biological molecules + Enzymes Flashcards
1
Q
What is the purpose of carbohydrates
A
To be used by the process of respiration to make energy for cells
2
Q
Which sugar is found in most processed sweet foods
A
Sucrose
3
Q
Name two Monosaccharides
A
Glucose
Fructose
4
Q
Name three polysaccharides
A
Starch
Glycogen
Cellulose
5
Q
What are starch, cellulose and glycogen made of
A
Chains of glucose
6
Q
Give three examples of disaccharides
A
Lactose
Maltose
Sucrose
7
Q
What is the main sugar transported through plant cells
A
Sucrose
8
Q
Where is most carbohydrate in our body found from
A
Starch
9
Q
What is the only form of carbohydrate that the human body can process
A
Glucose
10
Q
Why is starch considered a storage carbohydrate
A
Because it is insoluble
11
Q
What is the main form of storage for plants
A
Starch
12
Q
What is the main storage form for humans and animals
A
Glycogen
13
Q
Which tissues is glycogen found in
A
The liver and muscles
14
Q
Why can humans not digest cellulose
A
Because our gut does not contain the enzyme needed to break it down
15
Q
What do humans use cellulose for and why
A
For dietary fibre, because it provides the food in the gut with something to push against and so keeps the food moving
16
Q
What are three purposes of lipids
A
to provide the body with an energy store
To make cell membranes
To provide insulation
17
Q
What is the percentage mass of carbohydrates in the body
A
1%
18
Q
What three elements do lipids contain, and explain the oxygen concentration compared to a carbohydrate
A
hydrogen, carbon and oxygen(but this is less than a carbohydrate)
19
Q
What is the state of plant lipids at room temperature
A
Liquid
20
Q
Name the three elements present in carbohydrates
A
Oxygen, hydrogen, carbon
21
Q
What does insulation do
A
Reduces heat loss through the body
22
Q
What are most lipids made from
A
One glycerol molecule chemically bonded to three fatty acids
23
Q
What two types of lipids in excessive amounts can cause heart disease?
A
Saturated fats and cholesterol
24
Q
Name two foods and one place in the body wher cholestrerol can be found from
A
Meat, eggs and from the liver
25
Where are saturated fats found from and where are unsaturated fats found from
Saturated- animal based foods
| Unsaturated- plant based
26
What is a “fat” at room temperature
solid
27
Give six examples of lipids
Meat, butter, oil, milk, cheese, egg
28
What is the percentage mass of protein in the body
18%
29
What is protein made from
Chains of amino acids
30
How many types of amino acids are there
20 types
31
What is a peptide
A short chain of amino acids
32
How are different proteins formed
When there is a change in the order of amino acids
33
What determines the function of a protein
The shape of a protein, determined by the order of amino acids
34
Why is ethanol used in the lipids food test
Because fats and lipids are insoluble in water
35
What is the name of the test for glucose
Benedict’s test
36
What is the name for the test for protein
Biuret test
37
Describe the test for glucose
Place crushed food sample in a test tube and stir it with distilled water
add a few drops of Benedict’s solution
Place in a heated water bath for water to boil
should turn orange-red of glucose is present
38
Describe the test for protein
Add sample of protein in a test tube with distilled water and stir
Add biuret solution which is potassium hydroxide and copper sulphate
If protein is present should turn purple
39
Apart from glucose, what other types of reducing sugars can the Benedict’s test be used for?
Other monosaccharides and disaccharides
40
Which disaccharide can not be used for the Benedict’s test?
Sucrose
41
If you have a liquid, how would you perform the Benedict’s test
Add a few drops of Benedict’s solution
Heat in a water bath
Blue colour should turn orange/ brick red if glucose is present
42
Describe the test for starch
With a spatula, place food sample on a dish OR 1cm^3 liquid in test tube
Add a few drops of iodine solution
Should turn from yellow brownish colour to blue black
43
Describe the test for lipids
Add the food sample to a test tube and add a few drops of ethanol
Shake vigorously
Pour solution into test tube of water
If lipids are present then it should turn into a cloudy white emulsion
44
Describe the colpur at the start and end of the emulsion test
Colourless———-) cloudy white emulsion
45
Describe the colors at the start and end of the glucose test
Blue—-) orange
46
Give three possible reasons why we should not overheat our cells
- denature enzymes so wouldn’t be able to function properly
- could increase activity of non useful reactions
- would require a lot more energy
47
What is the difference between Induced fit model and lock and key model
- Induced fit model suggests active sight of enzyme changes slightly to fit substrate
- Lock and key model suggests the active sight is already perfect for substrate
48
Where is pepsin found
| And give two places where amalyse is found
Pepsin is found in the stomach
| Amylase is found in the pancreas and salivary glands
49
Explain how increased temperature causes enzymes to denature
Breaks the bonds of amino acids that holds the enzyme together
So active site changes
So is no longer complimentary to substrate
50
What “kind” of enzymes are present in the digestive system and what do they do
Extracellular enzymes, secreted onto food to break them down
51
Can an enzyme be used for more than one type of substrate
No
52
How does an enzyme substrate complex lower the activation energy of a reaction
Due to the presence of the enzyme
| As it catalyses the reaction
53
What are metabolic reactions
The chemical reactions that take place inside a cell
54
Where do enzymes exactly come from in the cell and where do they go? In terms of intercellular enzymes. Describe the list
Nucleus—-) Genes——) enzyme ——) cytoplasm
55
Definition of a catalyst
A chemical that speeds up a reaction without being used
56
Describe the steps of an enzyme reacting with a substrate(4)
Enzyme and substrate randomly moving in a solution, Due to random movement, they collide
Substrate is complimentary to active sight- so enzyme substrate complex forms-reaction happens
Product formed from the substrate and released
Enzyme is unchanged so catalyze another chemical reaction
57
What is the optimum temperature if the human body
37degrees
58
Why does increasing the temperature increase the activity of an enzyme
Because it gains more kinetic energy
so has more frequent collisions with the substrate,
making reaction faster
59
For an enzyme graph, why is the part after the optimum very steep even though it is denatured
Because it is still high temperature so a lot of kinetic energy and collisions
60
What might be a problem the enzyme and substrate encounter during collision
Substrate may be at the wring angle
61
What is the relationship between the organism and the optimum temperature of most of its enzymes
Optimum temperature is usually close to body temperature of organism
62
Name an enzyme in the human body which has a low optimum PH and why
Pepsin, because it is located in the stomach which has a lot of hydrochloric acid in it
63
What is the PH inside most cells
PH7(neutral)
64
Amalyse breaks ….. down into…..
