Final Flashcards
1
Q
Is measuring liquids in small amounts by mass or volume preferable in a typical home kitchen? Why?
A
Volume is preferable because small amounts of liquid are difficult to weigh precisely.
2
Q
For powders (e.g., sugar, flour) in small amounts, is mass or volume preferable? Why?
A
Mass is preferable because volume measurements can vary due to packing and settling.
3
Q
For non-sticky liquids, is mass or volume typically used for measurement?
A
Volume is typically used, as it is easier to pour and measure.
4
Q
For sticky liquids (e.g., honey), is mass or volume preferable? Why?
A
Mass is preferable because sticky liquids can be difficult to transfer completely from a measuring container.
5
Q
For powders in large amounts, is mass or volume preferable? Why?
A
Mass is preferable because it ensures accuracy and consistency.
6
Q
What property of an object determines whether it sinks or floats in a fluid?
A
The density of an object compared to the fluid determines whether it sinks or floats.
7
Q
In cooking, why does oil float on water?
A
Oil floats on water because it is less dense.
8
Q
What is the scientific notation for kilometer (km)?
A
10^3 m.
9
Q
What is the scientific notation for centimeter (cm)?
A
10^−2 m.
10
Q
What is the scientific notation for millimeter (mm)?
A
10^−3 m.
11
Q
What is the scientific notation for micrometer (µm)?
A
10^−6 m.
12
Q
What is the scientific notation for nanometer (nm)?
A
10^−9 m.
13
Q
What is the scientific notation for picometer (pm)?
A
10^−12 m.
14
Q
What is the scientific notation for gigameter (Gm)?
A
10^9 m.
15
Q
Name three commonly used brands of salt in cooking.
A
- Morton
- Diamond Crystal
- Celtic Sea Salt
16
Q
Why are common salt brands not interchangeable in recipes?
A
Due to differences in crystal size and density.
17
Q
What should you do when reading a recipe regarding salt?
A
Check the type of salt specified and adjust the amount to match the salt’s density if substituting.
18
Q
What does temperature represent at the molecular level?
A
Temperature is a measure of the average kinetic energy of molecules.
19
Q
What is the boiling water temperature at sea level in Celsius and Kelvin?
A
100°C (or 373 K).
20
Q
What is the temperature of ice water at sea level in Celsius and Kelvin?
A
0°C (or 273 K).
21
Q
What is the temperature difference between boiling water and ice water in Celsius and Kelvin?
A
100°C (or 100 K).
22
Q
What subatomic particles make up a typical atom?
A
- Protons
- Neutrons
- Electrons
23
Q
Which subatomic particle determines the element’s identity?
A
Protons.
24
Q
What contributes to atomic mass but not charge?
A
Neutrons.
25
Which subatomic particle determines the charge of an atom?
Electrons.
26
How many electrons complete the 1st, 2nd, and 3rd orbitals?
* 1st shell: 2 electrons
* 2nd shell: 8 electrons
* 3rd shell: 8 electrons (for main-group elements)
27
How do atoms form molecules?
By sharing (covalent bonding) or transferring (ionic bonding) electrons to complete their outer shells.
28
In the CO₂ molecule, how many valence electrons does carbon share with each oxygen?
2 electrons.
29
What is an ionic bond?
An ionic bond forms when electrons are transferred from one atom to another, creating ions that attract due to opposite charges.
30
In sodium chloride (NaCl), what happens to sodium and chlorine during ionic bonding?
Sodium loses one electron to form Na+ and chlorine gains one electron to form Cl−.
31
What are the defining features of organic molecules?
Contain carbon and usually hydrogen, oxygen, and nitrogen, often have covalent bonds.
32
What is the source of most organic molecules on Earth?
Photosynthesis.
33
What is the equation for photosynthesis?
6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂.
34
How many carbon, oxygen, nitrogen, and hydrogen atoms are in an organic molecule?
Depends on its molecular formula.
35
What defines an alkane?
Composed of only carbon and hydrogen with single bonds.
