1.1 carbohydrates and 1.2 lipids

define monosaccharides and name the three hexose monosaccharides

organic monomer that cannot be hydrolyzed to a simpler sugar

hexose: glucose, fructose, galactose

structure of alpha and beta glucose

alpha: down up down down

beta: down up down up

relate the structure of glucose to its functions

1. small and water soluble: easily transported

compare the structure of a disaccharide with glycogen

similarities:

1. both contain C,H,O

2. both contain glycosidic bonds

3. both contain glucose

differences:

1. glycogen contains 1,4 and 1,6 glycosidic bonds whereas disaccharides only contain 1,4

2. glycogen only contains glucose where as disaccharides contain glucose and other monosaccharides

structure of ribose and deoxyribose

ribose: pentose, monosaccharide

deoxyribose: hexose, monosaccharide

condensation and hydrolysis

condensation: chemical bond forms between 2 molecules and a molecule of water is produced

hydrolysis: water molecule is used to break a chemical bond between 2 molecules

what type of bond forms when monosaccharides from?

• glycosidic bond

2 monomers: disaccharide

2 or more monomers: polysaccharides

3 disaccharides and how they form

sucrose: fructose and glucose

maltose: glucose and glucose

lactose: galactose and glucose

polysaccharide and 3 examples

made from repeating monosaccharide unit:

• starch

• glycogen

• cellulose

structure and function of starch

storage polymer in plant cells ( they are large and insoluble ) → prevents affecting osmosis

compare amylose and amylopectin

amylose:

• 1,4 glycosidic bond

• straight chain

• unbranched

• compact

amylopectin:

• 1,4 and 1,6 glycosidic bond

• branched (rapid hydrolysis can happen to release glucose)

similarities:

• both contain alpha glucose

• both contain glycosidic bond

structure and function of glycogen

main storage polymer in animal cells

• 1,4 and 1,6 glycosic bond

• branched

• insoluble

• compact

structure and function of cellulose

polymer that gives rigidity to plant cell walls

• 1,4 glycosidic bonds

• straight chain

• unbranched

• high tensile strength

• many hydrogen bonds hold molecules together to prevent cell lysis

• polar nature of glucose allows water to diffuse through

triglycerides formation

condesnation reaction between 1 molecule of glycerol and 3 fatty acids to form ester bonds

compare saturated and unsaturated fatty acids

saturated:

• contains only single bonds

• straight chain molecules

• high melting point (solid)

• found in animal fats

unsaturated:

• contain C=C double bonds

• ‘kinked’ spread wider apart

• lower melting point (liquid) → weaker intermolecular forces

• found in plant oils

structure and function of phospholipids

glycerol backbone attached to hydrophobic fatty acid tail and hydrophilic polar phosphate head

• phospholipid bilayer in water that is a component of cell membranes

• waterproofing

polysaccharides formation

• glycogen and starch formed by condensation of alpha glucose

• cellulose formed by condensation of beta glucose

test for reducing and non reducing sugars

1. add benedicts solution to test for reducing sugars and heat

2. compare next to chart for the colour change to see concentration

3. add HCL into the non reducing sugar solution and heat

4. this neutralises the HCl (making the non reducing sugar solution neutral or alkali

5. then add the same volume and concentration of benedict’s test and compare next to chart to see colour change and concentration

devise and experiment to confirm the relative sweetness of sugars

• same concentration of sugar used

• tested by same person

• sweetness compared to sucrose

• water or buscuit in between tasting

compare glucose and fructose

similarities:

• both are hexose

• both contain covalent bonds (basically the glycosidic bond)

differences:

• glucose is hexagon fructose is pentagon

• glucose has one CH2Oh and fructose has two

advantages of having fructose in seminal fluid

• source of energy for sperm

• because movement requires ATP

• in order to reduce competition

why lipids are used as energy storage and insulation

• non polar

• insoluble

• don’t conduct heat because loosely packed large molecules

method to see if length of fatty acid chaings and degree of saturation affect melting point

• heat solid samples and measure temp at which they melt

• use fatty acids of the same chain length but with different C=C double bonds

• use fatty acid of different chain length but same number of single bonds

• repeat and calculate mean

properties of lipoproteins that enable cholesterol and fatty acids to be transported in blood

• cholesterol are hydrophobic

• phospholipids tails are hydrophobic so they can be carried inside the lipoprotein

• lipoprotein are hydrophilic so they can transport in the bloodstream

why glycogen releases energy more slowly than glucose

• glycogen is a polymer

• so glycosidic bonds need to be broken

why are triglycerides a good energy store

• carbohydrates and proteins are hydrophillic

• triglycerides are hydrophobic

• therefore the water will want to associate with proteins and carbohydrates but would be repelled by triglycerides