Brainscape's Knowledge GenomeTM

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


See full index

AS Biology - Unit 1 > Unit 3.1.2 - The Digestive System > Flashcards

Unit 3.1.2 - The Digestive System Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Digestion is the process where?

A

Large molecules care hydrolysed by enzymes to produce smaller molecules that can be absorbed and assimilated

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

What does absorption mean?

A

It is when molecules move from the digestive system into the blood

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

What does assimilated mean?

A

Where absorbed molecules are incorporated into body tissues

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

What are the two types of digestion?

A

Chemical and physical

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

What is meant by physical digestion?

A

It is when food is broken down into smaller pieces by the teeth in the mouth or by the churning movements of the stomach muscles

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

What is meant by chemical digestion?

A

Where polymers are broken down into monomers by hydrolysis

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

What are the monomers for carbohydrates called?

A

Monosaccharide

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

What are the monomers for protein called?

A

Amino acid

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

What is the difference between monosaccharaides and amino acids in terms of the elements they contain?

A

Monosaccharaides contain carbon, hydrogen and oxygen and amino acids contain the same elements as well as nitrogen

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

What is a polymer?

A

A large molecule made up of repeating smaller molecules called monomers

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

What reaction do you do to join polymers?

A

Condensation reaction

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

What reaction do you do to break up polymers?

A

Hydrolysis reaction

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

Out of a condensation reaction and hydrolysis reaction which ones requires water molecules and which one released water molecules?

A

Condensation reaction releases a water molecules and a hydrolysis reaction takes in a water molecule

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

Draw what happens during a hydrolysis reaction between polymers?

A

See flash card 2

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

Draw and label the parts of the digestive system?

A

See flash card 1

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

Starch is broken down into? by which enzyme?

A

Maltose by amylase

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

Maltose is broken down into? by which enzyme?

A

Glucose by maltase

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

Lipids are broken down into? by which enzyme?

A

Fatty acids + glycerol by lipase

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

Proteins are broken down into? by which enzymes?

A

Polypeptides by endopeptidase

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

Polypeptides are broken down into? by which enzymes?

A

Amino acids by exopeptidase

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

Name two examples of endopeptidase?

A

Pepsin and trypsin

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

Name an example of exopeptidase?

A

Peptidase

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

How is starch converted into glucose?

A

It is hydrolysed into maltose by the enzyme amylase, the maltose is then hydrolysed into glucose by the enzyme maltase

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

What is amylase released by?

A

The salivary glands and the pancreas

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

What is maltase released by?

A

The intestinal epithelium

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

What is lipase released by?

A

The pancreas and intestinal epithelium

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

Endopeptidase and exopeptidase are both examples of ?

A

Proteases

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

How is the salivary gland important in digestion?

A

It produces saliva which contains the enzyme amylase, saliva also lubricates the food making it easier to swallow

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

Where is bile produced, stored and released into?

A

Bile is made by the liver, stored in the gall bladder and then secreted into the small intestine

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

Give two reasons why bile is important in the digestive system?

A

It neutralises stomach acid so the enzymes in the small intestine aren’t denatured by the acidic pH value, it also emulsifies the lipids increasing the surface area of the lipase enzyme to work on

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

Name three functions for proteins within all living organisms? (not along the lines of growth and repair)

A

Antibodies, hormones and enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What bonds join the amino acids to make proteins?

A

Peptide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Draw the general structure of an amino acid?

A

See flash card 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the difference between amino acids in terms of structure?

A

They all have a different variable group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What reaction would join two amino acids together?

A

A condensation reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What reaction can break apart polypeptide chains and what molecule is released during this reaction?

A

Hydrolysis - water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Draw a hydrolysis reaction that will break apart a dipeptide?

A

See flash card 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Draw a condensation reaction that will join two amino acids to make a dipeptide?

A

See flash card 5

39
Q

Two amino acids joined together are called a?

A

Dipeptide

40
Q

What are the three levels within protein structure called?

A

Primary, secondary, tertiary and quaternary

41
Q

What is the primary structure of a protein?

A

A sequence of amino acids joined together by peptide bonds

42
Q

What is the secondary structure of a protein?

A

When the polypeptide chains begin to become folded to form beta pleated sheets and alpha helixes, hydrogen bonds hold their shapes

43
Q

What is the tertiary structure of a protein?

A

Pleated sheets and helixes fold over each other even more and other ionic, disulphide and hydrogen bonds form holding this shape

44
Q

What is a quaternary structure of a protein?

A

More than one polypeptide chain/tertiary structure protein together

45
Q

What test can you do for proteins?

A

The biuret test for proteins

46
Q

Describe what you do during a biuret test for proteins and the results you could get?

A

1.) add a few drops of sodium hydroxide to the solution
2.) then add copper sulphate to the solution
If a protein is present the solution will turn purple, if there are no proteins the solution will remain blue

47
Q

After the biuret test for protein the solution is blue, are proteins present?

A

No

48
Q

After the biuret test for protein the solution is purple, are proteins present?

A

Yes

49
Q

What is an enzyme?

A

A biological catalyst that speeds up the rate of reaction without being used up or changed

50
Q

How do enzymes speed up the rate of reaction?

A

They offer an alternative route for the reaction to take place with a lower activation energy

51
Q

When an enzyme binds to the active site what is formed?

A

Enzyme - substrate complex

52
Q

How do enzyme - substrate complexes lower the activation energy is two substrate molecules need to be joined?

A

It means the substrates are held close together so that the molecules can form bonds more easily

53
Q

How do enzyme - substrate complexes lower the activation energy is a substrate molecules need to separated apart?

A

The enzyme substrate complex means there is a strain on the bonds within the substrate, so the substrate can break apart more easily

54
Q

What are the two models that show how enzymes work called?

