Biological Molecules Flashcards
What is a monomer?
One of many small molecules that combine to form a larger one known as polymer
What is a polymer?
Long chains of monomers.
What is a monosaccharide?
Sweet tasting, soluble substances that have the general formula (CH2O)n.
What is the test for reducing sugars?
Add Benedict’s reagent and heat.
It should turn from blue to brick red.
What is a disaccharide?
pairs of monosaccharides can be combined.
What do to glucose molecules form?
Maltose
When glucose joins to fructose, what is formed?
Sucrose
When glucose is joined to galactose, what is formed?
Lactose
When monosaccharides join, what kind of reaction is it?
It is a condensation reaction because a water molecule is removed and the bond that is formed is glycosidic
What bond is formed between carbohydrates?
A glycosidic bond is formed.
When a water molecule is added to a disaccharide, what reaction is this?
Hydrolysis reaction
What is a polysaccharide?
Polymers, by combining together many monosaccharides.
What is the test for starch?
Add potassium iodide solution at room temperature.
The solution should go from yellow to blue-black if starch is present.
What is starch?
A polysaccharide that is found in many part of a plant in the form of small grains.
What type of glucose is found in starch?
Starch is made up of chains of alpha glucose monosaccharides linked by glycosidic bonds that are formed by condensation reactions.
What is the main role of starch?
The main role of starch is energy storage.
What makes starch effective at storing energy?
It’s insoluble so doesn’t affect water potential, so water isn’t draw. In by osmosis.
Large
Compact, so a lot can be stored in a small space.
When hydrolysed it form alpha glucose, which is both easily transported and readily used in respiration.
Where is glycogen found?
Glycogen is found in animals and bacteria but never in plant cells.
What makes glycogen different to starch?
Shorter chains and highly branched.
Where is glycogen stored usually?
Glycogen is usually stored in muscled and the liver.
What makes glycogen effective for storage?
- Insoluble
- Compact
- Highly branched so has a lot of ends that can be acted on simultaneously by enzymes
What type of glucose is cellulose different to starch and glycogen?
It is made of monomers of beta glucose rather than alpha glucose.
Describe the structure of cellulose.
Straight unbranched chains that run parallel to one another, allowing hydrogen bonds to form cross linkages between adjacent chains.
Where is cellulose found?
In the cell wall
What are the main groups of lipids?
Triglycerides and phospholipids.
Are lipids soluble?
Not in water but they are soluble in alcohols and acetone.
What are the main roles of lipids?
- Contribute to the flexibility of the cell membrane and help the transfer of lipid soluble substances across them.
- source of energy
- waterproofing
- insulation
- protection
