Please enable JavaScript.
Coggle requires JavaScript to display documents.
Biological Molecules 1.1-2.2, sucrose - fructose and glucose lactose -…
Biological Molecules 1.1-2.2
Carbohydrates and Monosaccharides
Most carbs are polymers (a long complex chain on monomers)
examples of monomers - amino acids, nucleotides and monosaccharides
Carbs are made from monosaccharides
examples of monosaccharides - glucose, fructose, galactose
Two types of glucose - alpha and beta
Condensation reactions join monosaccharides together to form disaccharides. This reaction forms a glycosidic bond between two molecules and leaves a water molecule behind.
Polymers are broken down by hydrolysis reaction - it is done by the addition of a water molecule
Starch
Mixture of two polysaccharides of a-glucose
-amylopectin
-amylose
amylopectin - branched, the branches allow it to break down the glycosidic bonds quickly which allows for a quick release of energy
amylose - unbranched and coiled to make it more compact, a small storage but a large capacity
Starch is insoluble in water which means it doesn't affect the water potential, means the cells don't swell, making it even better for storage
Glycogen
Excess glucose storage for animals
Polysaccharide of a-glucose
Lots of side branches to allow for quick release of energy + very compact molecules which is good for storage
Cellulose
Long unbranched b-glucose
straight cellulose chains held together by hydrogen bonds which form microfibrils, this means it can provide structural support for the cell
Lipids
Triglycerides
3 fatty acid tales made of hydrocarbons and a glycerol head
Insoluble in water due to the hydrophobic tails
formed by a condensation reaction and join to a glycerol molecule
Fatty acids can be saturated or unsaturated
saturated = single bond between carbon atoms
unsaturated = double bond between carbon atoms
Lots of energy is released when they are broken down
Phospholipids
2 fatty acid tails and a phosphate group, still with a glycerol molecule
Hydrophilic head and hydrophobic tail
creates the cell membrane bilayer - the centre is hydrophobic which means water soluble molecules can't pass through it easily
Proteins
Proteins are made up of two or more chains of amino acids
There are 20 types of amino acids
Primary Structure
A polypeptide chain of amino acids
Secondary Structure
The chain either begins to coil into an alpha helix shape or begins to fold into a beta plated sheet with hydrogen bonds
Tertiary Structure
The coil is either coiled further or the sheet is folded further. Bonds now include disulphide bridges, hydrogen and ionic bonds. Creates a 3D structure
Quaternary Structure
Two or more polypeptide chains held together by bonds. 3D structure
A dipeptide is formed when two amino acids join together via a peptide bond between the carboxyl group of one amino acid and the amine group of another
Enzymes
Lock and key model
Complimentary substrate to fit an active site
Induced-fit model
The substrate makes the active site change shape to fit the shape of the substrate
Enzymes have tertiary structures, if the structure is changed by something like temperature or PH, then it can no longer bind to the active site
DNA and RNA structure
The pentose sugar in DNA is called deoxyribose and in RNA is called ribose
4 possible bases in DNA - A (adenine), T(thymine), C(cytosine), G(guanine) (in RNA U - uracil - replaces T)
Polynucleotide is a polymer of nucleotides formed during a condensation reaction between the phosphate group of one NT and the sugar of another. This creates the sugar-phosphate backbone with phosphodiester bonds
DNA is made from two polynucleotide strands joined together by hydrogen bonds between the bases which have complimentary base pairs (A-T {two H bonds}, C-G {three H bonds})
twist to form a double helix (Watson and Crick)
sucrose - fructose and glucose
lactose - glucose and galactose
maltose - glucose and glucose
