Enzymes structure and functionality Flashcards

1
Q

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

A

cutting, peeling, mashing, pureeing, mastication

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2
Q

how does physcial disruption affect enzyme activity

A

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

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3
Q

example enzyme in cabbage

A

myrosinase
-also found in the gut

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4
Q

function of myrosinase

A

hydrolysis of glucosinates

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5
Q

where is myrosinase found

A

cell wall

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6
Q

where are glucosinates found

A

inside plant cells

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7
Q

what reaction occurs between myrosinase and glucosinolates

A

hyrolysis

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8
Q

what does the hydrolysis of hydrosinolates produce

A

glucose + active products
-isothiocynaat
-nitrill
-thiocyanaat

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9
Q

what do active products supply

A

health benefit
sensory atributes (sulphuric smell)

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10
Q

how can you stop the action of myrosinase

A

cook it

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11
Q

co factor for myrosinase

A

vitamin C

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12
Q

role of ascorbic acid in food

A

regulate redox balance inside the cell

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13
Q

what enzyme regulates ascorbic acid

A

ascorbic acid oxidase

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14
Q

product from L-ascorbic acid oxidation

A

dehydroxyascorbic acids (DHAA)

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15
Q

oxidising agents for LAA

A

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

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16
Q

two types of oxidation that can happen to LAA

A

enzymatic
chemical

17
Q

describe the active site of AAO

A

multicopper oxidase glycoprotein

18
Q

function of AAO

A

control cell growth
indirectly control L-AA pool

19
Q

what effects AAO

A

light
temperature
oxygen
pH
maturity

20
Q

where is AAO found

A

bound to the cell wall

21
Q

where is L-AA found

A

cytosol
vacuole
cell wall
organelle

22
Q

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

A

the heat inactivates AAO so less conversion is occuring

23
Q

optimal pH for AAO

A

around 6

24
Q

optimal pH of pectinase

A

around 6

25
Q

temperature AAO will inactivate/denature

A

70-80C

26
Q

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

A

20-30
lower is better