Topic 1 - Bio Molecules Flashcards

(66 cards)

1
Q

What causes water to be a dipole

A

The electrons between the covalent bonds are closer to oxygen, giving the O side a negative charge and the H2 side a positive charge

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2
Q

What is the significance of the following properties of water:
1) high specific heat capacity
2) cohesion and adhesion
3) latent heat of vaporisation
4) ice is less dense than water
5) transparency

A

1) means water is available to organisms across a wide range of temperatures
2) coh- water molecules flow together adh- water is attracted to move up walls
3) used in cooling effect using body heat to vaporise water
4) ice floats to surface to insulate habitat beneath
5) light can penetrate so plants and algae can photosynthesise

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3
Q

What are sodium ions used for?

A

Nerve impulses, uptake of glucose and amino acids into gut, kidney tubule function

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4
Q

What are phosphate ions used for?

A

Strengthen bones, used in ATP, DNA and RNA

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5
Q

What are iron ions used in?

A

Haemoglobin

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6
Q

What are iodine ions used for?

A

Production of thyroxine, involved in IQ levels and development
Iodine = trace element only need small amount daily

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7
Q

What are some monosaccharides?

A

Trioses,
Pentoses e.g ribose and deoxyribose, Hexoses e.g fructose, glucose and galactose

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8
Q

What is the formula for glucose and the difference between beta and alpha glucose?

A

Formula: C6 H12 O6
Alpha = OH group on first carbon is on bottom
Beta = OH group on first carbon is on top
ABBA

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9
Q

What are the disaccharides and what are they composed of?

A

Maltose - 2 alpha glucoses
Sucrose - alpha glucose and fructose
Lactose - alpha glucose and galactose

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10
Q

What is the reaction between glucose and what bond does it form? How do you break down these bonds?

A

A condensation reaction that forms glycosidic bonds. Bonds are broken down in a hydrolysis reaction

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11
Q

What are features of polysaccharides? What are the 3 main polysaccharides?

A

Larger molecules
Compact
Chemically inert
Lots of glycosidic bonds
3 main polysaccharides are starch, glycogen and cellulose
Others are : chitin and murein

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12
Q

What are the components of starch and features of them?

A

Amylose - long chain of alpha glucose twisted into alpha helix shape by hydrogen bonds contains only 1,4 glycosidic bonds
Amylopectin - branches chain of alpha glucose contains both 1,4 and 1,6 glycosidic bonds

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13
Q

What is the test for reducing sugars?

A

Add Benedict’s solution and heat at 80• for 5 mins. Copper precipitates to form a red colour from original blue

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14
Q

What is the test for non-reducing sugars?

A

Heat with HCl at 80•
Cool and neutralise (with sodium hydrogen carbonate)
Test with Benedict’s
Should turn from blue to red

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15
Q

What is the test for starch?

A

Add potassium iodide solution
Will turn from brown to blue/black

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16
Q

What is the structure and features of glycogen?

A

Polymer of alpha glucose
Animal energy reserve
Found in muscles and around liver
Very compact grain - more 1,6 glycosidic bonds
Chemically inert unless broken into glucose by hydrolysis
Insoluble

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17
Q

What enzyme breaks down starch and how does that then become glucose?

A

Starch is broken down by amylase into maltose
Maltose is broken down by maltase into glucose

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18
Q

What are features and the structure of cellulose?

A

Is a polymer of beta glucose
Creates a straight chain of microfibril
Is a component in the cell wall- microfibril is layered and held together by hydrogen bonds
Only 1,4 glycosidic bonds but the glucose molecules undergo an alternating 180• flip during bonding

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19
Q

What are features and the structure of cellulose?

A

Is a polymer of beta glucose
Creates a straight chain of microfibril
Is a component in the cell wall- microfibril is layered and held together by hydrogen bonds
Only 1,4 glycosidic bonds but the glucose molecules undergo an alternating 180• flip during bonding

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20
Q

What structure are lipids made out of? And what part of this is hydrophobic

A

Triglycerides
The fatty acid tails are hydrophobic

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21
Q

What are the two components of a fatty acid?

A

The carboxyl group and the hydrocarbon tail

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22
Q

What is the reaction between a glycerol and a fatty acid and what bond does it form?

A

A condensation reaction that forms a ester bond

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23
Q

What happens is a fatty acid is unsaturated?

A

It has less hydrogen atoms due to a carbon-carbon double bond which causes a kink in the chain

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24
Q

What happens is a fatty acid is unsaturated?

