biological molecules + Enzymes Flashcards

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1
Q

What is the purpose of carbohydrates

A

To be used by the process of respiration to make energy for cells

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2
Q

Which sugar is found in most processed sweet foods

A

Sucrose

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3
Q

Name two Monosaccharides

A

Glucose

Fructose

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4
Q

Name three polysaccharides

A

Starch
Glycogen
Cellulose

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5
Q

What are starch, cellulose and glycogen made of

A

Chains of glucose

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6
Q

Give three examples of disaccharides

A

Lactose
Maltose
Sucrose

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7
Q

What is the main sugar transported through plant cells

A

Sucrose

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8
Q

Where is most carbohydrate in our body found from

A

Starch

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9
Q

What is the only form of carbohydrate that the human body can process

A

Glucose

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10
Q

Why is starch considered a storage carbohydrate

A

Because it is insoluble

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11
Q

What is the main form of storage for plants

A

Starch

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12
Q

What is the main storage form for humans and animals

A

Glycogen

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13
Q

Which tissues is glycogen found in

A

The liver and muscles

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14
Q

Why can humans not digest cellulose

A

Because our gut does not contain the enzyme needed to break it down

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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

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16
Q

What are three purposes of lipids

A

to provide the body with an energy store
To make cell membranes
To provide insulation

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17
Q

What is the percentage mass of carbohydrates in the body

A

1%

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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)

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19
Q

What is the state of plant lipids at room temperature

A

Liquid

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20
Q

Name the three elements present in carbohydrates

A

Oxygen, hydrogen, carbon

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21
Q

What does insulation do

A

Reduces heat loss through the body

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22
Q

What are most lipids made from

A

One glycerol molecule chemically bonded to three fatty acids

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23
Q

What two types of lipids in excessive amounts can cause heart disease?

A

Saturated fats and cholesterol

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24
Q

Name two foods and one place in the body wher cholestrerol can be found from

A

Meat, eggs and from the liver

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25
Q

Where are saturated fats found from and where are unsaturated fats found from

A

Saturated- animal based foods

Unsaturated- plant based

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26
Q

What is a “fat” at room temperature

A

solid

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27
Q

Give six examples of lipids

A

Meat, butter, oil, milk, cheese, egg

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28
Q

What is the percentage mass of protein in the body

A

18%

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29
Q

What is protein made from

A

Chains of amino acids

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30
Q

How many types of amino acids are there

A

20 types

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31
Q

What is a peptide

A

A short chain of amino acids

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32
Q

How are different proteins formed

A

When there is a change in the order of amino acids

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33
Q

What determines the function of a protein

A

The shape of a protein, determined by the order of amino acids

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34
Q

Why is ethanol used in the lipids food test

A

Because fats and lipids are insoluble in water

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35
Q

What is the name of the test for glucose

A

Benedict’s test

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36
Q

What is the name for the test for protein

A

Biuret test

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37
Q

Describe the test for glucose

A

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

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38
Q

Describe the test for protein

A

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
Q

Apart from glucose, what other types of reducing sugars can the Benedict’s test be used for?

A

Other monosaccharides and disaccharides

40
Q

Which disaccharide can not be used for the Benedict’s test?

A

Sucrose

41
Q

If you have a liquid, how would you perform the Benedict’s test

A

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
Q

Describe the test for starch

A

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
Q

Describe the test for lipids

A

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
Q

Describe the colpur at the start and end of the emulsion test

A

Colourless———-) cloudy white emulsion

45
Q

Describe the colors at the start and end of the glucose test

A

Blue—-) orange

46
Q

Give three possible reasons why we should not overheat our cells

A
  • denature enzymes so wouldn’t be able to function properly
  • could increase activity of non useful reactions
  • would require a lot more energy
47
Q

What is the difference between Induced fit model and lock and key model

A
  • 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
Q

Where is pepsin found

And give two places where amalyse is found

A

Pepsin is found in the stomach

Amylase is found in the pancreas and salivary glands

49
Q

Explain how increased temperature causes enzymes to denature

A

Breaks the bonds of amino acids that holds the enzyme together
So active site changes
So is no longer complimentary to substrate

50
Q

What “kind” of enzymes are present in the digestive system and what do they do

A

Extracellular enzymes, secreted onto food to break them down

51
Q

Can an enzyme be used for more than one type of substrate

A

No

52
Q

How does an enzyme substrate complex lower the activation energy of a reaction

A

Due to the presence of the enzyme

As it catalyses the reaction

53
Q

What are metabolic reactions

A

The chemical reactions that take place inside a cell

54
Q

Where do enzymes exactly come from in the cell and where do they go? In terms of intercellular enzymes. Describe the list