36
What defines an alcohol?
Contains a hydroxyl (-OH) group attached to a carbon.
37
What defines a carboxylic acid?
Contains a carboxyl (-COOH) group, with both a carbonyl (C=O) and hydroxyl (-OH) group.
38
What does 'pH' represent?
The concentration of hydrogen ions (H⁺) in a solution.
39
What is the equation for pH?
pH = -log[H⁺].
40
How do we define an 'acid'?
A substance that donates protons (H⁺).
41
How do we define a 'base'?
A substance that accepts protons (H⁺).
42
What happens when sodium bicarbonate reacts with hydrochloric acid in water?
Produces carbon dioxide gas (CO₂), salt (NaCl), and water (H₂O).
43
What do the terms 'polar' and 'non-polar' refer to?
Polar molecules have an unequal distribution of electrons; non-polar molecules have equal electron sharing.
44
What is electronegativity?
A measure of an atom’s ability to attract electrons in a bond.
45
Why is water (H₂O) considered a polar molecule?
Oxygen has higher electronegativity than hydrogen, creating partial charges.
46
Why is oxygen gas (O₂) considered non-polar?
Both O atoms have equal electronegativity, leading to equal electron sharing.
47
What are the five established tastes?
* Sweet
* Sour
* Salty
* Bitter
* Umami
48
What kind of molecules does the sweet taste respond to?
Sugars and some amino acids.
49
What kind of molecules does the sour taste respond to?
Hydrogen ions (H⁺) in acids.
50
What kind of molecules does the salty taste respond to?
Sodium ions (Na⁺) and other salts.
51
What kind of molecules does the bitter taste respond to?
Alkaloids and some amino acids.
52
What kind of molecules does the umami taste respond to?
Glutamate and nucleotides.
53
What are the three common monosaccharides?
* Glucose (C₆H₁₂O₆)
* Fructose (C₆H₁₂O₆)
* Galactose (C₆H₁₂O₆)
54
Which monosaccharide is the crucial energy source for almost all life on Earth?
Glucose.
55
What are the three main disaccharides?
* Sucrose (table sugar)
* Lactose (milk sugar)
* Maltose (malt sugar)
56
Which monosaccharides combine to produce sucrose?
Glucose + Fructose.
57
Which monosaccharides combine to produce lactose?
Glucose + Galactose.
58
Which monosaccharides combine to produce maltose?
Glucose + Glucose.
59
Which disaccharide is most commonly used to store energy in plants?
Sucrose.
60
How many common amino acids exist in proteins? *
20 common amino acids.
61
What distinguishes an amino acid?
Contains an amino (-NH₂) group, a carboxyl (-COOH) group, and a unique side chain (R group).
62
What are essential amino acids?
Amino acids that cannot be made by the body and must come from the diet.
63
What are non-essential amino acids?
Amino acids that can be synthesized by the body.
64
What is the relationship between amino acids and proteins?
Proteins are polymers of amino acids.
65
How do proteins form? *
Amino acids link via peptide bonds to form a polypeptide chain, which folds into multiple strands (combined into one complex).
66
What are the characteristics of a saturated fatty acid?
Contains only single bonds between carbon atoms and tends to be solid at room temperature.
67
What are the characteristics of an unsaturated fatty acid?
Contains one or more double bonds and tends to be liquid at room temperature.
68
What are triglycerides?
The main form of fat in foods and the body, composed of three fatty acids bonded to a glycerol backbone.
69
How are triglycerides made?
Formed via esterification when fatty acids react with glycerol.
70
Give examples of foods rich in saturated fats.
* Butter
* Coconut oil
71
Give examples of foods rich in unsaturated fats.
* Olive oil
* Salmon
72
What are the four main constituents of air on Earth?
* Nitrogen (N₂) ~78%
* Oxygen (O₂) ~21%
* Argon (Ar) ~0.93%
* Carbon dioxide (CO₂) ~0.04%
73
Name three important greenhouse gases.
