Answer 4

When the enzymes change shape so can’t work- occurs when the pHs or temperatures aren’t right

Question 5

What does hydrochloric acid do?

Answer 5

1. Sterilised the food and kills bad pathogens that can make you ill
2. Breaks down protein

Question 6

What do bile salts do and where are they from?

Answer 6

Produced in liver & released by gall bladder into small intestine

1. Emulsifies fats (turns blobs into droplets)
2. Increases surface area

Question 7

What is the use of enzymes in a fermenter?

Answer 7

Grows population of bacteria to produce enzymes

Question 8

What is required in a fermenter for the optimum to be reached?

Answer 8

1. Temperature: 37• depending on bacteria
2. Oxygen levels
3. Moisture levels
4. Nutrition growth medium

Question 9

Special properties of enzymes?

Answer 9

1. Able to stand fairly high temperatures
2. Long shelf life
3. Able to work in presence of chemicals which usually stop them working
4. Wider pH tolerance