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A Level: Biology > Biological Molecules > Flashcards

Biological Molecules Flashcards

(71 cards)

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1
Q

What molecules make up carbohydrates

A

Carbon
Hydrogen
Oxygen

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2
Q

What are 3 properties of monosaccharides

A

Soluble in water
Sweet taste
Form crystals

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3
Q

Name the sugar that has three carbons

A

Triose

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4
Q

What is the difference between alpha and beta glucose

A

Beta glucose’s right OH group on carbon 1 is above the plane of the ring

Alpha glucose’s right OH group on carbon 1 is below the plane of the ring

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5
Q

What is an isomer

A

A molecule that has the same chemical atoms but there arrangement is different

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6
Q

Glucose contains many bonds - what does this mean it can store lot of

A

Stores energy in its covalent bonds

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7
Q

Explain the structure of alpha glucose

A

Forms hydrogen bonds with H/OH groups of water so Is SOLUBLE

  • can be easily transported around the organism in the plasma or phloem
  • bonds contain energy
  • molecules broken down to release energy
  • join together via condensation reaction
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8
Q

Name three disaccharides

A

Maltose
Sucrose
Lactose

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9
Q

Name three monosaccharides

A

Glucose
Fructose
Galactose

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10
Q

How are two disaccharides bonded

A

Covalently bonded together

Contains glycosidic bonds

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11
Q

What three atoms is there in a glycosidic bond

A

Two carbon and one oxygen

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12
Q

What happens during hydrolysis of a disaccharide

A

The OH bond in water breaks- one of the C-O bonds in the glycosidic bond breaks- the h atoms bonds to the o atom and the OH from water bonds to the carbon

