Brainscape's Knowledge GenomeTM

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


See full index

AQA AS Biology > 3.1 Biological Molecules - Monomers and Polymers, Carbohydrates, Lipids, Proteins and Enzymes > Flashcards

3.1 Biological Molecules - Monomers and Polymers, Carbohydrates, Lipids, Proteins and Enzymes Flashcards

Monomers and Polymers, Carbohydrates, Lipids, Proteins and Enzymes

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

What are monomers?

A

The smaller units from which larger molecules are made from.

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

What are polymers?

A

Molecules made from a large number of monomers that join together.

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

Name three examples of monomers?

A

Monosaccarides, amino acids and nucleotides.

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

What is a condensation reaction?

A

Where two molecules join two molecules together with a formation of a chemical bond and an elimination of a water molecule.

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

What is a hydrolysis reaction?

A

Breaks a chemical bond between two molecules and involves the use of a water molecule.

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

What are monosaccarides?

A

They are monomers from which larger carbohydrates are made.

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

Name three examples of monosaccarides?

A

Glucose, fructose, and galactose.

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

What bond is formed between two monosaccarides during a condensation reaction?

A

A glycosidic bond.

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

What are disaccarides?

A

Formed by the condensation of two monosaccarides.

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

What is maltose?

A

A disaccaride formed by the condensation of two glucose molecules.

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

What is sucrose?

A

A disaccaride formed by the condensation of one glucose molecule and one fructose molecule.

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

What is lactose?

A

A disaccaride formed by the condensation of one glucose molecule and one galactose molecule.

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

What are isomers?

A

Molecules with the same chemical formula but have different structures.

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

What are the two glucose isomers?

A

α-glucose and β-glucose.

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

Where is the H in α-glucose?

A

At the top.

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

Where is the H in β-glucose?

A

At the bottom.

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

What are polysaccarides?

A

Polymers that are formed by the condensation of many glucose units.

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

Name three example of polysaccarides?

A

Cellulose, Starch, and Glycogen.

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

What is starch?

Where and how is it found?

What are the bonds?

A

A polysaccaride that is formed by the condensation of α-glucose.
Storage of glucose found only in plants as small grains.
1,4- and 1,6- glycosidic bonds.

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

How does the structure of starch differ?

A

Amylose is coiled/helical

Amylopectin is branched

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

What are the properties and functions of starch? (3)

A
  • LARGE & INSOLUBLE = so water potential is not affected and does not diffuse out of cells.
  • COILED/COMPACT = a lot of it can be stored in a small space.
  • BRANCHED =ends can be acted on by enzymes to be hydrolysed quickly into glucose.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is Glycogen?

Where and how is it found?

What are the bonds?

A

A polysaccaride formed by the condensation of α-glucose.
Storage of glucose in only animals as small granules in the liver and muscles.

1,4- and 1,6- glycosidic bonds.

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

What are the properties and function of glycogen?

A
  • INSOLUBLE = does not affect water potential and cannot diffuse out of cells
  • COMPACT = a lot of it can be stored in a small space
  • HIGHLY BRANCHED = ends can be acted on at the same time by enzymes so can be hydrolysed quickly.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is cellulose?

Where is it found?

A

A polysaccaride formed by the condensation of β-glucose.

Found only in plant cells to provide strength it

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

What are the properties and function of cellulose?

A
  • Straight unbranched chains that run parallel to one another, allowing hydrogen bonds which forms cross-linkages between adjacent cells.
  • Hydrogen bonds form micro-fibrils (fibres) to provide strength/rigidity to the cell wall.
  • PERMEABLE = large gaps remain between different micro-fibrils to allow selective absorption at the cell membrane.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What characteristics do lipids have? –> What atoms do they contain and are they soluble in water?

A

They contain C, H, O atoms where the proportion of these atoms is smaller than carbohydrates.

They are insoluble in water but soluble in organic solvents such as alcohol.

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

What are the 4 roles of lipids?

A
  • Source of energy = provide twice the energy of carbohydrates
  • Waterproofing
  • Insulation
  • Protection (stored around the organs e.g. kidneys)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the two groups of lipids?

A

Triglycerides and phospholipids

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

What are triglycerides?

What bond will it form?

A

Formed by the condensation of one molecule of glycerol and three molecules of fatty acid.
This will form 3 ester bonds with 3 water molecules.

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

How does a triglyceride’s structure relate to its function? (4 points)

A
  • HIGH RATIO of energy storing C-H bonds to C bonds so an excellent source of energy
  • LOW MASS to energy ratio so good storage molecules with a lot of it stored in a small volume.
  • LARGE AND NON POLAR so are insoluble and water potential is not affected.
  • HIGH RATIO OF H-O ATOMS so can release water whenever they are oxidised to provide source of water.
31
Q

What are phospholipids?

A

one of the fatty acids of a triglyceride is substituted by a phosphate-containing group.

32
Q

How does a phospholipid’s structure relate to its function? (3)

A
  • Polar molecules so in an aqueous environment meaning a bi-layer within the cell-surface.
  • Hydrophilic heads helps to hold at the surface of the cell surface membrane.
  • Form gylcolipids by combining with carbohydrates withing cell-surface membrane for cell recognition.
33
Q

Which part is hydrophilic and which part of hydrophobic?

A

Phosphate head is hydrophilic and phosphate tail is hydrophobic creating.

34
Q

Are micelles created by the phosphate head or tail?

What are they?

A

Enables lipid digestion products to be transported.

35
Q

What are saturated fatty acids?

What do they form?

A

Fatty acids where there are no double bonds between the C atoms.
Form solids, most common in animals.

36
Q

What are unsaturated fatty acids?

What do they form?

A

Fatty acids where there are one or more double bonds between the C atoms.
Form liquids, most common in plants.