* Carbon dioxide (CO₂)
* Methane (CH₄)
* Water vapor (H₂O)
74
What is one important source of carbon dioxide (CO₂) on Earth?
Burning fossil fuels.
75
How is pressure related to force?
Pressure (P) is force (F) applied over an area (A): P = F/A.
76
What are the units of pressure?
* Pascals (Pa)
* Atmospheres (atm)
* mmHg or Torr
77
What is atmospheric pressure responsible for?
The weight of air above us.
78
Why are we not crushed by atmospheric pressure?
The pressure inside our bodies counterbalances it.
79
Give the equation for the ideal gas law.
PV = nRT.
80
What does each symbol in the ideal gas law represent?
* P = pressure
* V = volume
* n = number of moles of gas
* R = universal gas constant
* T = temperature (Kelvin)
81
How can the ideal gas law be applied to making popcorn?
Heating water inside kernels increases pressure, causing the kernels to pop.
82
How can the ideal gas law be applied to baking a scone?
Baking soda releases CO₂ gas, causing the dough to expand.
83
Why is baking soda a common ingredient in baked goods?
It reacts with an acid to produce CO₂, which leavens dough.
84
What is the difference between baking powder and baking soda?
Baking powder contains both baking soda and a dry acid, activating when moistened.
85
What is viscosity?
A liquid’s resistance to flow.
86
Why is viscosity important for food?
It controls mouthfeel and texture.
87
What determines how viscous a (pure) liquid is at the molecular level?
Stronger intermolecular forces result in higher viscosity.
88
Why is viscosity important for food?
Controls mouthfeel and texture, thick soups, sauces, and syrups rely on viscosity.
89
What determines the viscosity of a pure liquid at a molecular level?
Stronger intermolecular forces and larger molecules.
90
How do starch thickeners work?
Starch thickens by gelatinization, where heat causes starch granules to absorb water and swell.
91
What is the proper use of starch in a recipe?
Mix starch with cold liquid first to prevent clumping and heat gradually.
92
Define molecules, particles, and drops.
Molecules: Groups of atoms chemically bonded. Particles: Tiny pieces of matter. Drops: Liquid clusters held by surface tension.
93
How do molecules interact with visible light?
Transparent if small (e.g., water).
94
What is brittleness?
How easily a solid breaks when force is applied.
95
Provide an example of a very brittle food.
Crackers.
96
What is toughness?
How resistant a material is to breaking.
97
Provide an example of a very tough food.
Beef jerky.
98
Define hardness.
Resistance to being scratched or indented.
99
Provide an example of a very hard food.
Rock candy.
100
Define elasticity.
Ability to return to its original shape after deformation.
101
Provide an example of a very elastic food.
Mozzarella cheese.
102
What is sensible heat energy?
Heat energy that causes a temperature change in a substance.
103
What is the equation for calculating sensible heat energy?
Q=mcΔT.
104
What does each symbol represent in the equation Q=mcΔT?
Q = heat energy (Joules), m = mass (kg), c = specific heat capacity (J/kg·K), ΔT = change in temperature (K or °C).
105
What is latent heat energy?
Energy required for a substance to change phase without a temperature change.
106
What is the equation for calculating latent heat energy?
Q=mL.
107
What does each symbol represent in the equation Q=mL?
Q = heat energy (J or cal), m = mass (g or kg), L = latent heat (J/g or cal/g).
108
List the six different phase changes possible for water.
* Melting (solid → liquid) * Vaporization (liquid → gas) * Sublimation (solid → gas) * Freezing (liquid → solid) * Condensation (gas → liquid) * Deposition (gas → solid)
109
What phase changes require energy?
* Melting * Vaporization * Sublimation
110
What phase changes release energy?
* Freezing * Condensation * Deposition
111
How does evaporation depend on temperature?
Evaporation increases as temperature rises.
112
What is the difference between evaporation and boiling?
Evaporation occurs at any temperature at the surface; boiling happens at a specific temperature throughout the liquid.