Starch into Maltose
65
Describe the test for temperature on amylase activity
1) starch solution and amylase solution placed in water bath and heated to certain temperature
2) spotting tile prepared with iodine drops
3) . After fifteen minutes mix amylase into starch in one tube(digestion starts)
4) After every thirty seconds drop the solution into a dimple
5) record the time when the color changes to yellow
6) repeat with other temperatures of water baths
66
Why is the starch amylase solution still kept in a water bath when reaction is taking place?
To control the temperature and to make sure it doesn’t affect any variables
67
Why are the solutions at the beginning of the temperature amylase experiment kept same temperature
To control the enzyme activity as temperature can affect this
68
Which enzyme breaks up hydrogen peroxide and what are its products
Catalase
| Water and oxygen
69
Why are potato used in the PH catalyst experiment
Because their tissues are high in catalase
70
Describe the steps of the PH catalase experiment
Cut potatoes and place and crush in distilled water
Add to boiling tube and Add buffer solution
Add hydrogen peroxide and attach a bung and delivery tube to beaker of water
Count how many bubbles are present in one minute
Repeat for different Buffer PH solutions
71
One PH solution produces 39 bubbles
One PH solution produces 45 bubbles
Which solution makes the enzymes function the fastest
45 bubbles
| because more bubbles in a given time so more oxygen
72
Why is buffer solution used in an experiment to measure PH
Because it’s resists change to PH
73
Describe two problems with the amylase PH experiment
1) only taking recordings every thirty seconds, but reaction could take place in between
2) Changes in iodine color are difficult to see and are subjective
74
Describe the test for PH in amylase using iodine solution
1) place amylase solution, buffer solution and starch solution in a water bath, heat to optimum temperature temperature
2) pour starch solution into amylase buffer solution
3) place in water bath and start stop watch
4) Take droplet out every thirty seconds and record time taken for solution to remain yellow
75
In an “investiagting temperature on starch and amalyse experiment”
Why would you rock the solution backband forth
To mix the amalyse and starch together
76
If you carried out the investigation for the effect of temperature on amalyse with 40degrees rather than 20degrees, describe how the appearance if the spotting tray would be different(2)
There would be less blue tiles and more yellow tiles
| And less starch wouldve been digested
77
If you carried out the investigation for the effect of temperature on amalyse with 40degrees rather than 20degrees, Explain why there would be a difference in the appearance of the spotting tray (2)
Less spotting tiles that are blue
Because 40degrees would be closer to the optimum temperature,
So there would be more kinetic energy in the particles
So there would be more frequent collisions with the enzymw active site and the substratw
78
Can glucose be broken down by amalyse
No
79
Can glucose be absorbed in the stomach
No
80
List in order, the greatest biological molecule in our body to the smallest and their percentages(3)
Protein 18%
Lipids 10%
Carbohydrates 1%
81
What is the enzyme that breaks down maltose into glucose
Maltase
82
What is the purpose of firbre in the body
To provides roughage to food to provide the muscles of the gut with something to push against
83
Name two problems a deficiency of dietary fibre can lead to
Constipation
| Colitis
84
What is a deficiency formed form the deficiancy of carbohydrates
Ketosis
85
What is the function of vitamin d in the body
to help bones to grow
86
What is thr deficiency of vitamin d
Rickets, where the bones are deformed
87
What is the deficiency of vitamin a
Night blindess, being unbale to see in dim conditions
88
What is the deficiency of vitamin C called and explain, and thrn give an example
Scurvy, when the body is unable to make connective tiusse so is unable to heal wounds and thus causes bleeding, such as in the gums
89
What is the function of vitamin A
To produce light sensitive retine
90
Which vitamin do we get form sunlight
Vitamin d
91
If you carried out the investigation for the effect of temperature on amalyse with 40degrees rather than 20degrees, why would you need to keep the temperature in both test tubes the same
To keep the temperature constant
92
Can glucose be broken down by amalyse
No
93
What is the purpose of the protein molecule insulin and an anitobody, and where are each found
Insluin lowers blood glucose levels and is found in the pancreas
Antibody binds to antigens and is found in a white blood cell
94
Explain how the enzyme activity of amalyse decreases from 37-50 degrees
Enzyme becomes denatured
Because increased heat breaks the bonds of the enzyme
So the active site changes
AND THE SUBSTRATE CAN NO LONGER FIT
