Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > 3.1 Biological molecules > Flashcards

3.1 Biological molecules Flashcards

1
Q

Monomer definition

A

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

Polymer definition

A

Molecules made from a large number of monomers bonded together

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

What is a condensation reaction

A

A reaction that joins two molecules, forming 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
4
Q

Monosaccharide reactions

A

Glucose + Glucose -> Maltose
Glucose + Galactose -> Lactose
Glucose + Fructose -> Sucrose
(All alpha glucose)

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

Glycogen structure

A

1-4, 1-6 glyosidic bonds
Alpha glucose monomers
Large but compact
Highly branched

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

Adaptations of starch

A

Helically coiled so compact (1-4 glycosidic bonds)
Large so cannot move in/out of cell
Osmotically inactive so does not affect water potential
Highly branched so can be hydrolysed quickly by (1-6 glycosidic bonds)
enzymes of respiration to release energy

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

Cellulose structure

A

Long, straight, unbranched chains of Beta glucose (1-4 glycosidic bonds) with hydrogen bonds in between, which individually are weak but together provide strength. These form fibrils

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

Test for reducing sugars

A
  • Crush sample using pestle and mortar and add distilled water
  • Heat in a water bath
  • Add benedict’s solution to test tube
  • Green/yellow/orange/red ppt indicates reducing sugar present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Test for non-reducing sugars

A
  • Set up sample and water bath as normal
  • Add dilute HCl
  • Neutralise with sodium hydrogen carbonate
  • Carry out benedict’s test as normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why add dilute HCl in benedict’s test

A

Hydrolyses bonds between the disaccharides

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

Test for starch

A
  • Crush sample using pestle and mortar and add distilled water
  • Add iodine
  • If it goes blue/black, iodine is present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is a triglyceride formed

A

Three fatty acid chains bind to a glycerol molecule during a condensation reaction forming ester bonds (COCO). Non polar

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

Phospholipid structure

A

2 fatty acid chains and a phosphate ion bonded to a glycerol molecule. Polar. Phosphate head is hydrophilic, fatty acid tail is hydrophobic

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

What is an unsaturated fatty acid chain

A

A fatty acid chain with one or more carbon-carbon double bonds. Will be bent.

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

What is a saturated fatty acid chain

A

A fatty acid chain with no carbon-carbon double bonds. Will be straight.

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

Emulsion test for lipids

A
  • Crush sample using pestle and mortar and add distilled water
  • Add ethanol AND shake
  • Add water
  • White emulsion indicates lipid is present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Amino acid structure

A

. R
H2N - C - COOH
H

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

How many amino acids are common in all oragnisms

A

20

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

Structure of a protein

A

Primary structure - type, number and sequence of amino acids
Secondary structure - folding due to hydrogen bonding resulting in either an a helix or b pleated sheet.
Tertiary structure - 3D folding due to ionic bonds, disulfide bridges and hydrogen bonding
Quaternary structure - Involves two or more polypeptides and can involve prosthetic groups

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

Biuret test

A
  • Crush sample using pestle and mortar and add distilled water
  • Add biuret reagent
  • Colour change from blue to lilac
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is biuret reagent

A

Sodium Hydroxide (NaOH)
Copper Sulfate (CuSO4)

22
Q

What are enzymes

A

Tertiary proteins which lower the activation energy of the reactions they catalyse

23
Q

Induced fit model

A
  • Not initially complimentary
  • Substrate binds to active site
  • Causes active site of enzyme to change shape
  • Enzyme active site becomes complimentary
  • Forming an enzyme substrate complex
  • Distorts bonds of substrate
24
Q

Competitive inhibitors

A

Prevent ESCs from being formed
Similar shape to substrate
Bind to active site of enzyme
Stop substrate from binding to active site
Can be overcome by increasing concentration of substrate

