Biological molecules

Question 1

Why is water important?

Answer 1

Water is reactant important in reactions such as hydrolysis and is a solvent most reactions take place in a solvent so water is important

Question 2

Water

Answer 2

Transports substances as its liquid and solvent and has a high specific heat capacity making it good for temp control.

Question 3

Water structure

Answer 3

One atom of oxygen joined to two atoms of hydrogen by shared electrons- water is polar it has a partial negative charge on one side and positive on the other attraction between water called hydrogen bonding

Question 4

What does hydrogen bonding give water?

Answer 4

Gives water a high specific heat capacity as they can absorb a lot of energy so is good in habitats aswell as a high latent heat of evaporation means water is great for cooling things

Question 5

What are carbohydrates made off?

Answer 5

They are made from monosaccharides which are the monomers that make up the carbohydrates all have carbon hydrogen and oxygen

Question 6

Monosacharide bonding

Answer 6

Glycosidic bonds, hydrogen atom on one monosaccharide bonds to the hydroxyl group on the other releasing a molecule of water; condensation reaction reverse is hydrolysis

Question 7

Starch

Answer 7

Main energy source in plants
Amylose- Long, unbranched chain of alpha glucose coiled structure compact good for storage
Amylopectin- Long, branched chain side branches allow enzymes to get at the glycosidic bonds quickly so glucose can be released quickly

Question 8

What is glycogen?

Answer 8

The main energy storage material in animals polysaccharide of alpha glucose has many more side branches means that stored glucose can be released quickly and compact

Question 9

Cellulose

Answer 9

Long unbranched chain of beta glucose cellulose chains linked together by hydrogen bonds to form microfibrils.

Question 10

Lipids: Triglycerides

Answer 10

They are macromolecules large molecular mass contain carbon, hydrogen and oxygen one molecule of glycerol with three fatty acids attached tails are hydrophobic. Contain ester bonds which is fromed by the condensation reaction and is called estrefication.

Question 11

Saturated Fatty acids

Answer 11

They dont have any double bonds between their carbon atoms. The acid is saturated with hydrogen. Formula = CnH(2n+1)

Question 12

Unsaturated Fatty acids

Answer 12

They have at least one double bond between the carbon atoms causing them to kink

Question 13

Phospholipids

Answer 13

They are found in the cell membranes of all eukaryotes and prokaryotes and make up the phospholipid bilayer controls what leaves and enter the cells. Centre of bilayer is hydrophobic so water soluble substances cannot easily pass through it so acts as a barrier

Question 14

Cholesterol

Answer 14

Hydrocarbon ring strucutre attached to a hydrocarbon tail has a polar hydroxyl group in animals is strengthens the cell membrane small and flattened allows it to fit between the bilayer bind to the hydrophobic tails making them pack more closely together less fluid.

Question 15

What are proteins made off?

Answer 15

They are made of long chains of amino acids and are polymers and amino acids are the monomers of a protein dipeptide is formed when two amino acids join and more than two a polypeptide and a protein is made of one or more polypeptides

Question 16

Primary structure

Answer 16

This is the sequence of amino acids in the polypeptide chain. Different proteins have different sequences of amino acids in their primary structure. A change in just one amino acid may change the structure of the whole protein.

Question 17

Secondary structure

Answer 17

Polypeptide chain doesn’t remain flat and straight. Hydrogen bonds form between nearby amino acids in the chain. This makes it either coil into an alpha helix or fold into a beta pleated sheet

Question 18

Tertiary structure

Answer 18

To coiled or folded chain of amino acids is often coiled and folded further. More bonds form between different parts of the polypeptide chain. For proteins made from a single polypeptide chain, the tertiary structure forms their final 3D structure

Question 19

Quaternary structure

Answer 19

The way the polypeptide chains are assembled together eh haemoglobin is made from four polypeptide chins linked together

Question 20

Globular protein

Answer 20

• Round and compact
• Soluble so easily transported in fluid
• Haemoglobin conjugated protein
• Insulin hormone by pancreas

Question 21

Fibrous proteins

Answer 21

• Tough and rope shaped
• Insoluble and strong
• Structural proteins don’t react with much

Question 22

Collagen

Answer 22

• Found in animal connective tissue- very strong molecule Minerals bind and make it a very strong molecule

Question 23

Keratin

Answer 23

• Found in many external structures of animals such as skin and nails and horns
• It can either be flexible or hard or tough.