1.3: Biological Molecules Flashcards
what Elements are carbohydrates made from?
Carbon, Hydrogen and Oxygen
What is the general formula for carbohydrates?
Cx(H20)y
what are Polymers?
Monomers joined together in a polymerisation reaction
what are monomers of carbohydrates called
Monosaccharides
Two Monosaccharides joined together form..
Disaccharides
Many Monosaccharides joined together are called…
Polysaccharides
Monosaccharides general formula
(CH20)n
N could be from 3 - 7
Characteristics of Monosaccharides
- Sweet tasting
- Highly soluble in water
Glucose (Monosaccharides) formula
C6H12O6 (Hexose sugar)
What are isomers?
One of two or more compounds that have the same chemical formula but different arrangements of the atoms. Same chemical formula but different ring structures
What are the isomers glucose forms?
Alpha glucose
Beta Glucose
What are the 2 main roles of monosaccharides?
- Source of energy during respiration (due to C-H bonds releasing lots of energy when broken)
- Important building blocks for larger molecules E.G. glucose is used to make starch
What reaction forms disaccharides?
Condensation Reactions
What bond and other properties are formed in a condensation reaction?
- Glycosidic bond
- Water
Rules for drawing condensation reactions
- always circle the groups
- always show that water is released
- always circle & label the bond that is formed
What is the opposite reaction to a condensation reaction?
Hydrolisis
What are polysaccharides?
Polysaccharides are polymers made of many monosaccharides joined together by glycosidic bonds (condensation reactions)
Properties of polysaccharides
- Not sugar/sweet tasting
- soluble in water
Starch
- where is it found?
- what are the monomers?
- plants ONLY
- Alpha glucose
Glycogen
- where is it found?
- what are the monomers?
- Animals & fungi
- alpha glucose
Cellulose
- where is it found?
- what are the monomers?
- Plants ONLY
- Beta Glucose
why do organisms use polysaccharides as an energy store instead of glucose?
- glucose is soluble in water
- accumulation of glucose in the cell would lower the water potential of the cell
What is the main role of starch?
Energy store - stored as granules in chloroplasts, seeds and storage organs (e.g. potatoes)
what is starch made up of? (with percentages)
Amylose (20%)
Amylopectin (80%)