113
What happens to the temperature of boiling water?
The temperature remains constant as energy is used to convert liquid into vapor.
114
What happens when water freezes?
Water expands (~9%) and forms a rigid hydrogen bond structure.
115
What is flow?
A rate of movement over time.
116
What is amount?
A fixed quantity.
117
What is the difference between energy and power?
* Energy: Capacity to do work (Joules, J) * Power: Rate of energy transfer (Watts, W)
118
What is necessary for conduction to lead to the flow of energy?
Direct contact between molecules is required.
119
What materials are good conductors?
* Metals (e.g., copper, aluminum)
120
What materials are poor conductors?
* Wood * Plastic
121
What is carryover cooking?
Food continues to cook after removal from heat due to retained heat.
122
How can you prevent carryover cooking?
Remove food slightly before desired doneness and let it rest.
123
What is necessary for advection to lead to the flow of energy?
Fluid movement (air or liquid) must carry heat. Temperature Difference. DRAW - Ex: Coffee & Cream - Heat moves upwards (Hot->cold)
124
What three types of radiation does the sun emit?
* Ultraviolet (UV) radiation * Visible light * Infrared (IR) radiation
125
Which type of radiation is emitted by humans?
Infrared radiation.
126
What modes of heat transfer are important in a hot pizza oven?
* Conduction * Convention * Radiation
- Conduction happens through
- Hot air movement and cold pizza (temp def)
-
127
What does electronegativity of an atom refer to?
An atom’s tendency to attract electrons.
128
Why is electronegativity important?
Determines polarity and affects bond strength and reactivity.
129
What is caramelization?
Thermal breakdown of sugars producing complex flavors and browning.
130
What conditions are necessary for caramelization to occur?
Requires high heat (~170°C / 340°F) and no water present.
131
What are Maillard reactions?
Reactions between sugars and amino acids producing browning and flavor.
132
What conditions are necessary for Maillard reactions to occur?
Requires heat (~140-165°C) and low moisture conditions.
133
What are two advantages of wet cooking?
* Helps retain moisture * Gentle heat prevents burning
134
What are two disadvantages of wet cooking?
* Can cause nutrient loss * Does not create browning
135
What are two advantages of dry cooking?
* Creates rich flavors and browning * Develops a crispy texture
136
What are two disadvantages of dry cooking?
* Can dry out food * Requires careful heat control
137
What are the similarities between boiling, poaching, steaming, and braising?
All use moist heat for cooking.
138
What is the main difference between boiling and poaching?
Boiling uses rapid water circulation; poaching uses gentle heat.
139
What modes of heat transfer are relevant for boiling?
Convection.
140
What is the main difference between sauté/pan fry and stir fry?
Sautéing uses a small amount of fat; stir frying uses higher temperatures with constant movement.
141
What is the standard term for a 'solid solution'?
Alloy.
142
What determines whether a solute has high or low solubility?
* Temperature * Polarity * Pressure
143
What is solubility?
Maximum amount of solute that can dissolve in a solvent at a given temperature.
144
What are the three terms used to describe a solution based on solute content?
* Unsaturated * Saturated * Supersaturated
145
What is a continuous phase in a colloid?
The substance in which another is dispersed.
146
What is a dispersed phase in a colloid?
The phase distributed within the continuous phase.
147
Provide an example of an emulsion.
Mayonnaise.
148
What is an unstable emulsion?
Droplets separate over time.
149
What do hydrophilic and hydrophobic mean?
* Hydrophilic: Water-loving * Hydrophobic: Water-fearing
150
What are emulsifiers?
Amphiphilic molecules that stabilize emulsions.
151
What are two main sources of emulsifiers used in recipes?
* Egg yolk (lecithin) * Milk proteins
152
How do stabilizers work in emulsions?
They increase viscosity to slow movement and prevent phase separation.
153
List three common stabilizers used in recipes.
* Gums (e.g., xanthan gum) * Pectin (e.g., in jams) * Gelatin
154
What is the purpose of stabilizers in emulsions?
