(2.2) Biological Molecules Flashcards
ONLY UP TO CARBOHYDRATES
Why is hydrogen bonding significant when it comes to water?
In isolation the bonds are weak however when there are many bonds between water molecules they’re strong
What is the molecular makeup of water?
H2O
How is water polar?
The oxygen is slightly negative and the hydrogen is slightly positive
How do water molecules bond together?
Hydrogen bonds
What are the properties of water?
- solvent
- cohesion
- adhesion
- surface tension
- solid is not as dense as liquid
- high specific heat
- high latent heat
- reactant
Why does water make a good solvent?
It’s polarity allows it to be attracted to and bond with negatively and positively charged molecules and ions
What is does it mean when water is cohesive?
The water molecules stick together well - due to hydrogen bonding
What does it mean that water is adhesive?
The water molecules stick to other things due to its polarity
What is an example of when water’s surface tension is important?
For pond skaters
Why is the fact that water is more dense as a liquid compared to a solid significant?
It means that when water becomes ice, the ice floats on the surface, insulating the water below making it good for habitats as temperature is maintained
What does high specific heat capacity mean?
It is hard to heat
Why is the fact that water has a high specific heat capacity significant?
The water is harder to heat so creates a good environment/habitat for animals
What is high latent heat?
It means it is hard to turn into a vapour
Why is the fact that water has high latent heat important?
It can be used as a cooling mechanism for many organisms e.g. sweat
Why is water a good reactant?
Water is used to form hydrolysis reactions and is removed during condensation reactions
What are carbohydrates?
Sugars
What are sugars?
Sweet, crystalline solids
What are hexose sugars?
Sugars with 6 carbons
What are pentose sugars?
Sugars with 5 carbons
What are triose sugars?
Sugars with 3 carbons
What is the molecular makeup of glucose?
C(6)H(12)O(6)
What are disaccharides?
Polymers of sugars
What is maltose made up of?
X2 Alpha glucose
What is sucrose made up of?
Glucose and Fructose
What is cellobiose made up of?
X2 Beta glucose
What is lactose made up of?
Beta Galactose and Alpha glucose
What are the three types of polysaccharides?
- Amylose
- Amylopectin
- Glycogen
Where is Amylose and Amylopectin found?
In Plants
Where is glycogen found?
In animals
What are Amylose, Amylopectin and glycogen?
Energy stores
What bonds are there in Amylose?
1-4 glycosidic bonds
What is the structure of Amylose?
Spiralled
What is amylose made up of?
Alpha glucose
What are amylose and amylopectin a component of?
Starch
Why is iodine effective when testing for starch?
Iodine fits within the coiled chain of amylose
What bonds are within Amylopectin?
1-4 and 1-6 glycosidic bonds
What happens when 1-6 glycosidic bonds are present?
The structure becomes branched
What is the benefit of 1-6 glycosidic bonds?
The branched structure means there are more ends for enzymes to bind to which means the energy store is more hydrolysable
What bonds are present in Glycogen?
1-4 and 1-6 glycosidic bonds
Why do Amylose, Amylopectin and Glycogen make good energy stores?
- compact
- non-soluble
- readily hydrolysable
Why is it beneficial that energy stores are non-soluble?
When they are stored in the cell they do not affect the water potential and mess with osmosis pathways
What sugar is glycogen made up of?
Alpha glucose
What is cellulose a polymer of?
Beta glucose
Why do beta glucose molecules flip when making up cellulose?
Due to the positioning of the hydroxyl groups
What is the structure of cellulose and why?
Cellulose chains are straight due to the constant rotation of carbon 6 (180 degrees)
What bonds are between cellulose chains and what does this do?
Hydrogen bonds which makes it stronger
What do cellulose chains bundle together to form?
Microfibrils
What do microfibrils bundle into?
Macrofibrils
What does the bundling of cellulose chains, microfibrils and macrofibrils create?
A strong but soluble cells wall
