Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology A Level > 1 - Biological Molecules > Flashcards

1 - Biological Molecules Flashcards

1
Q

Structure of an amino acid

A

Check

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

What is an amine group?

A

The H-N-H part

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

What is a carboxyl group?

A

The O=C-OH part

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

How does an amino acid become polar?

A

The OH on the carboxyl group dissociates and joins the H-N-H on the amine group, forming ammonia which is positive. This also leaves a negative charge on the carboxyl group

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

What reaction breaks up 2 amino acids?

A

Hydrolysis, requiring H2O

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

What reaction joins up 2 amino acids?

A

Condensation, releasing H2O

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

What is the bond between two amino acids called?

A

peptide

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

What is the test for proteins?

A

Biuret test

  • crushed in distilled water and filter
  • add NaOH and 1% CuSO4
  • light blue to lilac
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which forces join up proteins and what are they between?

A

Disulfide bridges - S and S
Ionic bonds - oppositeley charged stuff
Hydrogen bonds - H and O/N
London forces - everything

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

How do you break each of these bonds?

A

Hydrogen - heat
Ionic - change in pH
Disulfide - reducing agent
London - heat

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

order the bonds by strength high to low

A

Disulfide
Ionic
Hydrogen
London

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

what is primary structure?

A

the sequence of amino acids in a chain.

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

what is secondary structure?

A

the 3-D shape of the protein. Can either be a beta-pleated sheet or alpha helix

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

what is tertiary structure?

A

the overall 3-D shape, e.g fibrous or globular

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

which structure is disrupted by breaking one of the intermolecular forces?

A

tertiary

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

what is the induced fit theory?

A

as the substrate comes close to the active site, it forms bonds that change its tertiary structure. This causes a strain on the bonds of the substrate, making them easier to break.

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

what factors affect the rate of an enzyme-controlled reaction?

A
  • enzyme concentration
  • substrate concentration
  • pH
  • temperature
  • competitive and non-competitive inhibitors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is ATP made of?

A

one adenine molecule, connected to a ribose sugar, connected to 3 phosphate groups

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

compare the structure of atp with a nucleotide

A
  • atp always has adenine, nucleotide can have any base including adenine
  • atp has ribose sugar, nucleotide has any deoxyribose sugar
  • atp has 3 phosphate groups, nucleotides have one
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what happens to atp to release energy?

A

atp gets hydrolysed, as the covalent bond between the second and third phosphate groups is very unstable

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

what enzyme hydrolyses atp?

A

atp hydrolase

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

what is produced when atp is hydrolysed?

A

adenine diphosphate (adp) and a phosphate

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

what is required for the hydrolysis of atp?

A

water

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

how can adp be converted back to atp and what is required?

A

condensation reaction, requires:

  • adp
  • phosphate group
  • atp synthase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
when is atp synthesised?
photosynthesis or respiration
26
what can the inorganic phosphate group that is released be used for?
phosphorylate other compounds, making them more reactive
27
what is a monosaccharide
the monomers from which larger carbohydrates can be made
28
name three monosaccharides
- glucose - galactose - fructose
29
draw alpha glucose
check
30
draw beta glucose
check
31
what is the difference between alpha glucose and beta glucose?
- in alpha glucose, on the right the H is on the top and the OH is on the bottom - in beta glucose, on the right the OH is on the top and the H is on the bottom
32
what reaction joins two monosaccharides into a disaccharide?
condensation reaction that releases water
33
what bond is formed between two monosaccharides in a disaccharide?
glycosidic
34
what is maltose made from?
glucose and glucose
35
what is sucrose made from?
glucose and fructose
36
what is lactose made from?
glucose and galactose
37
what is a polysaccharide?
lots of monosaccharides
38
what are the two polysaccharides made from alpha glucose?
- glycogen | - starch
39
compare starch and cellulose
- starch made of alpha glucose, cellulose made of beta glucose - inverted shape, position of hydrogen and hydroxyl groups on carbon 1 inverted
40
why are the sugars called "reducing sugars"?
an OH group makes it reducing, so when they become disaccharides the OH group becomes an O, except for in maltose
41
general structure of glycogen
- forms 1-4 glycosidic bonds and 1-6 bonds where it branches out - spherical, densely packed
42
general structure of amylose starch
- linear unbranched polymer with 1-4 glycosidic bonds | - coils into an alpha helix, held together by hydrogen bonds
43
general structure of amylopectin starch
- linear, branched polymer with parallel chains with 1-6 glycosidic bonds - forms parallel chains
44
why does starch need to be insoluble?
otherwise would decrease the water potential inside the cell, so water would move in and the cell would become turgid and lyse
45
why do we need amylopectin and glycogen?
amylase can only hydrolyse the terminal glucose, so if there are more branches more terminal glucoses can be hydrolysed at the same time. faster energy release
46
general structure of cellulose
chains that run parallel with hydrogen bonds between them. these form microfibrils which join together to make macrofibrils.
47
how is cellulose's structure good for its function?
microfibrils and macrofibrils are very strong, and make fibres which make good cell walls
48
test for reducing sugars
Benedict's solution goes from blue to brick red in a reducing sugar
49
test for starch
iodine goes from orange to blue/black
50
what is a competitive inhibitor?
an inhibitor that is the same shape as the substrate.
51
graph for competitive inhibitor
check
52
what is a non-competitive inhibitor?
forms intermolecular forces with the allosteric site which changes the shape of the active site meaning the substrate no longer binds.
53
graph for non-competitive inhibitor
check
54
how is a triglyceride formed
when each hydroxyl group on the glycerol combines with a carboxyl group on the fatty acid. this is a condensation reaction which releases 3 H2O molecules
55
what bond is formed between the glyceride and three fatty acids
ester bond
56
saturated fats
- single bonds - straight so can be packed together - solids at room temperature
57
unsaturated fats
- at least one double bond - kinky chain so don't pack closely - oils at room temperature
58
what is a phospholipid compared to a triglyceride?
one of the fatty acids is replaced with a phosphate sugar
59
which part of a p.lipid is hydrophobic and which part is hydrophilic?
- fatty acids are hydrophobic | - polar glycerol phosphate group is hydrophilic
60
test for fats
- emulsion test | - add ethanol, if present emulsion will happen where droplets will be suspended
61
name the 4 important properties of water
- cohesion and surface tension - metabolite - solvent - high specific heat capacity
62
use of hydrogen ions
regulating pH
63
use of iron ions
haemoglobin
64
use of sodium ions
co-transport of glucose and amino acids
65
use of phosphate ions
DNA and ATP
66
function of DNA
carry genetic information
67
function of RNA
transferring genetic information from DNA to ribosomes
68
what makes up a nucleotide
pentose sugar-phosphate backbone with a nitrogen containing organic base
69
what bond joins up two nucleotides
phosphodiester bond
70
compare RNA and DNA
- both have phosphate group - DNA has deoxyribose, RNA has ribose - DNA has a,c,t or g, RNA has a,c,g or uracil - DNA is double helix, RNA is single chain - DNA is pretty long, RNA is pretty short
71
what are ribosomes made of
RNA and proteins
72
How does the Benedict test work?
It contains copper sulfate (hence the blue colour) Reducing sugars contain an aldehyde group or a ketone group These reduce Cu2+ ions to Cu+ ions, forming the brick red copper oxide precipitate
73
what is the difference between secondary structure and tertiary structure?
secondary structure is forces between the amine group of one amino acid and the carboxyl group of another. tertiary structure is forces between the R groups of amino acids
74
properties of fibrous proteins
- parallel polypeptide chains crosslinked - form long fibres or sheets - usually insoluble in water - physically tough - eg collagen, silk and keratin
75
properties of globular proteins
- tightly folded polypeptide chains - form spherical shape - usually soluble, as hydrophobic groups on the inside and hydrophilic groups on the outside - eg enzymes, antibodies and many hormones
76
what is quaternary structure
arrangement of different polypeptide chains and prosthetic groups within a protein
77
what is a prosthetic group
a non amino acid part of a conjugated protein

Biology A Level (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions