Nutrition Flashcards
(160 cards)
1
Q
What element are food molecules based on?
A
Carbon
2
Q
What are the four ways carbohydrates are stored as?
A
- Sugars
- Starch
- Glycogen
- Cellulose
3
Q
What is the solubility characteristic of sugars?
A
All soluble in water
4
Q
What is the general process where complex organic molecules are broken down?
A
Digestion
This process involves the absorption of simpler molecules.
5
Q
What are catabolic pathways responsible for?
A
Digestion and Absorption
6
Q
What are anabolic pathways responsible for?
A
Assimilation
7
Q
What three elements are carbohydrates made of?
A
Carbon, Hydrogen and Oxygen
8
Q
What is the enzyme that breaks down starch into maltose?
A
Amylase
9
Q
What does maltase convert maltose into during digestion?
A
Glucose
10
Q
What is the role of starch in plants?
A
Glucose storage
11
Q
What is glycogen used for in animals?
A
Glucose storage
12
Q
What elements are proteins made of?
A
Carbon, hydrogen, nitrogen, and oxygen
13
Q
What are the subunits of proteins called?
A
Amino acids
There are 20 different types of amino acids.
14
Q
How does the sequence of amino acids in a protein affect its function?
A
Determines the protein’s unique shape
15
Q
What are lipids made of?
A
Glycerol attached to 3 fatty acids
16
Q
What elements do lipids primarily use?
A
Carbon, hydrogen, and oxygen
17
Q
What is the significance of the variety in fatty acids in lipids?
A
Leads to a large number of different lipid types
18
Q
What is the primary function of carbohydrates in the human body?
A
Provides energy for the body & brain
19
Q
What are the effects of carbohydrate deficiency?
A
Low BMI (body mass index)
20
Q
What is the role of protein in the human body?
A
Formation of bones, tissues, muscles, teeth, and skin
21
Q
What can result from protein deficiency?
A
Weakened immune system, slow growth
22
Q
List the functions of lipids in the human body.
A
- Regulation of hormones
- Transmitting nerve impulses
- Cushioning organs
- Storing energy as fat
23
Q
What are the effects of lipid deficiency?
A
Weight loss, dry skin, poor temperature regulation
24
Q
What is Vitamin C (Ascorbate) essential for?
A
- Healthy skin, Blood vessels, Bones
- Allergy protection
- Wound healing
- Iron absorption
25
What are the consequences of Vitamin C deficiency?
Weakened immune system, gums bleed, skin won't heal
26
What benefits does Vitamin A (Retinol) provide?
* Better night vision
* Fighting infections
* Healthy skin
27
What is the primary role of Vitamin D (Calciferol)?
Strengthens bones
28
What are the functions of the Vitamin B group?
Strong metabolism , energy production
29
What is the function of calcium in the body?
* Strong bones/teeth
* Healthy muscles
* Clotting blood
30
What can occur due to calcium deficiency?
Rickets, bending bones
31
What is one of the primary functions of Iron in the body?
Making haemoglobin
32
What condition is caused by Iron deficiency?
Iron deficiency anemia
33
What are the benefits of Fibre for the digestive system?
Helps maintain bowel health, lowers cholesterol, controls blood sugar, helps achieve a healthy weight
34
What does a balanced diet consist of?
The correct amount of each food group to suit your lifestyle
35
What energy needs are associated with more active lifestyles?
Need more energy per day
## Footnote
Increased activity demands higher caloric intake.
36
Who requires more energy based on body weight?
Heavier individuals typically require more energy.
37
What dietary needs do growing individuals have?
More energy per their body mass
38
What do pregnant women need more of to support the foetus?
More calcium for bone development
39
Why might menstruating women need more Iron?
Due to blood loss during menstruation
40
What is digestion?
The break down of large, insoluble molecules into smaller, soluble molecules.
41
What is the purpose of digestion?
To absorb small, soluble molecules into the blood.
42
What type of breakdown relies on chewing and stomach churning?
Mechanical/Physical Breakdown.
43
What aids chemical breakdown in digestion?
Digestive enzymes, which are biological catalysts.
44
How much faster does digestion occur with enzymes?
1,000,000,000 times faster.
45
What enzyme digests starch into maltose?
