Biochemistry: Carbon, Isomers, Lipids

SBI4U – Grade 12 AP Biology – Biochemistry Test Biochemistry Main Ideas Labs Enzymes Water Properties Property Chemical Reaction Biological Consequence Hydrogen Bonds (attractions) Cohesion Holds together water molecules together, helps the transport of water against gravity in plants Can travel through xylem from root to leaf Hydrogen Bonds ● Moderation of temperature ● Water absorbs heat from the wait and then releases heat into the cold air Sweat Can absorb/release a large amount of heat with only a slight change in its own temperature Hydrogen Bonds Expansion upon freezing A gap is created by the molecules' rearrangement. The molecules enlarge in size as a result. Ponds preserve fish/wild life Polar Covalent ● Versatility as a solvent ● All living things use water in one form or another to transport nutrients and etc Dissolubility Transportation ● Transporting; moving substances from one place to another Carbon Carbon Its properties include being able to make large molecules/chains because it is stable and has 4 possible bonds. – 1 bond ex. Ethane = 2 bonds ex. Ethene ≡ 3 bonds ex. Ethine Number of carbons in a molecule/chain 1. Methane 2. Ethane 3. Propane 4. Butane 5. Pentane 6. Hexane 7. Heptanes 8. Octane 9. Nonane 10. Decane Isomers Are compounds with the same molecular formal but different structures and properties Structural Isomers – Have different covalent arrangements of their atoms Geometric Isomers – Have the same covalent arrangements but different in spatial arrangements Enantiomer – Isomers that are mirror images of each other Functional groups ● – Are the components of organic molecules that are most commonly involved in chemical reactions ● – The number and arrangement of functional groups give each molecule it’s unique properties ● – Function groups give a carbonated chain certain properties, all compounds that have the same functional groups, share similar properties. Macromolecules Polymer – a long molecule consisting of mainly similar building blocks Monomers are small building block molecules All living things are made up four classes: Carbohydrates, Lipids, Proteins and Nucleic Acids all of them are polymers but lipids. Dehydration – when two monomers bond together through the loss of a water molecule (h2o) Hydrolysis – when water is used to break up two monomers Carbohydrates ● – includes sugars and polymers of sugars ● – the simplest carbohydrates are monosaccharides/single sugars ● – macromolecules are polysaccharides polymers composed of many sugar building blocks Disaccharides are formed when a dehydration reaction occurs and joins two monosaccharides This covalent bond is called a glycosidic linkage ––––––––– – Lipids are the one class of large biological molecules that do not form polymers unifying feature of all lipids is that has little or no affinity for water consists of fats, phospholipids and steroids Hydrophobic – because they are mostly made up of non-polar covalent bonds Fats- made up of two types of smaller molecules: glycerol and fatty acids Glycerol : 3 carbon alcohol with a hydroxyl group attached to each carbon Fatty Acid- consist of a carboxyl group attached to a carbon skeleton The length, number of carbons, and double- and triple-bond locations of fatty acids vary. Maximum hydrogen atoms are present in saturated fatty acids, which also don't have any double bonds. Example. lard, butter, and margarine Unsaturated fatty acids have double bonds throughout the carbon skeleton example. Oils Phospholipids – Are two fatty acids, a phosphate group that are attached to glycerol, the tails are a hydrophobic and the head is hydrophilic Steroids ● – Are lipids characterized by a carbon skeleton consisting of four fused rings ● – Example. Cholesterol important component in animal cell membranes ● – Testosterone and estrogen are also steroids Proteins There are many different types and functions for proteins Enzymes – accelerate reactions Ex. Digestive enzymes Structural – support Ex. Collagen Storage – storage of amino acids Ex. Ovalbumin in egg whites Transport- transportation of other substances Ex. Haemoglobin Hormonal – coordination of organisms activities Ex. Insulin Receptor – response of cell to chemical stimuli Ex. Nerve cells Contractile and Motor – movement Ex. Actin and myosin Defensive – protection against disease Ex. Antibodies (combat bacteria and viruses) Generic Formula for Protein (picture) Protein Structures Primary – Amino Acids join with peptide bonds and make a poly peptide. Ex. All proteins Secondary – folding of a polypeptide makes a β pleated sheet or α – helix. Ex keratin has a α- helix, collagen has β pleated sheets. Tertiary – folds into a 3D structure because of attractions between polar-polar bonds, acidbases and hydrogen bonds. Ex. Insulin Quaternary – when two or more tertiary structures join together. Ex. Haemoglobin Factors that affect Proteins pH – the acidic or basic parts of proteins are attracted to the solution Salt concentration – ions attract parts of molecules Temperature – nature of bonds are altered with dramatic temperature changes Enzymes Catalysts speed up the rate of a reaction lowers the energy required for a chemical reaction to happen; it is not a reactant so therefore remains unchanged at the end of the reaction Enzymes are biological catalysts that control chemical reactions that take places in the cytoplasm Ex. Catalase Enzymes are specific proteins which speed p reactions that are not used in the reaction and work best under optimum conditions Allosteric – shape of enzyme and substrate fit (lock and key) Inhibitors ● ● ● ● – Causes a loss of catalytic activity – Changes the proteins structure – May be competitive or non-competitive – Some of these effects are irreversible Competitive Inhibitors – They have similar structures to the substrate and competes with it for the active site, the effect can be reversed with an increase in the substrate concentration Non-competitive Inhibitors ● – Does not have a structure like the substrate but it binds to the enzyme, not necessarily the active site. ● – It changes the shape of the enzyme and active site, therefore no reaction occurs ● – The effect is irreversible and therefore the substrate cannot fit the altered active site which than leaves it inactive. DNA/Nucleic Acid The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a gene Genes are made of DNA, nucleic acid 1 gene: 1 protein DNA is like a recipe to create proteins and etc. There are two types of nucleic acids Deoxyribonucleic acid – DNA Ribonucleic acid – RNA Nucleic acids are polymers called polynucleotides Which are made of monomers called nucleotides Generic nucleotide (pic) Each nucleotide consists of a nitrogenous group, pentose sugar and a phosphate group. The portion without a phosphate group is called a nucleoside. The backbone of DNA is made up by phosphates Nitrogenous bases Pyrimidines – one cycle, Cytosine, thymine and uracil Purines -Double cycles, adenine and guanine A pyrimidine always bonds to a purine and vice and versa Hydrogen bonds which keep helix together