biological molecules BAILEY Flashcards

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1
Q

define monomers

A

small molecular unit

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2
Q

define polymerisation

A

process of forming a polymer from many monomers

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3
Q

define a condensation reaction

A

when a monomer is joined to another monomer forming a chemical bond and a molecule of water

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4
Q

define hydrolysis reaction

A

polymers can be broken down into monomers by using water to break chemical bonds

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5
Q

name one monosaccharide

A

glucose

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6
Q

name 3 polysaccharide

A

glycogen
starch
cellulose

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7
Q

name the polymer made out of amino acids

A

polypeptides
(proteins)

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8
Q

name one type of proteins

A

enzymes

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9
Q

name a polynucleotide

A

DNA
RNA

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10
Q

write a method of how to test for reducing sugars
(all monosaccharides all disaccharides)

A
  1. equal volumes of sample and Benedict’s solution
  2. HEAT gently for 5 mins

if the sample stays blue this is the negative result and means there no reducing sugars in the sample

sample could change colour
RED (strongest concentration of sugar)
ORANGE
YELLOW
GREEN

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11
Q

Name one issue with using Benedict’s to test for reducing sugars

A

it’s semi quantitative
colours can be subjective

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12
Q

What is a more accurate way to measure the amount of reducing sugar

A

use a colourimeter to measure how much light passes through the sample

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13
Q

list 2 positives of using a colourimeter

A

it is quantitative
standardises

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14
Q

when testing how much sugar there is in a precipitate after drying and filtering it
What does the mass mean

A

more mass = more reducing sugars

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15
Q

what elements are carbohydrates made up out of

A

C H O

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16
Q

in a condensation reaction with 2 monosaccharides what is formed

A

disaccharide

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17
Q

name one disaccharide

A

sucrose
maltose
lactose

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18
Q

what is the general formula for monosaccharides

A

CnH2nOn

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19
Q

name 3 monosaccharides

A

glucose
galactose
fructose

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20
Q

name 2 reducing sugars

A

maltose
lactose

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21
Q

name the 2 isomers of glucose

A

beta glucose
alpha glucose

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22
Q

state the formula for hexose

A

C6H12O6

23
Q

what type of sugars are all made out of alpha glucose

A

all disaccharides are made out of alpha glucose

24
Q

give 2 properties of glucose, galactose, fructose

A

soluble
sweet tasting

25
Q

describe how disaccharides are formed

A

disaccharides are 2 monosaccharides joined together by a condensation reaction (forming a new glyosidic bond and a water molecule is released)

26
Q

when the react 2 alpha glucose molecules what is formed as the products

A

alpha glucose + alpha glucose = maltose + water

27
Q

name the reactants to form sucrose + water

A

glucose + fructose

28
Q

name the reactants to form lactose + water

A

galactose + glucose

29
Q

name the reactants to form maltose + water

A

glucose + glucose

30
Q

give the method to test for non reducing sugars

A
  1. heat if the sample stays blue then no reducing sugars are present
  2. add sample and HCl (hydrolyses the glyosidic bond producing a reducing sugar) and boil for 5 mins
  3. add NaHO3 to neutralise the sample
  4. add Benedicts reagent and heat
  5. no non reducing sugars in sample will stay blue as this is a negative result
  6. the colour change will be green, orange, red and then a non reducing sugar is present
31
Q

How are polysaccharides created

A

Polysaccharides are created by condensation reactions between many glucose monomers

32
Q

What are the monomers of starch

A

Alpha glucose

33
Q

In starch what are the bonds between monomers

A

1-6 and 1-4 glycosidic bonds in amlopectin

34
Q

Where is starch located

A

In starch grains in plant cells

35
Q

What is the function of starch

A

Insoluble store of glucose

36
Q

What is the structure of starch

A

2 polymers

Amylose- unbranched helix

Amylopectin- a branched molecule

37
Q

Explain how the structure of starch leads to its function

A

Helix can compact to fit a lot of glucose into a small space

Branched surface increases the surface area for rapid hydrolysis back to glucose

38
Q

What are the monomers of cellulose

A

Beta glucose

39
Q

What are the bonds between the monomers in cellulose

A

1-4 glycosidic bonds

40
Q

What is the function of cellulose

A

Structural strength to cell wall

41
Q

Where is cellulose located

A

Cell wall of plant cells

42
Q

Describe the structure of cellulose

A

Long straight chains of 1-4 glycosidic bond are held together in parallel by many hydrogen bonds (fibrils)

43
Q

Explain how the structure of cellulose leads to its function

A

Many hydrogen bond provide collective strength

44
Q

What are the monomers of glycogen

A

Alpha glucose

45
Q

What are the bonds between monomers in glycogen

A

1-4 and 1-6 glycosidic bonds

46
Q

What is the function of glycogen

A

Insoluble store of glucose

47
Q

Where is glycogen located

A

Muscle and liver cells in animals

48
Q

What is the structure of glycogen

A

A highly branched molecule (has more 1-6 glycosidic bonds)

49
Q

Explain how the structure of glycogen leads to its function

A

Branched structure increases the surface area for rapid hydrolysis (faster hydrolysis back to glucose)
And then glucose provides the respiratory substrate for energy release

Insoluble so does not affect water potential

Helix is compact

50
Q

Describe 2 differences between the structure of cellulose molecule and a glycogen molecule

A

Glycogen is a highly branched molecule but cellulose is in long straight chains

Cellulose is made out beta glucose and glycogen is made out of alpha glucose

Glycogen has 1-4 glycosidic bonds and 1-6 glycosidic bonds but cellulose only has 1-4 glycosidic bonds

51
Q

Describe and explain 2 features of starch that makes it a good storage molecule

A
  • helix can compact to fit a lot of glucose into a small space
  • branched surface increases the surface area for rapid hydrolysis of starch into glucose
52
Q

list the 2 types of lipids

A

Phospholipids
Triglyceride

53
Q

List the 5 roles of lipids

A
  • phospholipids form cell membranes
    (Flexible and transfer soluble substances)
  • energy source
    (When oxidised release 2x the energy of carbohydrates)
  • protection
    (around organs)
  • waxy cuticle/oils from sebaceous glands in the skin
    (Waterproofing)
  • insulation
    (warmth, myelin sheath around neurona allows electrical impulses to be transmitted quickly)
54
Q

list 3 characteristics of lipids

A
  • C H O but less than in carbohydrates
  • insoluble in water so doesn’t affect water potential
  • soluble in organic solvents (alcohol)