proteins, carbs lipids

• Monosaccharides include glucose, fructose, galactose, ribose, deoxyribose, glyceraldehyde, and xylose.
• Disaccharides are formed by the condensation reaction between two monosaccharide molecules.
• Disaccharides include sucrose, lactose, maltose, trehalose, cellobiose, isomaltulose, palatinose, and melibiose.
• Sucrose is made up of one molecule of glucose and one molecule of fructose.
• Polysaccharides consist of many monosaccharide units joined together through glycosidic bonds.
• Starch is made up of amylopectin (branched) and amylose (unbranched).
• Glycogen is similar to starch but has more branches per unit length.
• Lipids are insoluble in water due to their hydrophobicity.
• the basic units of proteins are amino acids
• 1.What are the 3 major food groups? Carbohydrates, fats and proteins
• What are proteins made up of? Long chains of amino acids
• Monomers  are the smaller units from which larger complex  molecules are made.
• .

  Polymers are larger molecules made from joining lots of monomers together.
• •Go Go Mum!  

  Glucose + Glucose à Maltose
• •Go Father Son!

  Glucose + Fructose = Sucrose
• •Go Good Luck!

  glucose plus galactose = lactose
• Starch

  Chains of αlpha - glucose joined by condensation reactions- can be hydrolysed easily

  Starch is insoluble - doesn’t affect water potential-
• Cellulose

  •A polymer of β- glucose,•Long, unbranched chains
• Lipids are used for:

  1.Energy Source

  2. Waterproofing

  3. Insulation

  4. Protection
• 1.What are the components of a triglyceride?

  A molecule of glycerol and 3 fatty acids
• 1.Explain the difference between a saturated fatty acid and an unsaturated fatty acid

  A saturated fatty acid has NO C=C double bonds, an unsaturated one does contain C=C double bonds
• Give two reasons why triglycerides are used as energy storage molecules

  1.Because they contain lots of chemical energy (1) and are insoluble (1)
• 1.Explain how the structure of phospholipids make them able to form the bilayer of cell membranes

  1.Phospholipid heads are hydrophilic and their tails hydrophobic (1) so they form a double layer with their heads pointing outwards (1)
• dipeptides are formed by the condensation of 2 amino acids
• polypeptides are formed by the condensation of many amino acids
• Primary Structure-Number and order of amino acids in a chain
• Secondary structure-Hydrogen bonds form between amino acids in the chain causing it to coil into an alpha helix or fold into a beta pleated sheet.
• Tertiary structure-twisted and folded even more to give complex 3D shapes, this is called the polypeptides TERTIARY STRUCTURE. It gives the protein its unique 3D shape which is vital to its function
• Quaternary structure-Large proteins often contain more than one polypeptide chain.
• FIBROUS

  •Long chains which run parallel to each other

  •Chains are linked by cross bridges

  •Form stable molecules

  •Structural function
• GLOBULAR

  •More spherical

  •Carry out metabolic functions

  •E.g. enzymes/ haemoglobin/antibodies

  •Channel proteins in membranes
• •Enzymes are protein molecules which act as Biological catalysts.•They speed up reactions without being used up.•Each enzyme has a unique active site.•This is the place where the substrate binds to form an enzyme-substrate complex. Substrate is converted into product which then leaves the active site.
• Enzymes are affected by

  • temperature

  • pH

  • Substrate concentration

  • Enzyme concentration

  • Inhibitors
• 1.Carbohydrases- Break down carbohydrates, ultimately to monosaccharides.
• Amylase breaks down starch to maltose. Amylase is produced by the salivary glands and the pancreas
• Lipase enzymes catalyse the breakdown of lipids into monoglycerides and fatty acids. This involves the hydrolysis of the ester bonds in lipids.
• Proteins are digested by a combination of different peptidases. These are enzymes that catalyse the conversion of proteins into amino acids by hydrolysing the peptide bonds between the amino acids.