Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FDSC200 > lecture-chapter5 > Flashcards

lecture-chapter5 Flashcards

1
Q

what is energy?

A

ability to do work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does food scientists examine? what does it help?

A

how heat is transferred during cooking and preservation and how energy affects the structure of food during such processes. –help develop new food products to meet the needs of consumers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how can energy be describe?

A

stored or motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is potential energy?

A

stored energy. e.g. work done in lifting objects to a position. in food, it is in the form of chemical potential energy called calories.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is kinetic energy?

A

the energy of motion. the faster an object moves, the more kinetic energy it has.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what energy does atoms and molecules always have?

A

kinetic energy, because they are always in motion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how does energy constantly change?

A

from potential to kinetic energy and back again.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how can Potential and kinetic energy be described?

A

as external or internal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is external energy?

A

Energy applied to an object by another source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is internal energy?

A

Energy within an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does food contain?

A

internal potential energy–fuel for the body is stored in every piece of food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is energy’s property?

A

versatile多用途的 and can change from one form to another.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what forms of energy are used by the food industry?

A

all forms. mechanical, chemical, electrical, nuclear, radiant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is mechanical energy?

A

total kinetic and potential energy of a system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is mechanical energy used by?

A

the body whenever it moves. equipment during food processing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what energy does mixers, blenders and food processors convert to?

A

electrical energy to mechanical energy.– performs work on food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

when is chemical energy generate?

A

bonds between atoms are forms or broken during chemical reactions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does endothermic reaction do?

A

absorbs or stores energy and lowers the temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what does exothermic reaction do?

A

releases energy and increases the temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what does metabolism do?

A

allow body to utilize chemical energy from food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how does electrical energy produce?

A

movement of e-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what can electrical energy do?

A

efficiently converted into mechanical or radiant energy for food processing. transported through materials that are good conductors such copper, silver, and certain metals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is radiant energy?

A

energy transmitted in the form of waves through space or some medium.–electromagnetic spectrum is another term.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what will it call when visible?

A

light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

when radiant energy is used?

A

cooking appliances and outdoor grills.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what energy does microwave change?

A

convert electrical energy to radiant energy. the electron tube converts electrical energy into microwaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is magnetron?

A

the electron tube.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is microwaves?

A

low-frequency electromagnetic waves of radiant energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how does microwave work?

A

interior surfaces reflect microwaves toward the food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what does induction cooktops use electromagnetic waves do?

A

generate heat during cooking.–special pans with metals that react to a magnetic field produce the electric current needed to cook food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is nuclear energy?

A

the result of splitting or combining atoms of certain elements, which then give off radiation

32
Q

what is nuclear energy used to? 3 ways.

A

– in medicine for x-rays – in food preservation such as irradiation放射性照射 – by nuclear power plants to generate electricity

33
Q

what is heat?

A

an energy transfer from one body to another caused by a temperature difference between the 2 bodies

34
Q

how is food energy be measured?

A

in terms of the capacity to produce heat.

35
Q

what is one calorie?

A

the heat needed to raise the temp of one gram of water one degree celsius.

36
Q

what is a kilocalorie?

A

the amount of heat needed to raise the temperature of one kilogram of water one degree Celsius -it simplifies calorie counts.

37
Q

what is heat capacity?

A

the ability of a substance to absorb heat. food with high water content has a high heat capacity.

38
Q

what is specific heat?

A

the ability of a substance to absorb or transfer heat compared to water’s ability.

39
Q

what is specific heat?

A

It is the amount of energy needed to raise the temperature of 1 g of a substance 1 Celsius

40
Q

what does knowing a specific heat of food help?

A

help researchers predict how the food will react during processing.

41
Q

what is temp?

A

the measure of the average kinetic energy of a group of individual molecules.

42
Q

what is temp? 3 points.

A

-an indirect measure of molecular motion –measured by using a thermometer – important to ensure food safety and product quality

43
Q

how is heat movement?

A

from heat to cooler objects.

44
Q

what are the heat transfer methods?

A

conduction, convection and radiation.

45
Q

what is thermodynamics热力学?

A

a branch of physics, studies heat flow and temperature in relation to material properties

46
Q

what is conduction?

A

the transfer of heat through matter from particle to particle collisions

47
Q

when is conduction occur? how?

A

only in metals at the molecular level. heated e- skip over tens or hundreds of atoms and speed the heat transfer.

48
Q

what is convection?

A

the transfer of heat by the motion of molecules within a liquid or a gas, such as water or air

49
Q

when is convection occur?

A

as the temp increase, convection currents are generated that speed heating.

50
Q

what is the properties of convection? example

A

convection is faster than conduction. cooking food in water.

51
Q

what is radiation?

A

the transfer of heat by electromagnetic waves. it does not need the presence of matter.

52
Q

what does radiation cause? what are the example?

A

cause most of the browning of baked and roasted foods. broiling烤 and rotisserie cooking.

53
Q

what is needed for phase change?

A

a flow of energy

54
Q

what is fusion or melting?

A

a substance move from a solid to liquid phase.

55
Q

what is crystallization?

A

a substance that moves from liquid to solid phase.

56
Q

what is the latent heat of fusion?

A

the energy needed to melt or freeze a substance.

57
Q

what is evaporation or vaporization?

A

a substance that moves from liquid to gaseous phase

58
Q

what is condensation or liquefaction?

A

a substance that moves from gas to liquid phase

59
Q

what is latent heat of vaporization?

A

the energy needed to evaporate or condense a substance

60
Q

what is the latent heat?

A

the energy needed to complete the rearranging of molecules during a phase change.

61
Q

what will the temp be at the point of a phase change?

A

temp remains constant.

62
Q

what is deposition?

A

change a substance from gas to solid phase.

63
Q

what is sublimation?

A

change a substance from solid to gas phase.

64
Q

understand phase change is important in __?

A

processing and preserving food products.

65
Q

what does phase changes need?

A

extra energy

66
Q

what happen to energy as temp drop?

A

energy release.

67
Q

what happen to energy as temp climb?

A

energy absorbed.

68
Q

what are the factors that affect rates of reaction in food preparation?

A

-temp of reactants -amount of surface area -thickness of the food

69
Q

how temp of reactant affect rates of reaction in food preparation?

A

the rate of a reaction approximately doubles for every 10 degree increase in temp.

70
Q

how amount of SA affect rates of reaction in food preparation?

A

the greater the SA, the faster the reaction

71
Q

how thickness of the food affect rates of reaction in food preparation?

A

the thicker the food, the longer it will take to cook.

72
Q

what is potential energy?

A

stored energy and kinetic energy is the energy of motion

73
Q

what does various forms of energy include?

A

– mechanical energy – chemical energy – electrical energy – radiant energy – nuclear energy

74
Q

what is heat?

A

the measure of total kinetic energy of a substance

75
Q

what is temp?

A

the average kinetic energy of individual molecules

76
Q

how heat is transferred by?

A

– conduction – convection – radiation

77
Q

Rates of reaction in food preparation are affected by?

A

– temperature of the reactants – amount of surface area – thickness of the food

FDSC200 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions