Biological molecules Flashcards
What are the main elements found in carbohydrates?
Carbon
Hydrogen
Oxygen
What is a monomer?
Individual molecules that make up a chain
What is a polymer?
A long molecule made up of repeating smaller molecules, monomers, joined up together
What is the name for a sugar monomer?
Saccharide or monosaccharide
What is the name for 2 monosaccharides joined together?
Disaccharide
What is the name for many saccharides joined together?
Polysaccharide
What is the difference between alpha and beta glucose?
Alpha - hydroxyl group above
Beta- hydroxyl group below
What is the test for reducing sugars?
Blue Benedict’s solution turns brick red on heating
What is a condensation reaction?
When monomers are joined together
What is always made during a condensation reaction?
Water
what type of reaction breaks down polymers into their monomers?
Hydrolysis
Name 2 polysaccharides that make up starch
Amylose
Amylopectin
What type of glucose makes starch?
Alpha
Describe the shape of amylose molecules
Unbranched alpha glucose chain
Coiled
Compact
Describe the shape of amylopectin molecules
Long branched alpha glucose
Explain which molecule, amylose or amylopectin, can be broken down quickly to release glucose
Amylopectin, because its side branches let enzymes get to the glycosidic bonds quickly
Why is it useful for starch to be insoluble in water?
Does not cause water to enter cells by osmosis - so can be used for storage without cells swelling up with water. It doesn’t affect the water potential.
What type of glucose makes glycogen?
Alpha
Describe the shape of glycogen molecules
Long
Very branched alpha glucose
What makes glycogen a good storage molecule?
Lots of branches so glucose can be released off it quickly
Very compact
What type of glucose makes up cellulose?
Beta
Describe the structure of cellulose
Long unbranched chains
Linked together by hydrogen bonds
To make strong microfibrils
What is the test for starch?
Brown iodine solution turns blue/black
Iodine solution is dissolved in potassium iodide solution
What are the 3 elements in lipids?
Carbon
Hydrogen
Oxygen
Are lipids soluble in water?
No
What do lipids dissolve in?
Alcohol/ acetone
What is the difference between an oil and a fat?
Fats are solid at room temperature
Oils are liquid at room temperature
What is a triglyceride?
3 fatty acids linked to 1 glycerol
What type of reaction joins the fatty acid to glycerol?
Condensation
What type of reaction would separate the fatty acid from glycerol?
Hydrolysis
What enzyme hydrolyses lipids?
Lipase
What is a saturated fatty acid?
Single C-C bonds only
What is an unsaturated fatty acid?
Double C=C bonds
How do unsaturated bonds affect the structure of lipids?
Make the molecules bend
So cannot pack closely together
So are solids at room temperature
What are the products when glycerol reacts with 3 fatty acids?
Triglyceride + 3 water molecules