Answer & Explanation:I need someone to reword everything on here so it wont be word for word. As most of this is from my book.Human BiologyCarbohydrates: the main unit of carbohydrates is a simple sugar or monomer made up of mostly carbon, hydrogen and oxygen which function mostly deals with energy as in how its stored and transport, and plant structure. Combined these molecules form sugars, starches, and cellulose.Lipids: are fats consisting of fatty acids attached to glycerol, Dietary fats are mostly triglycerides consisting of three fatty acids, which are attached to three carbons of glycerol.Nucleic Acids are either RNA and DNA, the molecules that store hereditary information and have the ability to process it. The basic unit is a nucleotide which includes a sugar, a phosphate and a purine or pyrimidine base.Proteins consist of chains of amino acids. They make up muscle bone and many structural elements of your bodies They help transport molecules, they regulate various functions most importantly as enzymes.-A condensation reaction is the forming of a water molecule and occurs when an enzyme removes a hydrogen atom from one sugar and an OH or hydroxyl functional group from the other sugar and join the two sugars together. Condensation reactions can produce proteins, polysaccharides, and triglycerides.Lipids act as a fuel reserve as well as provide structure and protection to a cells membrane. Lipids include fats, oils, waxes and cholesterol; they repel water and provide an energy source. They also have insulating properties, because they do not transmit heat well. If the structure of a lipid is altered it is not able to perform its functions, such as providing a protective coating to the cell membrane and the cell would be readily exposed to infections, and could also dissolve. Lipids are a very important part of the cell structure.Carbohydrates are primarily an energy source, to store energy and provide structure to molecules. Carbohydrates are formed from one or two monosaccharides that create a simple sugar and a chain of simple sugars compose complex carbohydrates. You can remove electrons from them, which are sources of energy. (They get passed down the electron transport chain and can be used to make ATP- the universal energy currency of the cell). Triglycerides have more removable electrons so they are the richest source of energy. Obviously a chain consisting of many individual sugars will have a lot more energy than just a simple sugar.Proteins: Made up of amino acids. In the R group of each aa is what makes it different and gives that aa its particular quality. The order of the amino acids in the polypeptide chain is what then also determines the secondary structure, how the protein will fold up and gives that protein its particular characteristics.Nucleic acids store genetic information and transmit that information from one generation to the next, and they also transmit information from one cell to the next during replication for cell use. Nucleic Acids are made up of 4 different bases. The order of the four nucleic acids along a linear DNA molecule is the code, 3 bases code for a particular amino acid. The structure as a double helix also allow for replication and transcribing. We will be learning more about this in the coming weeks. Some of you said that NA are an energy source. While it is true that one of the bases is ATP but a base is not a nucleic acid and so NAs are not generally regarded as energy sources.Lock and KeyThe enzyme is usually a protein that is used over and over again to speed up chemical reactions. It is not changed itself. Enzymes have at least one active site that causes a specific substrate to bind to it. This brings them in to contact with each other. They may slightly change their form and it lowers the energy of activation for a chemical reaction to take place. 2. Fluid Mosaic Model The membrane consists of a mosaic of protein molecules floating in a fluid bilayer of phospholipids. The lipid bilayer consists of two layers of phospholipids with the heads of the lipids outside and the tails of the lipids sandwiched inside the heads. Proteins are embedded within the lipid bilayer or attach to the bilayers outer or inner surface and can move around helping move particular substances in and out of the cell.Methods of TransportDiffusion The movement of a solute down a concentration gradient in relation to water, requires no energy Osmosis. The diffusion of water through a semi-permeable membrane and in a way is the opposite of diffusion since in relation to the solute it is moving to an area of higher solute concentration, not lower, but is considered a special form of diffusion.Facilitated Transport This also requires no energy, but makes use of transport proteins to help move molecules in and out of the cell.Active transport-a crucial aspect of active transport is that the cell needs to expend energy in the form of ATP to transport molecules that either are against a concentration gradient or to open up channels so that molecules can get through.Endocytosis and Exocytosis occurs to to move large molecules and particles through the cell that cannot just go through the membrane. In endocytosis a cell engulfs substances next to its surface. An indentation forms on the plasma membrane, and the substances are trapped in this indentation and pinches off to form a vesicle. The vesicle transports the substances into the cell. Exocytosis is the opposite. A vesicle full of substances moves to the cell surface and the membrane of the vesicle fuses with the cell membrane. The contents of the vesicle are then released to the outside of the cell. This also uses energy.
