Module 2 - biological molecules Flashcards
What 3 elements are carbohydrates made from?
carbon, hydrogen and oxygen
What are carbohydrates
Carbohydrates are made up of single monomer units called monosaccharides
What are monosaccharides ?
single sugars
examples of monosaccharides
Hexoses
Glucose
Fructose
pentose
Ribose
Deoxyribose
What are disaccharides?
when 2 monomers join together
examples of disaccharides
Maltose
lactose
sucrose
What is maltose composed of?
two glucose molecules
What is a polysaccharide?
When many monosaccharides join
examples of polysaccharides?
Glycogen
Cellulose
Starch
What are oliosaccharides?
they have shorter - chain polysaccharide
- these are not sugars
Properties of monosaccharides
- single molecules
- sweet to taste
Do monosaccharides have glycosidic bonds?
No
Structure of monosaccharides
exist as a single ring shape
Solubility of monosaccharides in water
soluble
Roles of monosaccharides
- energy release, transported in blood
- monomers for other carbohydrates
Properties of disaccharides?
- two molecules covalently joined
- sweet to taste
Do disaccharides have glycosidic bonds?
single glycosidic bonds
Structure of disaccharides
two rings joined
Role of disaccharides
- energy release, storage, and transport within plants
Properties of polysaccharides
- many molecules covalently joined to each other
- not sweet
Solubility of polysaccharides in water?
insoluble
do polysaccharides have glycosidic bonds?
- many glycosidic bonds
structure of polysaccharides?
- long chains which may be branched and coiled
- compact
roles of polysaccharides?
-energy storage, structural component of the cell walls
Solubility of monosaccharides in water?
soluble
Two types of starch?
amylose and amylopectin
What is glucose?
Glucose in living organisms is a substrate used in aerobic respiration. This releases energy. It is small/soluble
Glucose formula
C6H12O6
what type of sugar is glucose?
Hexose sugar
Glucose exists in two forms:
alpha and beta
difference between alpha and glucose molecule
- same molecular formula, arranged differently.
- affects how moleules behave when they join to form polymers
what type of sugar are Ribose and deoxyribose
- Both pentose
C5H10O5
What is ribose used for?
Used in RNA
What is deoxyribose used for?
used in DNA
Features of disaccharides?
They form when a condensation reaction (loss of water) happens between 2 monosaccharides, forming 1-4 glycosidic bonds
How does maltose get breakdown into glucose?
- Hydrolysis reaction occurs
- addition of water
- and enzyme - maltose
Are all disaccharides reducing sugars?
Yes apart from sucrose
What roles does sucrose have in organisms?
Sugar is transported in the phloem of the plant
What role does lactose have in mammals?
- High in energy
- used in milk
what are polysaccharides?
large polymers which are made by joined by lots of monosaccharides together by condensation reactions, creating long chains
What bonds are monosaccharides joined by?
glycosidiacc bonds
Roles of polysacchardies?
Used as energy stores
- starch (plant cells)
- Glycogen (animal cells)
Structural strengths
- Cellulose (plant cell walls)
What is starch made from?
Starch is made from alpha glucose molecules arranged in 2 different ways; amylose and amylopectin
What is amylose?
long chains of 1,4, linked aplha glucose, coiled into a spiral shape
What bonds are amylose held by?
It is stabilised by hydrogen bonds holding the helix shape
What is amylopectin?
long chains 1,4 linked alpha glucose molecules with short branches (1,6 linked)
How is the structure of starch made as a good energy storage molecules in plants?
- unreactive - it is used as an energy store
- compact - a lot can be stored in a small space inside the cell due to amylopectin being branched and amylose being a helix
- energy is released for respiration
What is glycogen?
- main energy store in animals
- made of long chains of alpha glucose with 1-4 glycosidic bonds, highly branched (1-6 glycosidic bonds)
How is glycogen different to amylopectin?
- shorter chains
- more branches
- more compact
- can be stored into a small space
Why would animals need an energy storage molecule that is even more branched than found in plant cells?
-more branches means it is broken down more rapidly and release energy needed for cellular reactions
- animals are far more active than plants
where is cellulose found in plants?
cell walls
what is cellulose made from?
Beta glucose
Is cellulose a polysaccharide?
yes
How do beta glucose molecules join together?
They can join together if every other molecule is flipped 180 degrees
Structure of cellulose?
straight chain molecule
NOT coiled or branched
What bonds are formed between cellulose?
dellulose chains are linked by hydrogen bonds forming strong fibres called microfibrils
what are macrofibrils?
They are weak hydrogen bonds joined together to give them great strength
what happens to the macromolecules?
- they cross over each other to form the cell wall of plants
- they are embedded in a gel like structure called pectin which holds them into place