25
Non-competitive inhibitors
Prevent ESCs from being formed Bind to site other than active site Change tertiary structure of enzyme Changing the active site so that it is no longer complimentary to substrate Cannot be overcome by increasing substrate concentration
26
Effect of pH on enzymes
Enzymes have an optimum pH, outside this they become denatured, causing the active site to no longer be complimentary to the substrate, reducing rate of reaction
27
Effect of temperature on enzymes
- All enzymes have optimum temperatures. - At lower temperatures enzymes do not have enough kinetic energy for successful collisions so rate of reaction is reduced. - At higher temperatures, enzymes become denatured, stopping ESCs from forming, reducing rate
28
Effect of substrate concentration of enzymes
As concentration of substrate increases, so does rate as more substrates available to react. Enzymes active sites eventually become saturated, so after a certain concentration, increasing the substrate concentration will have no effect
29
Effect of enzyme concentration
Increases rate as more active sites available to bind to. However after a certain concentration has no effect, because substrates are limitingmfactor
30
Structure of DNA
- Polymer of nucleotides - Each nucleotide is formed from a phosphate group, a nitrogenous base (A,T,C or G) and a deoxyribose sugar - Phosphodiester bonds between adjacent nucleotides - Double helix of two strands held by hydrogen bonds - Hydrogen bonds between complimentary bases (A binds to T, C binds to G)
31
Function and importance of DNA
Codes for sequence of amino acids in the primary structure of proteins Stores genetic information
32
What are ribosomes formed from
rRNA and proteins
33
mRNA vs DNA
mRNA is shorter mRNA is single stranded Both are linear Have a ribose sugar, instead of deoxyribose mRNA has uracil instead of thymine
34
What elements make up carbohydrates
Carbon, Hydrogen and Oxygen
35
a glucose vs b glucose
OH and H swapped around on right carbon
36
Disaccharide
Made up of two monosaccharides, joined together by a glycosidic bond formed by a condensation reaction
37
Where is glycogen found
Muscle and liver cells
38
Why are triglycerides good energy storage molecules
Due to the large ratio of energy-storing carbon-hydrogen bonds compared to the number of carbon atoms
39
Why are triglycerides used as a metabolic water source
Due to the high ratio of hydrogen to oxygen atoms. They can release water if oxidised. Camels.
40
Why do triglycerides no affect the water potential
They are large AND hydrophobic making them insoluble in water
41
Properties of triglycerides
1. Energy storage 2. Metabolic eater source 3. Insoluble 4. Low mass
42
Why is low mass useful as a triglyceride
A lot can be stored without increasing the mass as much as muscle would
43
Semi conservative replication
DNA helicase breaks hydrogen bonds between complimentary base pairs Both strands act as templates Free nucleotides align opposite the complimentary base pairs DAN polymerase joins adjacent nucleotides, forming phosphodiester bonds. Strands are half original, half new DNA
44
Evidence of DNA semi conservative replication
Watson and rick discovered structure of DNA helped by Rosalind franklin Meselson and Stahl proved replication must be semi conservative using heavy nitrogen
45
ATP structure
Nucleotide derivative. Made up of 3 phosphate groups, adenine and ribose.
46
Why is ATP a useful molecule
Hydrolysed in one step so energy is released quickly Can be resynthesised in one step Releases energy in small manageable amounts Phosphorylates molecules to make them more reactive
47
Properties of water
1. Metabolite used in condensation/photosynthesis 2. A solvent in reactions 3. High heat capacity yo buffer temperature change 4. Large latent heat of vaporisation, providing a cooling effect through evaporation 5. Strong cohesion between molecules, supporting water columns and providing surface tension 6. Denser a liquid than a solid, allowing organisms to live under ice
48
Inorganic ions roles
Hydrogen - lowers pH of solution/chemiosmosis Iron - haemoglobin, transport of oxygen Sodium - Cotransport in ileum/action potentials Phosphate - component of DNA/ATP/resting potential
49
Explain how features of DNA and how they're important in semi-conservative replication
1. Weak hydrogen bonds between bases allow two strands to unzip; 2. Two strands, so both can act as templates; may appear in the same feature 3. Complementary base pairing allows accurate replication;
50
Why does DNA polymerase work in opposite directions on either strand
1. DNA has antiparallel strands 2. shape of the nucleotides is different 3. Enzymes have active sites with specific shape; 4. Only substrates with complementary shape can bind with active site of DNA polymerase.
51
Why can nucleotides be only added in the 5' to 3' direction
DNA polymerase Has specific active site Only complimentary to 5' end 5' end different to 3' end
52

Biology (8 decks)

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