Biological molecules- carbohydrates Flashcards
Define a condensation reaction
Joining of monomers via chemical bonds and the removal of water
Define a hydrolysis reaction
Addition of water in order to break a chemical bond between 2 molecules
What is the monomer of a carbohydrate, and give an example
Monosaccharide
Glucose
What is the polymer of a carbohydrate, and give an example
Polysaccharide
Starch
Give the 3 components of a carbohydrate molecule
carbon
hydrogen
oxygen
How does an beta glucose molecule differ from an alpha glucose molecule
In beta glucose, the OH group is above the plane of the ring where in alpha it is below
State 3 uses of carbohydrates
substrate for respiration
energy store
structural support
Monosaccharides have a carbon backbone, what does this mean
one carbon forms a double bond with an oxygen, other carbons are bonded to hydrogen and a hydroxyl group
What is isomerism
Glucose taking a differing structure
how many carbon atoms does glucose contain?
6 carbons
Give the definition of a disaccharide
2 monomers joined together by a 1-4 glycosidic bond
Glucose + Glucose=
Maltose
Glucose +——- = lactose
glactose
Glucose + fructose =
sucrose
What are polysaccharides
Many glucose units joined together
Which type of glucose to these complex carbohydrates contain?
glycogen
starch
cellulose
Gylcogen= alpha
starch = alpha
Cellulose = beta
Give the composition of a glycogen molecule
Many alpha glucose molecules joined both
small 1-4 and 1-6 gylcosidic bond giving less tendancy to coil
Glycogen molecules have BRANCHES , why is this important
Allows for the quick release of energy in animals due to having more enzyme-connecting endings
Why is glycogen a good storage molecule
It is a large but compact molecule
State the 2 polysaccharides present in a starch molecule
amylose
amylopectin
What is amylose?
Long UNbranched chain of alpha glucose, joined by 1-4 glycosidic bonds ONLY
Give the structure of amylose
coiled and compact for efficient energy storage
What is amylopectin
Long ,BRANCHED chain of alpha glucose joined by BOTH 1-4 and 1-6 glycosidic bonds
Why does amylopectin supply quick energy release
Amylopectin has branches which allow it to be rapidly digested by enzymes which easily break down the glycosidic bonds
What is cellulose
Long straight UN branched chains of Beta glucose
How are cellulose molecules joined
Strong hydrogen bonds which form microfibrils
Why is cellulose difficult to digest
microfibrils are embedded into a framework of hemicellulose and pectins which provide strength and support
Why is each alternate glucose molecule in cellulose rotated 180 degrees
To allow the bonding of hydroxyl groups, so that the alcohol group of alternate molecules is ABOVE the plane of the carbon ring
Cellulose can be stretched and can withstand high levels of turgid pressure, what is this definition
High tensile strength
How are cellulose fibres freely permeable
Space between the fibrils allow water and mineral ions to pass through
What is the significance of starch being and insoluble molecule
It has no osmotic effect
Where is there a high concerntration of glycogen molecules
In liver and muscle ceels
