Thursday, December 7, 2017

Macromolecules

Please do the following things to understand more about macromolecules:

1) Read this information from Khan Academy on Macromolecules


Introduction
Think back to what you ate for lunch. Did any of your lunch items have a “Nutrition Facts” label on the back of them? If so, and if you had a look at the food's protein, carbohydrate, or fat content, you may already be familiar with several types of large biological molecules we’ll discuss here. If you’re wondering what something as weird-sounding as a “large biological molecule” is doing in your food, the answer is that it’s providing you with the building blocks you need to maintain your body – because your body is also made of large biological molecules!
Just as you can be thought of as an assortment of atoms or a walking, talking bag of water, you can also be viewed as a collection of four major types of large biological molecules: carbohydrates (such as sugars), lipids (such as fats), proteins, and nucleic acids (such as DNA and RNA). That’s not to say that these are the only molecules in your body, but rather, that your most important large molecules can be divided into these groups. Together, the four groups of large biological molecules make up the majority of the dry weight of a cell. (Water, a small molecule, makes up the majority of the wet weight).
Large biological molecules perform a wide range of jobs in an organism. Some carbohydrates store fuel for future energy needs, and some lipids are key structural components of cell membranes. Nucleic acids store and transfer hereditary information, much of which provides instructions for making proteins. Proteins themselves have perhaps the broadest range of functions: some provide structural support, but many are like little machines that carry out specific jobs in a cell, such as catalyzing metabolic reactions or receiving and transmitting signals.
We’ll look in greater detail at carbohydrates, lipids, nucleic acids, and proteins a few articles down the road. Here, we’ll look a bit more at the key chemical reactions that build up and break down these molecules.
Monomers and polymers
Most large biological molecules are polymers, long chains made up of repeating molecular subunits, or building blocks, called monomers. If you think of a monomer as being like a bead, then you can think of a polymer as being like a necklace, a series of beads strung together.
Carbohydrates, nucleic acids, and proteins are often found as long polymers in nature. Because of their polymeric nature and their large (sometimes huge!) size, they are classified as macromolecules, big (macro-) molecules made through the joining of smaller subunits. Lipids are not usually polymers and are smaller than the other three, so they are not considered macromolecules by some sourcesstart superscript, 1, comma, 2, end superscript. However, many other sources use the term “macromolecule” more loosely, as a general name for the four types of large biological moleculesstart superscript, 3, comma, 4, end superscript. This is just a naming difference, so don’t get too hung up on it. Just remember that lipids are one of the four main types of large biological molecules, but that they don’t generally form polymer
s.

Friday, November 17, 2017

Photosynthesis and Cellular Respiration Extension

Here is a document that will help introduce the next topic that we are going to cover: Cellular Respiration

Photosynthesis and Cellular Respiration