A

It has less hydrogen atoms due to a carbon-carbon double bond which causes a kink in the chain which makes the lipid a liquid (oil)

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25
What are the uses of lipids?
Energy reserve used after carbohydrates in both plants and animals Used in hormone production Insulation Rich in vitamins and aids uptake Protects vital organs Buoyancy
26
What are the two types of unsaturated fatty acids acids and what is the difference between them?
Monounsaturated - single C=C bonds Polyunsaturated - multiple C=C bonds
27
What is a phospholipid and where is it found?
Made up of 1 glycerol, 2 fatty acid tails and 1 phosphate group Make up cell membrane in a phospholipid bilayer
28
What is a glycolipid and what does it do?
1 glycerol, 2 fatty acid tails and 1 carbohydrate Hold cells together in a tissue and act as a receptor for hormones
29
What is cholesterol and what is it used for?
4 hydrocarbon rings and 1 hydrocarbon tail It fits in cell membrane and strengthens it and helps make hormones
30
What is the test for a lipid?
Emulsion test - add ethanol and shake add distilled water and shake should form a cloudy emulsion
31
What are the uses of protein?
Make up enzymes that catalyse reactions Make up antigens that act as immunological markers Collagen which is a component of tendons Coats cholesterol to form lipoprotein Make antibodies Make pigments e.g. haemoglobin
32
How many naturally occurring amino acids are there? How many do humans gain from their diet? What foods provide these?
20 naturally occurring Humans gain 10 from their diet Meats provide all 10, different plants provide a different 8, pulses, nuts and grains provide all 10 when combined
33
What 3 groups do amino acids contain?
Amine group, carboxyl group and variable group
34
What reaction occurs between 2 amino acids, what bond does it form and what does it produce?
A condensation reaction which forms a polypeptide bond. Produces a dipeptide
35
What is the primary structure of protein?
The sequence of amino acids in polypeptides
36
What is the secondary structure of protein?
Either an alpha helix or a beta pleated sheet is formed due to hydrogen bonds between amino acids
37
What is the tertiary structure of protein?
A globular molecule is created due to bonds between R groups using: Hydrogen bonds Ionic bonds Dipeptide bridges - only with [Cys] Hydrophobic interaction
38
What is the quaternary structure of protein?
A protein consists of 2+ polypeptides joined together by hydrogen bonds E.g. Haemoglobin consists of 2 alpha and 2 beta polypeptides
39
What is in the middle of the polypeptides making up Haemoglobin?
A haem group (prosthetic group)which contains 1 iron ion
40
How many oxygen atoms can one Haemoglobin carry?
8 oxygen atoms Each haem can bind to 1 oxygen molecule (diatomic) Each Haemoglobin contains 4 haems
41
What is collagen made up of
3 interwoven polypeptide strands Each strand is made up of chains which are joined together in a staggered pattern to strengthen stand
42
What is the test for a protein?
Add biuret reagent Will turn from blue to purple
43
What reactions do enzymes catalyse?
Metabolic reactions Intracellular and extracellular
44
What reactions do digestive enzymes catalyse?
Hydrolysis reactions
45
What are the two enzymes that join nucleotides to make a polymer
DNA polymerase RNA polymerase
46
What is formed when a substrate fits into an enzymes active site?
An enzyme-substrate complex
47
What bonds do the substrates form with the active site and why?
Temporary bonds Very few so they are easily broken
48
What are the 3 steps of enzymes catalysing reactions?
1) substrate collided with sufficient energy to form product molecules 2) free energy of products must be less than that of substrate 3) may need energy to start reaction
49
What does the induced fit model state?
Enzymes are not complementary to substrate, substrate changes active site This change weakens bonds in substrate which lowers the activation energy
50
Put ionic bonds, hydrogen bonds and disulphide bonds in order of strength (weakest to strongest)
Hydrogen, ionic, disulphide
51
Write a statement about the enzymes active site
Enzymes have an active site that can become complementary to a specific substrate
52
What are the 3 ways of calculating rate?
Product/time Decrease in substrate/time 1/reaction time
53
What factors affect rate of enzyme reactions?
Concentration of substrate Concentration of enzyme Temperature pH Presence of inhibitors
54
What is a nuceotide of DNA composed of?
A phosphate group, pentose sugar (deoxyribose), and an organic nitrogenous base
55
What are the two kinds of bases and 2 of each?
Purines - adenine and guanine Pyrimidines - cytosine and thymine
56
What are the phosphodiester bonds in DNA between?
Carbon 3 of the pentose sugar and the phosphate group
57
What is formed due to the phosphodiester bonds? How does this help DNA?
Sugar-phosphate backbone - makes DNA more stable and more resistant to mutations
58
What bonds form between complementary bases? What does this do for DNA?
Hydrogen bonds. 2 between A-T. 3 between C-G. Makes DNA more stable, bonds can be broken when needed, bonds act as template during replication
59
What shape does DNA form?
A double helix - DNA = anti parallel
60
What is an RNA nucleotide made from?
A phosphate group, a pentose sugar (ribose) with 5 carbons, organic nitrogenous base
61
What are the 3 types of RNA?
Messenger RNA - copies base sequence of coding strand of 1 gene Transfer RNA - carries amino acids to ribosomes Ribosomal RNA - makes up ribosomes
62
What are the components of the nucleus?
Nucleolus - makes rRNA Nuclear pore - let’s mRNA out Nuclear envelope Nucleoplasm
63
Compare RNA and DNA nucleotides
Both contain phosphate groups Both contain 5 carbon pentose sugars Both contain organic nitrogenous bases RNA = ribose DNA = deoxyribose DNA = thymine RNA = uracil
64
Compare DNA and RNA molecules
Both have sugar-phosphate backbones RNA = single stranded DNA = double stranded RNA = shorter than DNA 3 types of RNA RNA = uracil not thymine
65
What are hydrogen ions used for?
They determine the pH of a substance
66
What are hydrogen ions used for?
They determine the pH of a substance