Brainscape's Knowledge GenomeTM

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


See full index

Biology AS-Level > Biological molecules > Flashcards

Biological molecules Flashcards

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

Define polymers

A

Large complex molecules of long chains of monomers joined together

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

Define monomers

A

Small basic molecular units

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

Define condensation reaction

A

When 2 molecules join together w/ formation of chemical bond + water molecule

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

Which bond forms btw 2 monosaccharides?

A

Glycosidic bond

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

What makes

Sucrose?

A

Glucose + fructose

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

What makes

Maltose?

A

Glucose

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

What makes

Lactose?

A

Glucose + galactose

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

Define hydrolysis

A

Breaks chemical bond btw monomers using water molecule

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

Outline how to carry out a test for reducing sugars

A
  • Add benedicts reagent to sample + heat in water bath til brought to boil
  • +ve = red ppt
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Outline how to carry out a test for non-reducing sugars

A
  • Add dilute HCl + heat in water bath
  • Neutralise w/ sodium hydrogencarbonate
  • Carry out benedict’s test
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Give examples of reducing sugars

A
  • All monosaccharides
  • Maltose + lactose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define polysaccharide

A

When more than 2 monosaccharides are joined by condensation reaction

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

Outline the structure + function of starch

A
  • Main energy storage in plants - excess glucose
  • Mix of 2 a-glucose
  • Amylose - long unbranched chain, coiled making it compact + good for storage
  • Amylopectin - long branched chain, side branches allow enzymes to break down glycosidic bond easily so glucose released quickly
  • Insoluble so doesn’t affect WP - doesn’t cause water to enter by osmosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Outline the test for starch

A
  • Iodine test
  • Add iodine dissolved in potassium iodide solution
  • +ve = brown-orange to blue-black
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Outline the structure + function of glycogen

A
  • Main energy storage in animals - excess glucose
  • Polysaccharide of a-glucose
  • Loads of side branches - stored glucose easily + quickly released
  • Compact - good for storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Outline the structure + function of cellulose

A
  • Major component of cell walls in plants
  • Long unbranched chains of b-glucose
  • Cellulose chains linked by H bonds forming strong fibres - microfibrils, provides structural support
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Outline the structure of a triglyceride

A
  • 1 glycerol attached to 3 fatty acids
  • FA - have long tails made of hydrocarbons, tail is hydrophobic so insoluble in water
  • All FA have same basic sturcture but diff. hydrocarbon tail
18
Q

Which bond forms btw FA + glycerol?

A

Ester bond

19
Q

What are the 2 types of FA?

A
  • Saturated - don’t have double bonds
  • Unsaturated - have at least 1 double bond, chain kinks
20
Q

Outline the structure of a phospholipid

A
  • 1 glycerol, 2 FA + 1 phopshate group
  • Phosphate group = hydrophilic
  • FA = hydrophobic
21
Q

Outline how the structure of triglyceride is related to its function

A
  • Used as energy storage molecules
  • Long hydrocarbon tails of FA contains lots of chemicial energy - loads of energy released when broken down
  • Insoluble - don’t affect WP (clumps together as insoluble droplets w/ tail facing inwards)
22
Q

Outline how the structure of phospholipid is related to its function

A
  • Make up bilayer of cell membrane
  • Heads are hydrophilic + tail hydrophobic so form double layer w/ head facing out
  • Centre of bilayer is hydrophobic so water soluble substances can’t pass through
23
Q

Outline the test for lipids

A
  • Emulsion test
  • Shake sample w/ ethanol for min so it dissolves then add water
  • +ve = milky emulsion
24
Q

Which bond forms btw 2 aa?

A

Peptide bond

25
Q

Describe the structure of a protein

A
  • 1º - seq aa in polypeptide chain
  • 2º - H bonds form btw aa, coil into a helix or fold into b pleated sheets
  • 3º - Coiled + folds further, more bonds form: H, ionic + disulfide bridges
  • 4º - several diff polypeptide joined together by bonds, forms final 3D structure
26
Q

Outline the structure + function of enzymes

A
  • Roughly spherical due to tight folding of polypeptide chain
  • Soluble
  • Roles in metabolism
27
Q

Outline the structure + function of antibodies

A
  • Involved in immune system
  • Made of 2 light polypeptide chains + 2 heavy polypeptide chains bonded
  • Have variable regions - aa seq varies
28
Q

Outline the structure + function of transport proteins

A
  • Contain hydrophilic aa causing protein to fold up + form channels
  • Transport molecules + ions across membranes
29
Q

Outline the structure + function of structural proteins

A
  • Physically strong
  • Consist of long polypeptide chains lying parallel to each other w/ cross links btw
  • Include keratin + collagen
30
Q

Outline the test for proteins

A
  • Biuret test
  • Solution needs to be alkaline so add sodium hydroxide solution
  • Add copper sulfate solution
  • +ve = turns from blue to purple
31
Q

What is the role of an enzyme and how does it carry out its role?

A
  • Speeds up ROR by lowering the Ea
  • If 2 substrates are joining, attaching to enzyme holds them close together, reducing repulsions so bond easily
  • If catalysing a breakdown, fitting into AS puts strain on bond on substrate so substrate breaks up more easily
32
Q

Outline the induced fit model

A
  • As substrate binds the AS changes shape slightly
  • Forming enzyme-substrate complex
33
Q

What happens to the ROR when temperature is increased?

A
  • Inc
  • More kinetic energy, molecules move faster
  • Enzymes more likely to collide w/ substrate
34
Q

What happens to the ROR when temperature is too high?

A
  • Dec
  • Enzyme molecules vibrate more, breaking some bonds
  • AS changes shape + enzyme + substrate no longer fit
  • Enzymes denature
35
Q

What happens to the ROR when the pH is too low or too high?

A
  • Dec
  • H+ + OH- mess w/ H + ionic bonds
  • Enzyme denatures
36
Q

What happens to the ROR when the conc of enzymes are inc?

A
  • Inc - more likely to collide w/ substrate forming ES complex
  • However no. substrate is limited so inc enzyme conc has no further effect
37
Q

What happens to the ROR when the conc of substrate inc?

A
  • Inc - more likely to collide w/ enzyme uptil point where all AS are saturated so inc substrate conc has no further effect
  • Substrate conc dec overtime so if no other variables are changed, ROR dec over time
38
Q

Outline how competitive inhibitors inhibit enzyme activity

A
  • Comp inhibitors have similar shape to substrate
  • Bind to AS but no reaction takes place
  • Block AS so no substrate can fit
39
Q

Outline how non-competitive inhibitors inhibit enzyme activity

A
  • Bind away from AS
  • AS changes shape so substrate can no longer bind
40
Q

Outline an experiment into measuring how fast the product of a reaction is made

A
  • Catalase catalyses breakdown of hydrogen peroxide into water + oxygen - oxygen displaces water in cylinder
  • Set up boiling tube w/ same vol + conc of hydrogen peroxide, add buffer solution
  • Boiling tube w/ bung attached to delivery tube in upside down measuring cyliner in water
  • Put each boiling tube in diff temp water baths
  • Add same vol + conc of catalase then attach bung
  • Record how much oxygen is produced
41
Q

Outline an experiment into measuring how fast the substrate is broken down

A
  • Amylase catalyses breakdown of starch to maltose
  • Drop of iodine in potassium iodide in well on spotting tile
  • Known conc amylase + starch mixed in test tube
  • Drop mixture in tile at regular intervals + observe colour change
  • Can see how fast amylase is working by recording how long iodine sol no longer turns black
  • Repeat at diff conc of amylase

Biology AS-Level (4 decks)

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