Changing properties- proteins pg28

Question 1

when do proteins denature

Answer 1

during preparation and cooking

Question 2

what structure do proteins have

Answer 2

-a complex structure
-when foods cooked proteins denature, meaning the chemical bonds that hold the structure together break down

Question 3

Name 3 ways proteins can denature

Answer 3

-physical agitation (whisking, beating, kneading)
-changes in temperature (heat)
-acids (lemon juice)

Question 4

what do denatured protein molecules do

Answer 4

coagulate

Question 5

State what happens after proteins denature

Answer 5

protein molecules collide with other protein molecules and coagulate (join together)

Question 6

State what happens after proteins denature
-what happens during then this process

Answer 6

-water becomes trapped between the protein molecules.

Question 7

what does coagulation do to foods

Answer 7

-changes the appearance and texture of food
-e.g egg white turns from a see-through liquid into a white solid

Question 8

what is formed when air is trapped

Answer 8

foams

Question 9

what are foams formed by

Answer 9

when air is trapped
-when gas becomes trapped (aeration) inside a liquid

Question 10

state what happens when an egg white is whisked

Answer 10

the proteins inside the liquid denature
-causing them to stretch and air becomes trapped in the liquid

Question 11

what does gluten do

Answer 11

allows doughs to stretch and rise

Question 12

what is gluten and where is it formed

Answer 12

-glutens found in wheat flours (wheat, barley)
-formed when waters mixed with flour to make the dough
-in foods bread, pasta, cakes and pastries

Question 13

what causes gluten strands to strengthen

Answer 13

kneading the dough

Question 14

what happens when gluten reaches a high temperature

Answer 14

-it coagulates and the dough stays stretched
-giving food a light, airy texture
-e.g bread