Prevent coalescence by increasing viscosity
## Footnote
Stabilizers work by slowing movement and preventing phase separation.
155
Name three common stabilizers used in recipes.
* Gums (e.g., xanthan gum)
* Pectin (e.g., in jams)
* Gelatin (e.g., in dairy products)
156
What is agglomeration?
Clustering of dispersed droplets leading to instability
## Footnote
It affects the stability of an emulsion.
157
What factors can increase agglomeration?
* Large droplet size
* Low emulsifier concentration
* High temperature
158
What factors can decrease agglomeration?
* Small droplets
* High emulsifier concentration
* Low temperature
159
What is sedimentation?
Settling of dispersed particles due to gravity
## Footnote
It can cause emulsion separation.
160
What main factor can increase sedimentation?
Density difference between phases
## Footnote
Higher density contrast leads to faster sedimentation.
161
What is PM2.5?
Particulate matter ≤2.5 µm (fine particles)
162
What is PM10?
Particulate matter ≤10 µm (coarse particles)
163
Why does the US EPA regulate PM2.5 and PM10?
They penetrate deep into the lungs, causing respiratory and cardiovascular diseases (DEATH)
164
Define AQI.
Air Quality Index, a standardized scale measuring air pollution levels
165
Why is the AQI useful?
Helps the public assess health risks from air pollution
166
What is the AQI for PM2.5 if the outdoor concentration is 18 µg/m³?
Slightly above moderate (51-100), indicating possible risk for sensitive groups
167
What is one piece of advice for reducing PM2.5 in the home?
Use an air purifier
## Footnote
It removes fine particles from indoor air.
168
What is another piece of advice for reducing PM2.5?
Avoid burning candles or smoking indoors
169
What is a third piece of advice for reducing PM2.5?
Ventilate when cooking
170
What technological advancements have helped grow enough food for the current population?
* Green Revolution
* Mechanized farming
* Genetically Modified Organisms (GMOs)
171
Why are nitrogen (N) and phosphorus (P) critical in fertilizers?
* Nitrogen: Essential for proteins and DNA
* Phosphorus: Important for ATP and root development
172
What is the Haber-Bosch process?
Converts atmospheric nitrogen (N₂) into ammonia (NH₃) using high temperature and pressure
173
Where does phosphorus in fertilizer come from today?
Phosphate rock mining
174
How did Europeans acquire phosphorus in the 1800s?
Guano (bird droppings) from islands
175
What is one negative environmental impact of excess fertilizer use?
Eutrophication leading to algae blooms
176
What is another negative impact of excess fertilizer use?
Soil degradation altering soil chemistry
177
What is a third negative impact of excess fertilizer use?
Greenhouse gas emissions (N₂O from fertilizers)
178
What is the average water use per person in the US?
~300-400 gallons per day
179
What percentage of total water use in the US is for agriculture?
~70-80%
180
What percentage of total water use in the US is for homes?
~10-15%
181
What is an advantage of flow-based water sources?
Constant replenishment
## Footnote
Example: Rivers
182
What is a disadvantage of flow-based water sources?
Can dry up due to droughts
183
What is an advantage of amount-based water sources?
Stores large volumes for use during droughts
## Footnote
Example: Reservoirs
184
What is a disadvantage of amount-based water sources?
Limited total supply
185
What is groundwater?
Water stored underground in soil and rock layers
186
What are the two main types of groundwater?
* Unconfined aquifers
* Confined aquifers
187
How do unconfined aquifers differ from confined aquifers?
* Unconfined: Directly connected to the surface
* Confined: Trapped between layers of impermeable rock
188
What is virtual water?
Hidden water used to produce goods and food
189
How can virtual water reduce water stress?
* Shift to less water-intensive crops
* Import food from water-rich regions
* Reduce food waste
190
Why is soil moisture important for agriculture?
Essential for crop growth, root health, and nutrient uptake
191
What are the two main processes that affect soil moisture?
