Brainscape's Knowledge GenomeTM

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


See full index

Biology > 1 Biological Molecules: 1 Biological Molecules > Flashcards

1 Biological Molecules: 1 Biological Molecules Flashcards

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.

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 joined together.

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

What are the key examples of monomers?

A

Monosaccharides, 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

A reaction that joins two molecules together with the formation of a chemical bond and involves the 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

A reaction that 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 monosaccharides?

A

The monomers from which larger carbohydrates are made.

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

What are the key examples of monosaccharides?

A

Glucose, fructose and galactose.

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

What does a condensation reaction between two monosaccharides form?

A

A glycosidic bond.

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

How are disaccharides formed?

A

By the condensation of two monosaccharides.

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

Glucose + glucose -> ?

A

Maltose.

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

Glucose + fructose -> ?

A

Sucrose.

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

Glucose + galactose -> ?

A

Lactose.

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

What are glucose’s isomers?

A

Alpha glucose and beta glucose.

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

Draw alpha glucose.

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

Draw beta glucose.

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

How are polysaccharides formed?

A

By the condensation of many glucose units.

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

How are glycogen and starch formed?

A

By the condensation of alpha glucose.

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

How is cellulose formed?

A

By the condensation of beta glucose.

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

What is the biochemical test for reducing sugars?

A

Benedict’s test:
1. Add Benedict’s reagent to a sample and heat it in a boiling water bath.
2. If positive, an orange-brown precipitate will form.

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

What is the biochemical test for non-reducing sugars?

A
  1. Do the Benedict’s test with the sample. If there is no colour change in the solution, the sugar is non-reducing.
    - 1. Add Benedict’s reagent to the sample and heat it
  2. Add acid to a new sample and boil it (to hydrolyse the sugar).
  3. Add an alkali to neutralise the solution.
  4. Retest the solution with Benedict’s reagent.
  5. If the solution forms an orange-brown precipitate, the sugar was non-reducing.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the biochemical test for starch?

A
  1. Add a few drops of iodine to the sample and mix.
  2. If starch is present, the solution will turn blue-black.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
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
23
Q

How are triglycerides formed?

A

By the condensation of one molecule of glycerol and three molecules of fatty acid, forming ester bonds.

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

How do phospholipids differ to triglycerides?

A

One of the fatty acids of a triglyceride is substituted by a phosphate group.

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

What are the properties and functions of triglycerides related to their structure?

A

Long hydrocarbon tails - contains lots of chemical energy which is released when broken down
Insoluble - don’t affect water potential

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

What are the properties and functions of phospholipids related to their structure?

A

Hydrophilic head and hydrophobic tails
- forms a bilayer with their heads facing out
- acts a barrier against water-soluble substances.

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

What is the test for lipids?

A

Emulsion test:

  1. Add ethanol to the sample and shake.
  2. Pour the solution in water.
  3. If lipids present, a milky emulsion will form.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does a saturated fatty acid mean?

A

No C=C double bonds.

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

What are monounsaturated fatty acids?

A

One C=C double bond.

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

What are polyunsaturated fatty acids?

A

More than one C=C double bond.

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

What are amino acids?

A

The monomers from which proteins are made.

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

What is the general structure of an amino acid?

A

NH2CRHCOOH

33
Q

What is the amine group?

A

NH2.

34
Q

What is a carboxyl group?

A

C=O

35
Q

What is a side chain represented as?

A

R

36
Q

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

A

A peptide bond.

37
Q

How are dipeptides formed?

A

By the condensation of two amino acids.

38
Q

How are polypeptides formed?

A

By the condensation of many amino acids.

39
Q

What may a functional protein contain?

A

One or more polypeptides.

40
Q

What is the primary structure of protein?

A

The sequence of amino acids in a polypeptide chain
(determined by the DNA sequence).

41
Q

What is the secondary structure of proteins?

A

Hydrogen bonds form between the amino acids in the chain.
This makes it coil into an alpha helix or fold into a beta-pleated sheet.

42
Q

What is the tertiary structure of proteins?

A

The secondary structure is coiled and folded further.
Hydrogen bonds, ionic bonds, and disulfide bridges form between different parts of the polypeptide chain.

43
Q

What does the 3D shape of a protein do?

A

It makes the protein distinctive and recognisable.

44
Q

What is the role of disulfide bridges in proteins?

A

In the tertiary structure.
Strong and not easily broken.
Forms between R-groups containing sulfur.

45
Q

What is the role of ionic bonds in proteins?

A

In the tertiary structure.
(Weaker than disulfide bridges and are easily broken by changes in pH).
(Forms between carboxyl and amino groups).

46
Q

What is the role of hydrogen bonds in proteins?

A

In the tertiary structure.
Numerous but easily broken.

47
Q

What is the quaternary structure of proteins?

A

Made of several different polypeptide chains held together by bonds.

48
Q

What is the test for proteins?

A
  1. Add sodium hydroxide solution
  2. Add copper (II) sulfate solution and mix.
  3. If proteins are present, the solution will turn purple.
49
Q

What is the structure of starch?

A

A mixture of 2 polysaccharides of alpha glucose.
Amylose and amylopectin.

50
Q

What is the structure of amylose in starch?

A

A long, unbranched chain of alpha glucose that is wound into a tight coil that makes it compact.

51
Q

What is the structure of amylopectin in starch?

A

A long, branched chain of alpha glucose.

52
Q

What are the functions of starch related to its structure?

A

Amylose - the coil is compact, so a lot of it can be stored in small spaces.
Amylopectin - its side branches allow enzymes to hydrolyse them simultaneously and rapidly so glucose monomers can be released very quickly.
Insoluble - doesn’t affect water potential

53
Q

What is the structure of glycogen?

