Molecules for Biological Basis

Molecules for biological basis Proteins-Collagen Glucose Lipids-Phospholipids Carbohydrates- Nucleotides-ATP Learning Outcomes • • Identify the role that nucleic acids, carbohydrates, lipids, and proteins have as building blocks for cellular structures, cellular interactions and as signalling molecules. Recall that polymers are formed by dehydration reactions; monomers are recovered by hydrolysis of polymers Molecules of Life • Nucleic acids - • Nucleotides: we you have more than one nucleotide strong together. DNA RNA ATP, GTP (nucleoside triphosphates) (generally do not form polymers) Proteins Globular – enzymes, hormones (not all hormones are proteins) Fibrous – can be really strong things such as connective tissue, bone, hair Membrane – (membrane proteins sit within the plasma membrane and have a huge role in communication across that membrane) neuronal receptors, cell adhesion molecules Carbohydrates (one of the main sources of energy) Glucose (we store glucose as glycogen) Glycogen Lipids (some are able to store energy) Triglycerides - Phospholipids (form major constituents of the cell membrane) Fatty acids (component of both of the above two) Cholesterol - • • Organic vs. Inorganic • • Organic: molecules that contain carbon and hydrogen, bonded together. Inorganic: everything else that does not contain carbon and hydrogen. Monomers -> Polymers • • • • • • • Nucleotide -> DNA, RNA (nucleic acids) Amino acids -> polypeptides, proteins Monosaccharides -> polysaccharides, another word for this is carbohydrates Lipids are a bit different (not the same in terms of stringing together_ We take nucleotide (the monomer) and then they join together ad we get DNA and RNA. Monomers will string together to form a polymer. Monomers will be polymerised, where they will join together and for a polymer. • Monomers are polymerised to form a polymer. Dehydration Synthesis Dehydration synthesis – Removal of a water molecule between two reacting molecules forming a new covalent bond in the process. • • • • Each molecule has an OH at one end and an H at the other end. From one group OH is removed and from the other the hydrogen is removed. When making something and removing the water Those who have been removed they combine together to form water. Hydrolysis Hydrolysis – Addition of a water molecule to a polymer to break a bond within a polymer to form the monomers. • • • • • • • Using water to break things up Breaks the polymer into its monomers Want to break of the monomer at the end. Water is used and added to either ends. One gets hydroxyl and one gets hydrogen Dehydration reactions are known as condensation reactions Lysis means to break • Nucleic acids - DNA RNA ATP, GTP (nucleoside triphosphates Monomer – nucleotide (the monomer of nucleic acid) Nucleic acids – DNA • Nitrogen bases form hydrogen bonds between each other, which are strong, but not as strong as covalent bonds. It will polymerase with other n and it polymerises at the level of the phosphate group and the sugar. • • • This is a strong covalent bond The n bases from hydrogen bonds between each other. (GCAT) Hydrogen bonds are strong but not as strong as covalent bonds. ATP & GTP • • ATP sometimes called the energy “currency” of the cell ATP is very similar to the n in the DNA it has ribose sugar, adenine nitrogenous base and a triphosphate group. - • Generated in the mitochondria Important for: ✓ Muscle contraction ✓ Maintenance of membrane potential: when we want to keep the membrane potential inside the cell different from the membrane potential outside the cell. This takes up an enormous amount of energy. ✓ Assembly of complex molecules ✓ Cellular transport ✓ etc. GTP - Same structure as ATP, but instead of A, G. Signal transduction within the cell Synthesis of RNA and DNA Protein synthesis Gluconeogenesis ATP and GTP • • • • • • They are useful because of the phosphate Because the more energy as phosphate groups are added, because it takes lots of energy to added it. Mitochondria will take energy from glucose for example and use that energy and put a phosphate on the ATP. ATP able to donate its phosphate, and when donated this energy does not go anywhere itcan released. It is a way of having loads of energy in a bond in a small molecule that can travel anywhere. The more phosphates there is, the more energy required to add additional phosphates. Energy s taken from the mitochondria to add additional phosphates. Nucleic acids – DNA Nucleic acids – RNA Uracil takes the place of thymine – pairs with adenine during transcription. • Transcription where we are copying of a gene on the DNA into mRNA. Nucleic acids – structure • • • DNA molecules form a double helix. - Also forms tertiary structures – chromatin. - Hydrogen bonds between nitrogenous bases. RNA molecules are single stranded. Just forms a helix it is not paired up - They do not pair up in the same way as the DNA - Can form many different structures. - Tertiary structure, where it folds up into something useful. Proteins - Globular – enzymes, hormones Fibrous – connective tissue, bone, hair Membrane – neuronal receptors, cell adhesion molecules Protein Monomer – amino acid • Amino acid is the monomer of the protein • Has three parts to it • • • • • • • R just denotes a different side chain, which can be any of 20 different types of side chains. R=random R is a variable Amino acid monomers link to form polypeptides via dehydration synthesis type of reaction. Peptides is used for really short strings of amino acids. Peptide bonds Typically, “peptides” are 2-50 amino acids, proteins are > 50 amino acids. Additionally, proteins will have tertiary and/or quaternary structures. Amino Acids 20 types directly coded for by the genetic code. • • • • • Amino acid monomers link to form polypeptides via dehydration synthesis. The way amino acids bond together is what we call, between the c terminus (carboxylic acid side of the molecule) and n terminus. Once they join together one end of the string is going to be the c terminus and one end is going to be the n terminus. So, we get this peptide bond forming via ds between carbon and nitrogen. Peptide for really shot strands of amino acids Proteins have more structures than just strings of amino acids.