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13
Q

What happens when two glucose molecules bond together

A

React to from maltose
Condensation reaction
Produces water
Glycosidic bond forms

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14
Q

What catalysed the hydrolysis of maltose

A

Maltase

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15
Q

Similarities between lactose and maltose

A

Both contain glucose
Contain two 5 C rings
Both have 1-4 glycosidic bond

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16
Q

Differences between lactose and maltose

A

Lactose contains beta glucose
Maltose has alpha glucose

L has beta glycosidic bond
M has alpha glycosidic bond

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17
Q

What is starch made from

A

Two different polysaccharides:
Coiled amylose
Coiled and branched amylopectin

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18
Q

Where is the glycosidic bond in amylose

A

Below the plane of the ring

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19
Q

What type of bond is amylose

A

Alpha 1-4 glycosidic bond

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20
Q

What type of bond does amylopectin have

A

Alpha 1-4 and alpha 1-6 glycosidic

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21
Q

What type of bond In glycogen

A

Alpha 1-4 and alpha 1-6 glycosidic bond

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22
Q

How is glycogen different to amylopectin

A

There is more branching points in glycogen than there is in amylopectin

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23
Q

Why does glycogen have branched

A

So it can be rapidly hydrolysed by enzymes

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24
Q

Name three properties of glycogen

A

Insoluble
Compact
Energy dense

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25
Starch v glycogen Where is it found
S- stores as grains- glucose store in PLANTS G- sorted as granules- ANIMALS
26
Starch v glycogen Name of the monomer that forms the polymer
S-Alpha glucose | G- alpha glucose
27
Starch v glycogen Name of the bond
Starch- amylose- alpha 1-4 glycosidic bond -amylopectin- alpha 1-4 1-6 glycosidic bond Glycogen- alpha 1-4 and 1-6 glycosidic bond
28
What is the stored alpha glucose used for
Respiration
29
How do the structures and properties of glycogen and starch relate to their function
- compact can store lots of energy (stored in a small volume) - metabolically inactive: don’t take part in metabolic reactions - insoluble in water - chain molecules- glucose held in chain and is hydrolysed or built up by enzymes - amylopectin and glycogen are branched
30
Why is it that animals have a faster metabolic rate
Have significantly more branching points
31
What are two structural properties of cellulose
High tensile strength and insoluble
32
What is the function of cellulose
To give strength to resist osmotic pressure
33
what type of glucose does Celulose have
Beta glucose
34
Name of the bond in Celulose
Beta 1–4 Glycosidic bond
35
How are the Glycocidic bonds in Celulose formed
Alternate beta glucose molecules rotate 180° which makes long straight chains
36
What do you cellulose molecules joined together to form
Microfibrils which are cross-linked by hydrogen bonds
37
What type of molecule is a lipid
They are macromolecules not polymers
38
What atoms make up lipids
Carbon hydrogen and oxygen | Less oxygen to carbon atom more hydrogen per carbon atom (than in carbohydrates)
39
How are triglyceride and phospholipid molecules Similar
Contain a glycerol molecule attached to fatty acid chains
40
What is the purpose of triglycerides
And energy storage and source can be hydrolysed to generate ATP Insolation e.g. Blubber in Wales Protection a vital organs
41
What is the function of a phospholipid
To make plasma membrane
42
What is the purpose of sterols
Some hormones are made from sterols
43
What are triglycerides compose from
One molecule of glycerol linked to 3 fatty acid’s
44
Describe the structure of fatty acid chain
A carboxylic acid group at one end and long hydrocarbon chain with between 12 to 20 carbon is in it
45
What are the two types of fatty acid’s
Saturated and unsaturated
46
What does unsaturated mean What effect does this have
There is a double bond Puts a kink in the molecule and the molecules can’t pack as closely together
47
Describe the structure of glycerol
OH
48
Explain how the fatty acids join to the glycerol
Each hydroxyl group in the glycerol joins with the carboxyl group on the fatty acid
49
What happens when a triglyceride forms
Condensation reaction Three Ester bonds are made As are three molecules of water
50
How are lipids respired to make ATP
Lipids are hydrolysed into fatty acids and glycerol | These are then respired to give ATP
51
What is metabolic water
The water that is produce when glycerol and fatty acids respire
52
Explain the structure of phospholipid
A glycerol 2 fatty acids A phosphate group
53
Which part of the phospholipid is hydrophobic and hydrophilic
Phosphate group is hydrophilic Fatty acids are hydrophobic
54
What does surfactants
When the phosphate head tuck into the water and the fatty acid tails sticking out of the water - they sit on the water surface
55
What is a bilayer
Form structures based on a two layered sheet formation
56
Name an example of a steroid alcohol
Cholesterol
57
Describe the structure of cholesterol
Four carbon based ring structure
58
What is the job of cholesterol
Regulates the fluidity and maintains the stability of the membrane
59
Where does cholesterol sit
Between the hydrophobic fatty acids tails of the phospholipids
60
What else is made from cholesterol
Hormones
61
Can cholesterol pass through the bilayer
Yes they diffuse through
62
What does a qualitative test do
Tests for the presence or absence of a particular biological molecule
63
Disadvantage of a qualitative test
Does not tell you the concentration of a particular biological molecule
64
What is the test for starch
Iodine solution Black/blue
65
Test for reducing sugar
Benedicts solution (Must be shaken and heated) Red- present Blue- not
66
Test for non reducing sugar
Boil with HCL Neutralise with sodium carbonate Repeat benedicts test Red-present Blue-not
67
Test for protein
Biuret reagent Shake Lilac - proteins
68
Test for lipids
``` Emulsion test Crush sample add ethanol Shake Pour into water ``` Lipid is present- cloudy white emulsion
69
What is a colorimeter
A device that shines a beam of light through a sample A photoelectric cell then picks up the light that has passed through The sample is placed in a cuvette the between the light and the cell
70
The more sugar present...
The more copper surface used up Less light absorbed More transmitted
71
How can a colorimeter be calibrated
Using a red filter Zero colorimeter using distilled water or Unreacted benedicts

A Level: Biology (18 decks)

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