A

Similar to amylopectin in starch but has more side branches and shorter chains

54
Q

What are the functions of glycogen related to its structure?

A

More branches means that stored glucose can be released more quickly which is important in respiration in animals.
Insoluble - doesn’t affect water potential
Compact - a lot of it can be stored in small spaces.

55
Q

What is the structure of cellulose?

A

Made of long, unbranched chains of beta glucose.
Every other beta-glucose monomer is flipped in the chain.
Allows hydrogen bonds to form cross linkages between adjacent chains to form microfibrils.

56
Q

What are the functions of cellulose related to its structure?

A

Long unbranched chains of beta-glucose are linked together by H bonds, forming strong microfibrils that provides structural support.

57
Q

Draw a peptide bond.

A

C(=O)N(H)

58
Q

What is protein’s function in enzymes?

A

Enzymes are roughly spherical in shape due to the tight folding of the polypeptide chains.
They’re soluble and often have roles in metabolism.

59
Q

What is protein’s role in antibodies?

A

They’re involved in the immune response.
Made up of 2 short polypeptide chains and 2 long polypeptide chains bonded together.

60
Q

What is protein’s role in transport proteins?

A

Channel proteins contain hydrophobic and hydrophilic amino acids which cause the protein to fold up and form a channel.
These proteins transports molecules and ions across membranes.

61
Q

What is protein’s role in structural proteins?

A

They’re physically strong.
Consists of long polypeptide chains parallel to each other with cross-links between them.
(Structural proteins include keratin and collagen.)

62
Q

How do enzymes work as catalysts?

A

They lower the activation energy of the reaction.

63
Q

What is the induced fit model of enzyme action?

A

The active site forms as the enzyme and substrate interact.
The proximity of the substrate leads to a change in the enzyme that forms the functional active site.
As the enzyme changes its shape, it puts a strain on the substrate molecule which distorts particular bonds in the substrate which lowers the activation energy needed.

64
Q

What is the effect of temperature on enzyme action?

A

Increasing temperature increases enzyme action because molecules have more KE so there are more frequent successful collisions.
If the temperature rises above a certain degree, it may cause hydrogen bonds and other bonds to break which causes a change in the shape of the enzyme, including the active site.
At first, the substrate fits less easily and rate slows.
The enzyme will then denature because it becomes so disrupted it stops working.
Optimum temperature differs from enzyme to enzyme.

65
Q

What is the effect of pH on enzyme action?

A

A change in pH may cause ionic and hydrogen bonds (that maintain the enzyme’s tertiary structure) to break, causing the active site to change shape so enzyme-substrate complexes can’t form anymore.
pH fluctuations inside organisms are usually small so they are more likely to reduce an enzyme’s activity than denature it.

66
Q

What is the effect of enzyme concentration on rate of reaction?

A

Increasing the enzyme concentration increases the rate of reaction.
The more enzyme molecules there are in a solution, the more likely a substrate molecule is to collide with one and form an enzyme-substrate complex.
If the amount of substrate is limiting, adding more enzyme has no effect since the available substrate is already being used as rapidly as it can be.

67
Q

What is the effect of substrate concentration on rate of reaction?

A

The higher the substrate concentration, the faster the rate of reaction.
More substrate molecules means collisions between substrate and enzyme are more likely, and so more active sites will be used.
After the saturation point, the addition of more substrate will have no effect on the rate of reaction since all the active sites are full.
Substrate concentration decreases with time during a reaction so the rate of reaction will also decrease (unless more substrate is added).

68
Q

What are the conditions for reactions to occur?

A

The reactants must collide with sufficient energy to alter the arrangement of their atoms to form the products.
The free energy of the products must be less that that of the reactants.

69
Q

What is the active site?

A

A specific region of the protein that is functional.

70
Q

What are enzymes?

A

Globular proteins that act as catalysts.

71
Q

What is the active site made of?

A

A small number of amino acids forming a small depression.

72
Q

How is the substrate held within the active site?

A

Temporary bonds form between certain amino acids of the active site and groups on the substrate molecule.

73
Q

What are the condition for an enzyme to work?

A

It must come into physical contact with the substrate and have a complementary active site and substrate.

74
Q

Why has our body temperature evolved to be 37 degrees instead of 40 degrees?

A

Despite many enzymes having an optimum temperature of 40 degrees,
- a higher temperature may increase metabolic rate which would be offset by the energy needed to maintain that temperature
- other proteins that are not enzymes could be denatured by higher temperatures.
- further rises in temperature (e.g. a fever) could denature enzymes.

75
Q

What is the formula for pH?

A

pH = -log10 [H+]

76
Q

How does the concentration of competitive inhibitors affect the rate of enzyme-controlled reactions?

A

Competitive inhibitor molecules have a similar shape to that of the substrate molecules so they compete with the substrate molecules to bind to the active site.
Increasing the concentration of substrate will decrease the effect of the inhibitor and so will increase the rate of reaction.

77
Q

What do non-competitive inhibitors do? What effect does increasing the concentration of substrate have on the effect of the inhibitor (and therefore the rate of reaction)?

A

Non-competitive inhibitors bind to another binding site other than the active site.
This causes the active site to change shape so the substrate molecules can no longer bind to it.
Increasing the concentration of substrate won’t make any difference to the effect of the inhibitor and so the reaction rate won’t change.

78
Q

What are the properties of an enzyme related to?

A

The tertiary structure of its active site and its ability to combine with complementary substrates to form an enzyme-substrate complex.

Biology (21 decks)

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