Amylase.
46
What is maltose further digested into, and using what enzyme?
Glucose, using maltase.
47
What enzyme digests proteins into amino acids?
Protease.
48
Where does protease digest proteins?
In the stomach and small intestine.
49
How are lipids emulsified?
By bile.
50
What products result from the digestion of lipids?
Fatty acids and glycerol.
51
What two processes are involved in digestion?
* Mechanical/Physical Breakdown
* Chemical Breakdown.
52
What is the role of bile in emulsification?
Bile breaks down fat into smaller fat droplets, increasing the surface area for lipase to digest.
53
What is emulsification?
A physical process where bile breaks down fat into smaller fat droplets.
54
What does bile do to stomach acid and why?
Bile neutralises acid from the stomach. This creates the optimum pH for enzymes to function.
55
What is peristalsis?
The process by which food passes through the gut via waves of muscle contraction.
56
How does fibre affect peristalsis?
Fibre provides more grip/friction, improving the effectiveness of peristalsis.
57
Where is bike made and stored?
Made in the liver, stored in the gall bladder
58
What are 6 steps of digestion
(PIG DIAGRAM)
59
What is absorption in the context of digestion?
Movement of the products of digestion (glucose, amino acids, glycerol & fatty acids) from the lumen of the small intestine into the blood or lymph nodes by diffusion or active transport.
60
What are the products of digestion that are absorbed?
* Glucose
* Amino acids
* Glycerol
* Fatty acids
61
What are the two mechanisms of transport for absorption?
* Active transport
* Diffusion
62
What adaptations increase the exchange surface for absorption?
* Large surface area (villi & microvilli)
* Length of approximately 10 meters
* Narrow structure to prevent food from getting stuck
* Extensive blood supply to maintain high concentration gradient
* Lacteals to remove fatty acids and glycerol
* Short diffusion distance (1 cell thick)
* Muscle action to push food along
63
What maintains a high concentration gradient in the small intestine?
Extensive blood supply
64
What are enzymes?
Proteins made of amino acids that act as biological catalysts
65
What is the role of enzymes in chemical reactions?
They lower the activation energy required, speeding up the reaction
66
What is activation energy?
The energy required for particles to collide and initiate a chemical reaction
67
Give an example of how enzymes speed up the reaction of starch.
Starch digestion takes two weeks without enzymes but only a few seconds with amylase
68
What is the unique feature of each enzyme?
Each enzyme has a unique shape with an active site
69
What is the active site?
A groove on the enzyme that fits the substrate like a lock and key
70
Why are enzymes specific?
Only one substrate fits the active site of an enzyme
71
What is formed when an enzyme binds to its substrate?
Enzyme/Substrate Complex
72
What does the enzyme do to the bond between the substrate molecules?
Weakens and breaks the bond
73
What happens to the enzyme after the reaction?
It remains unchanged and can be used again
74
How does temperature affect the rate of reaction for enzymes?
Initially increases the rate due to more collisions, but after reaching its optimum it decreases as the enzyme gets denatured.
75
What is the optimum temperature for enzyme activity?
The temperature at which the reaction is fastest
## Footnote
This can vary depending on the specific enzyme.
76
What is denaturation in the context of enzymes and how do they become denatured?
A permanent change in protein shape, with extreme temperatures and pH levels.
77
What factors affect enzyme activity?
Light intensity, Carbon Dioxide availability, pH level, temperature
78
How does light intensity affect the rate of photosynthesis?
As light intensity increases, so does the rate of photosynthesis until something else is limiting
79
What is the approximate level of Carbon Dioxide (CO2) in the atmosphere?
0.04%
80
At what CO2 level is it no longer the limiting factor?
approximately 1%
81
What is the optimum pH for enzymes in the stomach, mouth and intestines?
Varies, but typically around 1-2 in the stomach, 7 in the mouth, and 8 in the intestines
82
What can happen to enzymes under too alkaline or acidic conditions?
They can denature
83
What is the reagent used to test for starch?
Iodine
84
What color indicates a positive test for starch?
Black
85
What is the reagent used to test for glucose?
Benedict's solution
86
What color change indicates a positive test for glucose using Benedict's solution?
