1A Biological Molecules

Question 1

What are carbohydrates made from?

Answer 1

Monosaccharides such as glucose, fructose and galactose

Question 2

Carbohydrate condensation reaction products?

Answer 2

(Glycosidic Bond ) and water released

Question 3

Examples of carbohydrate condensation reactions

Answer 3

Glucose + fructose -> sucrose

Glucose + galactose -> lactose

2 monosaccharides-> disaccharide

Question 4

Alpha vs Beta glucose

Answer 4

H
OH

OH
H

Question 5

Hydrolysis reaction in carbohydrates

Answer 5

Break glycosidic bond by adding water

Polymers into monomers

Question 6

Reducing sugars test

Answer 6

Heat with Benedicts
Turns brick red

B-r

Question 7

Non reducing sugars test

Answer 7

Add dilute hcl
Heat
Neutralise with sodium hydrogen carbonate 
Heat with Benedicts
Turns brick red

B- r

Question 8

Starch test

Answer 8

Add iodine dissolved in potassium iodide solution

Borneo orange - blues black

Question 9

What is formed when 2 monosaccharides join by a condensation reaction?

Answer 9

Polysaccharides

Question 10

Purpose of starch in plants

Answer 10

• main energy store in plants
• stores excess glucose so when the plant is low the stored starch can get to the glucose . Starch is a mixture of 2 alpha glucose polysaccharides - amylose and amylopectin

Question 11

Amylose

Answer 11

Long unbranched coiled and compact alpha helix

Question 12

Amylopectin

Answer 12

Long unbranched side branches allow enzymes to get at glycosidic bonds easier so glucose can be released quicker

Question 13

Advantages of starch being insoluble

Answer 13

Doesn’t affect WO so doesn’t cause water to enter by osmosis which would make them swell- so good for storage

Question 14

Purpose of glycogen in animal cells

Answer 14

(Main energy store in animals)
-stores excess glucose as glycogen ( alpha)

• similar structure to amylopectin except it has more branches so stored glucose can be released more quickly
• compact - good for storage
• rapid hydrolysis

Question 15

Cellulose

Answer 15

Long unbranched chains of beta glucose

Bonded molecules of B forms straight chains

Cellulose chains linked together by hydrogen bonds to form strong fibres called microfibrils

• strong fibres mean cellulose provides structural support for cells

Question 16

What is a triglycerides

Answer 16

A lipid

Question 17

Structure of a triglyceride

Answer 17

G
L     —fatty acid 
Y
C
E     — fatty acid
R
O   — fatty acid 
L

Question 18

What’s a fatty acid

Answer 18

Hydrocarbon chain - hydrophobic so insoluble in water

Question 19

How is a triglyceride formed

Answer 19

Condensation reaction when 3 fatty acids join to a glycerol when water is released

Ester bonds

Question 20

Saturated HC

Answer 20

NO double bonds between carbon atoms in the HC chain

Question 21

Unsaturated HC

Answer 21

At least ONE double bond between carbon atoms in the HC chain

Question 22

Phospholipid

Answer 22

Similar to triglyceride

                         G
                          L —- fatty acid 
                          Y
                         C
                         E —- fatty acid 
                         R
                          O
Phosphate —— L
Group

Question 23

Phospholipid description

Answer 23

Found in cell membranes

Fatty acid replaced by phosphate group

Phosphate group is hydrophilic ( attracts water)

Tails are hydrophobic repel water

Question 24

Triglycerides functions

Answer 24

Energy store molecules

1. Long HC tails contain lots of energy which is released when they’ve broken down
2. Insoluble - doesn’t affect WP and cause water to enter the cell by osmosis making them swell- clump together as insolvable droplets in cells are hydrophobic so face I waters shielding from water with glycerol heads

Question 25

Phospholipid function

Answer 25

- make up bilateral of cell membranes - hydrophilic heads and hydrophobic tails- forming a double layer - centre is hydrophobic so water soluble substances can’t pass through easily

Question 26

Emulsion test for lipids

Answer 26

- Shake with ethanol - pour into water -> milky emulsion

Question 27

Proteins are made from long gains of amino acids

Answer 27

Monomers = amino acids Two amino acids joining together = dipeptide Polypeptide = more than two amino acids Proteins = more than one polypeptide

Question 28

Amino acid

Answer 28

``` R | H2N—C—COOH | H ``` 20 amino acids

Question 29

Polypeptide bonds formation

Answer 29

Formed by condensation reactions of amino acids - water released - peptide bond formed

Question 30

Primary structure

Answer 30

Sequence of amino acids in the polypeptide chains

Question 31

Secondary Structure

Answer 31

Polypeptide chain doesn’t remain flat and straight - hydrogen bonds form between amino acids in the chain - coils in a helix Or - fold into b pleated sheet

Question 32

Tertiary structure

Answer 32

Coiled and folded further . - more bonds form: - hydrogen - ionic bonds - disulphides bridges - final 3D structure

Question 33

Quaternary Structure

Answer 33

- made of several different polypeptide chains held together by bonds - it’s the way they are assembled together - final 3D Structure

Question 34

Protein functions

Answer 34

1. Enzymes - spherical due to tight folding of the polypeptide chains. Soluble. Metabolise and synthesise. 2. Antibodies - are involved in the immune response - 2 light and 2 heavy polypeptide chains. Variable regions. 3. Transport proteins - channel proteins 4. Structural proteins - strong - long polypeptide chains lying parallel with cross links - keratin and collagen

Question 35

Biuret test for proteins

Answer 35

Add sodium hydroxide Add copper surface solution Protein = purple No protein = blue

Question 36

Enzymes

Answer 36

- Catalysts - can affect structures in an organism - can be intracellular - are proteins - have an active site - highly specific due to tertiary structure

Question 37

Activation energy

Answer 37

Amount of energy that needs to be supplied to the chemicals before the reaction will start

Question 38

Enzymes lowering AE

Answer 38

- make the reaction happen at a lower temp => speeds up ROR ....

Question 39

Lock and key

Answer 39

....

Question 40

Induced fit

Answer 40

....

Question 41

Enzymes and tertiary structure

Answer 41

....

Question 42

Temp and enzymes

Answer 42

....

Question 43

pH and enzymes

Answer 43

....

Question 44

Conc and enzymes

Answer 44

...

Question 45

Substrate conc and enzyme

Answer 45

...

Question 46

Competetive inhibition

Answer 46

....

Question 47

Non competitive inhibition

Answer 47

...

Question 48

Enzyme controlled reactions

Answer 48

1

Question 49

2

Answer 49

3

Question 50

4

Answer 50

5