B1.1 Carbohydrates And Lipids Flashcards
Why is carbon so structurally important in biological molecules?
- Carbon atoms has unique properties that allow it to form up to 4 covalent bonds.
- It can bond with itself to form strong substances like diamond and graphite.
- Can form many different shapes.
What is an organic molecule?
Organic refers to molecules containing carbon and hydrogen, such as CH4 and C6H12O6.
What is an inorganic molecule?
Inorganic refers to molecules with carbon and hydrogen (both can’t be present with each other). Examples are CO2 and H2O.
What are the functional groups?
Hydroxyl -OH
Carboxyl - C is double bonded to O and single bonded to OH group
Amine N attached to 2H
Phosphate bonded to 4 O
Must know all of these
What is a hydrocarbon?
Combination of C & H
Glucose
Exists as alpha and beta glucose
Structural isomer
Are molecules that have the same molecular formula but have a different arrangement of the atoms in space.
Fructose
Formed in plants, very sweet. Used to sweeten fruits to lure animals to eat the fruit to disperse seeds. Also the main sugar in honey.
Galactose
Combines with glucose to form lactose, the disaccharide found in mammal milk.
Condensation reaction
Where water is formed
What are polysaccharides?
Are polymers containing many monosaccharides linked by glycosidic bonds. Like disaccharides, polysaccharides are formed by condensation reactions.
Mainly used as an energy store and as a structural component in cells.
Examples are starch and cellulose as well as glycogen.
What are the functions of cellulose, starch and glycogen
Starch - storage form of carbohydrates in plants.
Glycogen - storage form of carbohydrates in humans and other vertebrates.
Cellulose - cell wall mostly made of cellulose as it provides structural support.
What are lipids?
Composed of hydrogen and carbon atoms.
They are non polar
Lipids are therefore hydrophobic and water insoluble
What are the four types of lipids?
Steroids
Triglycerides
Waxes
Phospholipids
Function of triglycerides
Used for long term energy storage
Role of lipids
Their main role is to be an energy source as they provide more than twice the energy in comparison to carbohydrates.
Lipids are also stored in adipose tissue which has several important roles including:
Heat insulation: adipose tissue helps reduce heat loss.
Protection: adipose tissue around delicate organs such as the kidneys and acts as a cushion against impacts.
Carbohydrates vs lipids
Storage - lipids has a long term energy storage. Opposite for carbohydrates.
Osmolality - lipids have less of an effect osmotic pressure. Carbohydrates have more effect.
Less easily digested - can only be used for aerobic respiration. While carbohydrates can be used for aerobic and anaerobic respiration.
ATP yield - lipids store twice as much ATP per gram than carbohydrates.
Solubility - lipids aren’t water soluble meaning they are harder to transport while carbohydrates are.
Saturated vs unsaturated
Saturated - all single c-c bonds
Unsaturated - at least one c=c bond
Poly unsaturated - many double bonds
As chain length increases why does melting point increase?
The longer the chain, the more bonds needed to be broken.
Unsaturated fatty acids can be either:
Cis-unsaturated:
Naturally occurring
Causes a kink in the fatty acid chain
Hydrogen atoms are on the same side of the c=c bond.
Trans-unsaturated:
Are not found in nature and are the result of human food processing such as butter.
Hydrogen atoms are on opposite sides of the c=c bond.
Causes a straighter fatty acid chain.