A

Nucleus—-) Genes——) enzyme ——) cytoplasm

55
Q

Definition of a catalyst

A

A chemical that speeds up a reaction without being used

56
Q

Describe the steps of an enzyme reacting with a substrate(4)

A

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
Q

What is the optimum temperature if the human body

A

37degrees

58
Q

Why does increasing the temperature increase the activity of an enzyme

A

Because it gains more kinetic energy
so has more frequent collisions with the substrate,
making reaction faster

59
Q

For an enzyme graph, why is the part after the optimum very steep even though it is denatured

A

Because it is still high temperature so a lot of kinetic energy and collisions

60
Q

What might be a problem the enzyme and substrate encounter during collision

A

Substrate may be at the wring angle

61
Q

What is the relationship between the organism and the optimum temperature of most of its enzymes

A

Optimum temperature is usually close to body temperature of organism

62
Q

Name an enzyme in the human body which has a low optimum PH and why

A

Pepsin, because it is located in the stomach which has a lot of hydrochloric acid in it

63
Q

What is the PH inside most cells

A

PH7(neutral)

64
Q

Amalyse breaks ….. down into…..

A

Starch into Maltose

65
Q

Describe the test for temperature on amylase activity

A

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
Q

Why is the starch amylase solution still kept in a water bath when reaction is taking place?

A

To control the temperature and to make sure it doesn’t affect any variables

67
Q

Why are the solutions at the beginning of the temperature amylase experiment kept same temperature

A

To control the enzyme activity as temperature can affect this

68
Q

Which enzyme breaks up hydrogen peroxide and what are its products

A

Catalase

Water and oxygen

69
Q

Why are potato used in the PH catalyst experiment

A

Because their tissues are high in catalase

70
Q

Describe the steps of the PH catalase experiment

A

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
Q

One PH solution produces 39 bubbles
One PH solution produces 45 bubbles
Which solution makes the enzymes function the fastest

A

45 bubbles

because more bubbles in a given time so more oxygen

72
Q

Why is buffer solution used in an experiment to measure PH

A

Because it’s resists change to PH

73
Q

Describe two problems with the amylase PH experiment

A

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
Q

Describe the test for PH in amylase using iodine solution

A

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
Q

In an “investiagting temperature on starch and amalyse experiment”
Why would you rock the solution backband forth

A

To mix the amalyse and starch together

76
Q

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)

A

There would be less blue tiles and more yellow tiles

And less starch wouldve been digested

77
Q

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)

A

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
Q

Can glucose be broken down by amalyse

A

No

79
Q

Can glucose be absorbed in the stomach

A

No

80
Q

List in order, the greatest biological molecule in our body to the smallest and their percentages(3)

A

Protein 18%
Lipids 10%
Carbohydrates 1%

81
Q

What is the enzyme that breaks down maltose into glucose

A

Maltase

82
Q

What is the purpose of firbre in the body

A

To provides roughage to food to provide the muscles of the gut with something to push against

83
Q

Name two problems a deficiency of dietary fibre can lead to

A

Constipation

Colitis

84
Q

What is a deficiency formed form the deficiancy of carbohydrates

A

Ketosis

85
Q

What is the function of vitamin d in the body

A

to help bones to grow

86
Q

What is thr deficiency of vitamin d

A

Rickets, where the bones are deformed

87
Q

What is the deficiency of vitamin a

A

Night blindess, being unbale to see in dim conditions

88
Q

What is the deficiency of vitamin C called and explain, and thrn give an example

A

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
Q

What is the function of vitamin A

A

To produce light sensitive retine

90
Q

Which vitamin do we get form sunlight

A

Vitamin d

91
Q

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

A

To keep the temperature constant

92
Q

Can glucose be broken down by amalyse

A

No

93
Q

What is the purpose of the protein molecule insulin and an anitobody, and where are each found

A

Insluin lowers blood glucose levels and is found in the pancreas
Antibody binds to antigens and is found in a white blood cell

94
Q

Explain how the enzyme activity of amalyse decreases from 37-50 degrees

A

Enzyme becomes denatured
Because increased heat breaks the bonds of the enzyme
So the active site changes
AND THE SUBSTRATE CAN NO LONGER FIT