2.2 bio molecules Flashcards
Explain the dipole covalent bonds found in water.
Unequal electron association results in a charge separation, so H is slightly positive and O is slightly negative.
Explain cohesion and adhesion in water.
Cohesion and adhesion occur due to the strong attraction between water molecules, so they are attracted more to the water than the surface.
Explain high specific heat capacity in water.
You need lots of energy to increase the temperature of 1kg by 1^c as they bonds are strong.
Name 3 types of carbohydrates.
monosaccharides, disaccharides, polysaccharides
What are the properties of monosaccharides?
Small, sweet, soluable. Energy sources.
What is the difference between alpha glucose and beta glucose?
The OH group is above carbon one in beta glucose.
How do you add two glucose units.
In a condensation reaction. Water is a product. It produces a 1-4 glycosidic bond.
What is two alpha glucose’s joined together?
Maltose.
What are the roles of polysaccharides?
Energy stores and structural.
What are the 4 main types of polysaccharides?
Amylose, amylopectin, cellulose and glycogen.
What is amylose?
Unbranched alpha glucose polymers found in the the mouth and the stomach. It spirals to make it smaller and is held together by hydrogen bonds.
What is amylopectin?
A branched form of glucose. It is more compact which is ideal for starch as it’s a store for glucose. Contains alpha 1-6 glycosidic bonds.
What is cellulose?
A polysaccharide made from beta glucose that has to alternate every other unit in order to form glycosidic bonds. It is extremely strong and is prevented from spiralling by multiple hydrogen bonds.
What is glycogen?
Glycogen is a branched polysaccharide made from alpha glucose. It contains 1-4 and 1-6 glycosidic bonds. It’s an energy store in humans.
How do you test for sugars?
Add 2cm of Benedicts solution to your solution. Heat for a few minutes. The darker red the precipitate, the more reducing sugars there are.
How can you adapt the benedicts test to test for non reducing sugars?
Add hydrochloric acid. Heat for 3 minutes and then cook. Neutralise with NaH2CO3, then preform the test as normal. This will hydrolyse the disaccharide into its constituent monosaccharides.
What are the types of lipids?
Triglycerides (saturated and unsaturated), phospholipids and cholesterol.
What are the roles of subcutaneous fat/blubber? (5)
Thermal protection, buoyancy, protection around the kidneys, energy storage in the fats in adipose cells and they make membranes and sex hormones.
What is the bond called between the glycerol and the fatty acids in a triglyceride?
Ester bonds.
What is a saturated fat?
This is where there are no double bonds, so all the carbons have maximum hydrogen attached. Found in meats and dairy. Solid at room temp.
What is an unsaturated fat?
They have double bonds, which form a kink. Found in seeds and oily fish. Liquid at room temp.
What are phospholipids?
Fats that contain a glycerol, two fatty acids and a phosphate group. They are amphipathic, so form micelles in water. Makes up 80% of membranes.
How do you test for proteins?
Add 2cm of bitter solution, and it will turn lilac if there are proteins present.
How do you test for lipids?
Add ethanol. Decant the liquid into a test tube of water, leaving any undissolved substances behind. If there are lipids dissolved in the ethanol, they will emulsify, forming a cloudy white emulsion.
