Enzymes structure and functionality

Question 1

actions that can disrupt the structure of food and impact the functionality of enzymes

Answer 1

cutting, peeling, mashing, pureeing, mastication

Question 2

how does physcial disruption affect enzyme activity

Answer 2

enzymes that arent found with thier substrate in the food matrix can interact

Question 3

example enzyme in cabbage

Answer 3

myrosinase
-also found in the gut

Question 4

function of myrosinase

Answer 4

hydrolysis of glucosinates

Question 5

where is myrosinase found

Answer 5

cell wall

Question 6

where are glucosinates found

Answer 6

inside plant cells

Question 7

what reaction occurs between myrosinase and glucosinolates

Answer 7

hyrolysis

Question 8

what does the hydrolysis of hydrosinolates produce

Answer 8

glucose + active products
-isothiocynaat
-nitrill
-thiocyanaat

Question 9

what do active products supply

Answer 9

health benefit
sensory atributes (sulphuric smell)

Question 10

how can you stop the action of myrosinase

Answer 10

cook it

Question 11

co factor for myrosinase

Answer 11

vitamin C

Question 12

role of ascorbic acid in food

Answer 12

regulate redox balance inside the cell

Question 13

what enzyme regulates ascorbic acid

Answer 13

ascorbic acid oxidase

Question 14

product from L-ascorbic acid oxidation

Answer 14

dehydroxyascorbic acids (DHAA)

Question 15

oxidising agents for LAA

Answer 15

AAO (ascorbic acid oxidase)
light
heat
oxygen
pH
metal ions

Question 16

two types of oxidation that can happen to LAA

Answer 16

enzymatic
chemical

Question 17

describe the active site of AAO

Answer 17

multicopper oxidase glycoprotein

Question 18

function of AAO

Answer 18

control cell growth
indirectly control L-AA pool

Question 19

what effects AAO

Answer 19

light
temperature
oxygen
pH
maturity

Question 20

where is AAO found

Answer 20

bound to the cell wall

Question 21

where is L-AA found

Answer 21

cytosol
vacuole
cell wall
organelle

Question 22

why is there less DHAA in leaves that have received higher heat treatment

Answer 22

the heat inactivates AAO so less conversion is occuring

Question 23

optimal pH for AAO

Answer 23

around 6

Question 24

optimal pH of pectinase

Answer 24

around 6

Question 25

temperature AAO will inactivate/denature

Answer 25

70-80C

Question 26

when frozen carrots are cooked what is the best temperature to maintain the vitamin C content

Answer 26

20-30
lower is better