Orange --> red
87
What is the reagent used to test for protein?
Biuret
88
What color indicates a positive test for protein?
Purple
89
What is the method for testing lipids?
Emulsion test by mixing with ethanol and water
90
What color indicates a positive test for lipids?
Milky white
## Footnote
A milky white emulsion indicates the presence of lipids.
91
How do you test for starch?
Use a dimple dish and add iodine to food and mix
92
How do you test for glucose?
Use a test tube and add Benedict's to food then mix & heat
93
How do you test for protein?
Use a dimple dish and add Biuret and alkali to food and mix
94
How do you test for lipids?
Use a test tube, add ethanol, and then add water
95
Fill in the blank: A negative test for glucose shows a color change of _______.
Blue
## Footnote
Blue indicates the absence of reducing sugars.
96
Fill in the blank: A negative test for starch shows a color change of _______.
Brown
## Footnote
Brown indicates that starch is not present.
97
Fill in the blank: A negative test for lipids shows a color change of _______.
Clear
## Footnote
Clear indicates that no lipids are present.
98
What is the chemical equation for photosynthesis?
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
99
What role does chlorophyll play in plants?
Chlorophyll traps light energy, which is turned into chemical energy
## Footnote
Chlorophyll is located inside chloroplasts and is essential for photosynthesis.
100
How do plants utilise glucose?
* To make amino acids for growth and repair
* To make cellulose, which strengthens cell walls
* To make fats and oils, especially in seeds
* For respiration, where glucose is broken down to release energy
* Stored as starch for efficient storage because it is more compact and insoluble
## Footnote
Starch is preferred for storage because it is insoluble and more compact than glucose.
101
What is the significance of starch in plants?
Starch is insoluble and more compact than glucose, making it efficient for storage
## Footnote
This allows plants to store energy and break it down when needed, such as during winter.
102
What are the deficiency symptoms of nitrate in plants?
Stunted growth, older leaves turning yellow
## Footnote
Nitrate is essential for making amino acids, which are crucial for growth.
103
What deficiency symptoms occur due to a lack of magnesium?
Leaves turn yellow with dead spots
## Footnote
Magnesium is important for chlorophyll production.
104
What happens to young leaves when there is a phosphorus deficiency?
Young leaves turn purple
## Footnote
Phosphorus is vital for DNA production and energy transfer.
105
Fill in the blank: Plants obtain their _______ through photosynthesis.
food
## Footnote
This refers to the glucose produced during photosynthesis.
106
True or False: Glucose is more efficient for storage than starch in plants.
False
## Footnote
Starch is more efficient for storage because it is insoluble and compact.
107
What is the first step in testing leaves for starch?
Place the leaf in a beaker and fill it with boiling water to stop further reactions.
108
What does boiling water do to the leaf during the starch test?
It softens and kills the leaf.
109
What is used to dissolve the membrane of the leaf in the starch test?
Ethanal.
110
How long should the boiling tube with ethanol and leaf be placed in hot water?
5 minutes.
111
What happens to the leaf after being removed from ethanol?
It is rinsed to observe the color change.
112
What color change indicates the presence of starch in the leaf?
The leaf turns black when iodine is added.
113
What does a brown leaf indicate in the starch test?
Starch was not present and the leaf respired recently.
114
What does a black leaf indicate in the starch test?
Starch was present due to recent photosynthesis.
115
Name a factor that affects photosynthesis.
Light intensity.
116
What is the role of chlorophyll in the photosynthesis experiment?
Affects the leaf's ability to photosynthesize.
117
What type of leaf is used to test the effect of carbon dioxide on photosynthesis?
A leaf with KOH, which absorbs CO2.
118
Fill in the blank: The leaf in the dark was ______, showing that starch was not present.
brown
119
Fill in the blank: The leaf in the light turned ______, indicating starch was present.
black
120
What is the function of the waxy cuticle in plants?
Prevents water loss
## Footnote
The waxy cuticle is a protective layer that helps retain moisture in plants.
121
What are palisade cells primarily responsible for?
Contain many chloroplasts, site of photosynthesis
## Footnote
Palisade cells are located beneath the epidermis and are crucial for capturing sunlight.
122
What is the role of the spongy layer in leaves?