37
Q

What are amino acids?

A

Monomers from which proteins are made.

38
Q

What 3 things does a general structure of an amino acid include?

A
  • Amine group = NH2/H2N
  • Carboxyl group = COOH
  • R = side chain.
39
Q

How many different types of amino acids are there?

A

20.

40
Q

How do amino acids differ?

A

They have a different R group.

41
Q

What are globular proteins?

A

soluble proteins where polypeptide has a 3D structure e.g. enzymes, hormones. (functional proteins)

42
Q

What are fibrous proteins?

A

insoluble and strong proteins where polypeptide is linear and are usually structural proteins. e.g. keratin, collagen.

43
Q

What bond does a condensation reaction between two amino acids form?

A

Peptide bond.

44
Q

What are dipeptides?

A

Formed by the condensation of two amino acids.

45
Q

What are polypeptides?

A

Formed by the condensation of many amino acids.

46
Q

What is the role of hydrogen bonds in the structure of proteins?

A

Protein stability.

47
Q

What is the role of ionic bonds in the structure of proteins?

A

bind basic proteins and potent electrostatic attractions.

48
Q

What is the role of disulfide bridges in the structure of proteins?

A

Protein shape and stability.

49
Q

Describe the primary structure of proteins:

A

= order and number of amino acids in the proteins.

  • initial sequence of a protein that determines the function at the end.
  • polypeptide chain held by peptide bonds.
50
Q

Describe the secondary structure of proteins and the bonds:

A
  • Polypeptide chains that form α-helix or β-pleated sheets.

- held together by weak hydrogen bonds (between carboxyl and amine group)

51
Q

Describe the tertiary structure of proteins:

A
  • secondary structure twists and folds again to create a 3D strucutre
52
Q

Describe the tertiary structure of proteins:

A
  • secondary structure twists and folds again to create a 3D structure
53
Q

Describe the hydrogen bonds in tertiary structure:

A

there are numerous bonds that are weak.

54
Q

Describe the ionic bonds in tertiary structure:

A
  • forms between the carboxyl and amine group

- strong but can be easily broken by changes in pH, weaker than disulfide bonds.

55
Q

Describe the disulfide bridges in tertiary structure:

A
  • interactions between the sulfur in the R group of the amino acid cysteine which are strong and not easily broken.
56
Q

Describe the quaternary structure of proteins:

A
  • large and complex molecules with multiple binding sites

- formed by 2 or more polypeptide chains.

57
Q

What are three examples of quaternary structure proteins and how many chains do they have?

A
  • Collagen has 3
  • Haemoglobin has 4
  • antibodies have 3
58
Q

What is the test for starch?

A

add few drops of iodine. Will turn from orange/brown to blue/black

59
Q

What is the test for reducing sugars?

A

heat with Benedict’s solution. Will turn orange/brick red.

60
Q

What is the test for non-reducing sugars?

A

Heat with Benedict’s solution.
Add HCL to hydrolyse gylcosidic bonds
Add sodium hydrogen carbonate to neutralise solution
Heat with benedicts which will turn brick red.

61
Q

What is the test for lipids?

A

Add ethanol and shake vigorously.
Add water and shake gently.
Will turn cloudy/milky emulsion if lipid is present.

62
Q

What is the test for proteins?

A

Add Biuret’s reagent to sample at room temp.

Colour change from blue to purple.

63
Q

What are enzymes?

A

Biological catalysts/proteins that speeds up the reaction by lowering the activation energy without changing itself.

64
Q

What makes enzymes specific?

A

they have specific active sites where only complementary substrates can bind, forming an enzyme-substrate complex.

65
Q

What is the lock and key model?

A

Where the active site is rigid, and only complementary substrates can bind.

66
Q

what is the induced-fit model?

A

The active site will change shape to enable the substrate to bind exactly to form an enzyme-substrate complex.
2 products will be formed and the enzyme will be unchanged.

67
Q

How does enzyme concentration affect enzyme-controlled reactions?

A
  • ↑ in enzyme concentration, ↑ rate of reaction as there will be more successful collisions and ES complex.
  • Rate of reaction will no longer increase after a certain point because substrates are used up so becomes a limiting factor.
68
Q

How does enzyme concentration affect enzyme-controlled reactions?

A
  • ↑ in enzyme concentration, ↑ rate of reaction as there will be more successful collisions and ES complex.
  • Rate of reaction will no longer increase after a certain point because substrates are used up so becomes a limiting factor.
69
Q

How does substrate concentration affect enzyme-controlled reactions?

A
  • ↑ in substrate concentration, ↑ rate of reaction as more successful collisions and ES complexes formed.
  • Rate of reaction will no longer increase as enzyme concentration becomes a limiting factor.
70
Q

How does pH affect enzyme-controlled reactions?

A
  • Each enzyme have different optimum pH. If away from the optimum, bonds in tertiary structure break so it will lose its active site shape, not forming ES complex.
71
Q

How does temperature effect enzyme-controlled reactions?

A
  • as temp↑, rate of reaction↑.
  • they have more kinetic energy which means molecules move faster, so more successful and frequent collisions. ↑ chance of forming ES complex.
  • After optimum temp, H and ionic bonds will break and will lose its active site shape so enzyme will become denatured.
72
Q

What is the effect on competitive inhibitors?

A
  • ↑ competitive inhibitors, rate of reaction ↓.
  • they have similar shapes to the substrates therefore will bind to the active site and block the substrates from binding, preventing ES complexes from forming.
73
Q

How does the concentration of non-competitive inhibitors affect the rate of reaction?

A
  • ↑ non-competitive inhibitors, rate of reaction ↓.
  • These will bind to the allosteric site which will alter the active site
  • less ES complex formed.

AQA AS Biology (4 decks)

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