A

The lock and key model and the induced fit model

55
Q

What does the lock and key model show about enzymes and their substrates?

A

The enzymes active site is complementary in shape to the substrate so they can bind to form enzyme substrate complexes

56
Q

What does the induced fit model show about enzymes and their substrates?

A

The enzymes active site is similar in shape to the substrate, this means when the substrate binds to the active site the active site changes shape slightly so that the substrate fits perfectly

57
Q

Why can enzymes only catalyse one reaction?

A

Because only one substrate will fit into the enzymes active site

58
Q

What is the shape of an enzymes active site determined by?

A

The enzymes tertiary shape

59
Q

What three things effect the rate of reaction of an enzyme?

A

Temperature, pH and substrate concentration

60
Q

Why does increasing the temperature increase the rate of reaction of an enzymes up to a point?

A

The substrate molecules have more kinetic energy and are more likely to collide with the enzymes active site, each collision also happens with more energy so each collision is more likely to result in a reaction.

61
Q

What happens to the rate of reaction of an enzyme if you increase the temperature too much - past its optimum temperature?

A

The rate of reaction begins to rapidly decrease this is because the enzyme molecules vibrate too much and the bonds holding the enzyme together break and so the tertiary structure of the enzyme and its active site change, this means it can no longer form enzyme substrate complexes and is denatured

62
Q

What happens to the rate of reaction of an enzymes if the pH is too high or too low?

A

The H+ and OH- ions disrupt the bonds holding the enzymes together, so the tertiary structure and the active sites change, this means it can no longer form enzyme substrate complexes and is denatured

63
Q

Why does increasing the substrate concentration increase the rate of reaction up to a point?

A

If there are more substrate this means that enzyme substrate complexes will be more likely and so increasing the rate of reaction

64
Q

What happens to the rate of reaction of an enzymes if you continue to increase the substrate concentration and why?

A

The graph will level off, this is because all the active sites will be occupied and so no more enzyme substrate complexes can form and so the rate of reaction of the enzymes level off

65
Q

What is the point called when all the active sites are occupied?

A

Saturation point

66
Q

What two things can prevent enzyme activity?

A

Competitive inhibitors and non-competitive inhibitors

67
Q

How do competitive inhibitors work?

A

They are a similar shape to the substrate molecules and so they can bind to the active sites and block it so no substrate molecules can fit

68
Q

How do non-competitive inhibitors work?

A

They bind to the enzyme away from the active site, and they cause the active site to change shape

69
Q

Draw the structure of alpha glucose?

A

See flash card 6

70
Q

What bonds are formed between two monosaccharaides?

A

Glycosidic

71
Q

What is the difference between a polysaccharide and a disaccharide?

A

A disaccharide is two monosaccharaides and a polysaccharide is more than two

72
Q

Draw the condensation reaction between two alpha glucoses?

A

See flash card 7

73
Q

What reaction can join two monosaccharaides together?

A

Condensation reaction

74
Q

What reaction can break a disaccharide into two monosaccharaides?

A

Hydrolysis reaction

75
Q

Name three disaccharides?

A

Maltose, sucrose and lactose

76
Q

What two monosaccharaides are in maltose?

A

Glucose and glucose

77
Q

What two monosaccharaides are in sucrose?

A

Glucose and fructose

78
Q

What two monosaccharaides are in lactose?

A

Glucose and galactose

79
Q

What enzyme can break maltose down into glucose and glucose?

A

Maltase

80
Q

What enzymes can break sucrose down into glucose and fructose?

A

Sucrase

81
Q

What enzyme can break lactose down into glucose and galactose?

A

Lactase

82
Q

What is lactose intolerance caused by?

A

When you don’t have enough of the enzyme lactase to break down the lactose in diary properly

83
Q

What are the symptoms of lactose intolerance?

A

Stomach cramps, excessive flatulence and diarrhoea

84
Q

How can lactose intolerance cause stomach cramps and excessive flatulence?

A

The undigested lactose is fermented by bacteria and produces a gas which causes the stomach cramps and excessive flatulence

85
Q

How can lactose intolerance cause diarrhoea?

A

Because the lactose isn’t being broken down you will have a high concentration of lactose in the intestines, this lowers the water potential this means water moves in by osmosis increasing the water content in your faeces making them runny

86
Q

What can two categories can sugars be classified into?

A

Reducing and non reducing sugars

87
Q

What test can you do for the presence of reducing or non reducing sugars?

A

Benedict’s test

88
Q

Describe the benedict’s test for a reducing sugar and the results you would expect?

A

Heat with benedict’s reagent, if the sample turns brick red then a reducing sugar is present, if there are no reducing sugars the solution will remain blue

89
Q

Describe how you use benedict’s test to test for a non reducing sugar?

A

After doing the first test and finding no reducing sugars present, you boil a new sample with dilute hydrochloric acid and then neutralise with sodium hyrogencarbonate
Then you boil it again with the benedict’s reagent, if the sample turns brick red then a non reducing sugar is present, if there are no non reducing sugars the solution will remain blue

90
Q

When testing for a non reducing sugar why do you boil the sample with hydrochloric acid first?

A

To break any disaccharides into monosaccharaides

91
Q

What is an example of a non reducing a reducing sugar?

A

Non reducing - sucrose

Reducing - lactose and maltose

92
Q

What two polysaccharides is starch a mixture of?

A

Amylose and amylopectin

93
Q

What test can you do for the presence of starch?

A

Add iodine solution to the test sample, if starch is present the solution will go a dark blue black colour, if no starch is present the solution will remain a browny-orange colour

AS Biology - Unit 1 (6 decks)

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