* Evaporation
* Transpiration
192
How does climate change impact evaporation?
Higher temperatures increase evaporation
193
What happens to insects as outdoor temperatures increase?
Faster life cycles leading to more pests
194
What happens to plants as outdoor temperatures increase?
Heat stress reduces yields
195
What is the effect of increased CO₂ concentrations on crops?
* Increased carbohydrate content
* Decreased protein, iron, and zinc levels
196
What kinds of molecules produce the sour taste?
Acids (e.g., citric acid, acetic acid)
197
Why is detecting sourness in food important?
* Helps identify spoiled food
* Enhances flavor balance
198
What kinds of molecules produce the sweet taste?
Sugars and some amino acids (e.g., glucose, fructose)
199
Why is detecting sweetness in food important?
Indicates energy-rich foods
200
What kinds of molecules produce the salty taste?
Ionic salts (e.g., sodium chloride)
201
Why is detecting saltiness in food important?
* Maintains electrolyte balance
* Enhances flavor
202
What kinds of molecules produce the bitter taste?
Alkaloids, some peptides, and plant polyphenols (e.g., caffeine, quinine)
203
Why is detecting bitterness in food important?
Warning signal for potentially toxic compounds
204
What kinds of molecules produce the umami taste?
Glutamates and nucleotides (e.g., MSG)
205
Why is detecting umami in food important?
Enhances savory richness in foods
206
What are the three main categories of sugars?
* Monosaccharides
* Disaccharides
* Polysaccharides
207
Name three food-related molecules in monosaccharides.
* Glucose
* Fructose
* Galactose
208
Name three food-related molecules in disaccharides.
* Sucrose
* Lactose
* Maltose
209
Name three food-related molecules in polysaccharides.
* Starch
* Cellulose
* Glycogen
210
Which sugar is most important for bodily function?
Glucose
211
What are fatty acids?
Hydrocarbon chains with a carboxyl (-COOH) group at one end
212
What is the relationship between fatty acids and fats?
Fatty acids are building blocks of triglycerides
213
What are trans fats?
Unsaturated fats with at least one trans double bond
214
Why are trans fats a concern for human health?
* Increase LDL
* Decrease HDL
* Increase risk of heart disease
215
What is the difference between saturated and unsaturated fats?
* Saturated: No double bonds, solid at room temperature
* Unsaturated: One or more double bonds, liquid at room temperature
216
What is protein denaturation?
Unfolding of a protein's structure causing loss of function
217
What can cause protein denaturation?
* Heat
* pH changes
* Mechanical action
218
What is coagulation in proteins?
Formation of solid or semi-solid structures from denatured proteins
219
What are enzymes?
Proteins that catalyze chemical reactions
220
What role do enzymes play in food science?
* Tenderizing meat
* Cheese-making
* Ripening fruit
221
What is fermentation?
Metabolic process where microorganisms break down sugars into acids, gases, or alcohol
222
What are probiotics?
Live beneficial bacteria that support gut health
223
What are prebiotics?
Non-digestible fibers that feed probiotics
224
What is pasteurization?
Heat treatment used to kill pathogenic bacteria in food
225
Why is pasteurization important?
* Extends shelf life
* Prevents foodborne illness
226
What are foodborne illnesses?
Diseases caused by consuming contaminated food
227
What are the main causes of foodborne illnesses?
* Bacteria
* Viruses
* Toxins
228
What is food spoilage?
Deterioration in food quality due to microbial, chemical, or physical changes
229
How does food spoilage differ from foodborne illness?
Spoilage affects quality but may not cause illness; foodborne illness results from harmful pathogens
230
What are antioxidants?
Compounds that slow oxidation, preventing food spoilage
231
How do antioxidants help preserve food?
* Prevent rancidity in fats
* Protect color and flavor
232
What are food additives?
Substances added to food to improve quality, flavor, or shelf life
233
Name some common categories of food additives.
* Preservatives
* Colorants
* Emulsifiers
* Flavor enhancers