Contains many air spaces for gases to diffuse through
## Footnote
This layer aids in gas exchange within the leaf.
123
What do guard cells regulate?
Open and close stomata
## Footnote
Guard cells control the exchange of gases and water vapor in and out of the leaf.
124
What are the components of a vein in plant leaves?
Xylem and phloem
## Footnote
Xylem transports water and minerals, while phloem transports sugars.
125
Where are stomata primarily located in leaves?
Lower epidermis
## Footnote
Stomata are pores that facilitate gas exchange.
126
Fill in the blank: The _______ cuticle prevents water loss in plants.
waxy
127
True or False: The spongy layer has fewer air spaces than the palisade layer.
False
## Footnote
The spongy layer contains many air spaces compared to the palisade layer.
128
What is the primary function of the epidermis in leaves?
Protective layer with few chloroplasts
## Footnote
The epidermis acts as a barrier and helps protect internal tissues.
129
What is the main purpose of stomata in leaves?
Allows gases in and out of the leaf
## Footnote
Stomata are essential for photosynthesis and respiration.
130
131
What is the first step in investigating energy content of food?
Weigh the mass of food
## Footnote
This is essential for calculating the energy content per gram.
132
How much water is measured for the energy content experiment?
20ml of water
## Footnote
This volume is used to absorb heat during the burning process.
133
What is measured before burning the food?
The temperature of water
## Footnote
This initial temperature is needed to calculate the temperature change.
134
What is done to the food sample during the experiment?
Set fire to food and hold it under the test tube
## Footnote
This process allows the food to release energy through combustion.
135
What is measured after the food is completely burned?
The temperature of water again
## Footnote
This final temperature is used to calculate the change in temperature.
136
What formula is used to calculate the energy of food?
Energy = change in temp. x mass of water (g) x 4.2
## Footnote
The constant 4.2 represents the specific heat capacity of water.
137
What is the energy content formula when using a food sample?
Energy content = energy of food (1/9)
## Footnote
This formula helps determine energy per gram of the food.
138
What is the example temperature change for a crisp in the experiment?
25°
## Footnote
This is an example of how temperature change is recorded.
139
What is the energy content calculated for the given example?
935.41 J/g
## Footnote
This value indicates the energy released per gram of the food.
140
What equipment is used to hold the water during the experiment?
Test tube
## Footnote
This vessel is crucial for containing the water and measuring temperature changes.
141
What is the role of the thermometer in the experiment?
To measure the temperature of water
## Footnote
Essential for determining the heat absorbed by the water.
142
Which apparatus can increase accuracy in the experiment?
Stirrer
## Footnote
A stirrer helps maintain uniform temperature throughout the water.
143
What additional feature can improve the experiment's accuracy?
Insulation
## Footnote
Insulation minimizes heat loss to the surroundings.
144
What is used to handle the burning food safely?
Tongs
## Footnote
Tongs are necessary to prevent burns during the experiment.
145
What is the importance of a heat-proof mat in the experiment?
To protect the surface from heat damage
## Footnote
It ensures safety during the burning process.
146
147
What is the first step in the method of investigating the effect of temperature on enzymes?
Add a drop of iodine into the depressions on the dimple dish
148
How much starch solution is measured in the test tube?
3ml
149
How much amylase solution is measured in the test tube?
3ml
150
At which temperatures are the starch and enzyme solutions placed in a water bath?
5°C, 20°C, 40°C, 60°C, and 75°C
151
How long should the starch and enzyme solutions equilibrate to the temperature of the water bath?
5 minutes
152
What should be done immediately after mixing the starch and amylase solutions?
Start a timer and add a drop to the first depression
153
How often should a drop be added to the first depression after mixing?
Every 15-30 seconds
154
What is noted to determine when there is no longer any starch present?
The timer when there is no color anymore
155
What was the time taken for the reaction at 20°C?
240 seconds
156
What was the time taken for the reaction at 30°C?
180 seconds
157
What was the time taken for the reaction at 40°C?
120 seconds
158
What was the time taken for the reaction at 60°C?
210 seconds
159
What happens to the enzyme at 75°C?
It is denatured
160
Fill in the blank: The method involves measuring starch and amylase solutions in a _______ dish.
dimple
