Assignment: Biological Macromolecules
Assignment: Biological Macromolecules
This experiment requires your lab kit.
You will explore the basic properties of the chemistry that underlies biology. You will determine the presence of biological macromolecules such as proteins and carbohydrates using reagents that change color in their presence.
Additional Materials needed for the labs (not included in lab kit)
Experiment 1: egg white, potato, onion, hot water, fork, knife, hot water bath, tap water
Photos of the results of all the tests in this experiment are required. Please include within the pictures an index card with your name and date.
We discussed last week that the properties of living organisms are determined by the properties of their building blocks. These building blocks interact through chemical bonding, and then form even larger entities. The elements most frequently found in biological molecules include carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, and a few others in smaller amounts. The chemistry of the element carbon is particularly important for the formation of “organic molecules” that form the basic structure of biological molecules.
Biological molecules can be very large in comparison to atoms or subatomic molecules and are referred to as biological macromolecules (macro means “big”). Learning about macromolecules is important to understanding living organisms. All living organisms are characterized by the presence of four major classes of macromolecules: proteins, carbohydrates, lipids, and nucleic acids. These macromolecules are often called the molecules of life.
Biological macromolecules such as proteins are able to carry out specific functions in living organisms. For example, certain proteins such as enzymes act as catalysts—substances that increase the rate of a chemical reaction between other molecules but do not change chemically themselves. These enzymes activate reactions occurring within living organisms.
However, enzymes and other biological molecules made of matter do not possess the properties of life. Only after we combine these molecular building blocks to form a cell can we finally see the emergent property of life. At this point we have the smallest units of structure and function in biology: cells are then living entities.
Types of cells differ considerably in their structure, size, shape, and function. Scientists usually categorize cells based on their structural features. You will learn these classifications and understand how those different features affect the cell’s purpose and abilities. Some living organisms, including humans, are composed of many different cell types among trillions of cells. Other living organisms, such as bacteria, are composed of just one single cell.
In this section, we will discuss cell theory and the various organelles of a cell. We will then learn about a cell structure called the plasma membrane and see how materials move in and out of this membrane.
You will also complete a laboratory experiment related to biological macromolecules.
And you will demonstrate your knowledge of course concepts with a quiz.
Week 2 Outcomes
By the end of this week, you should be able to
- describe the structure and function of biological molecules;
- explain cell theory, the role of cells, and methods of studying cell structure;
- compare and contrast eukaryotic and prokaryotic cells;
- compare and contrast animal and plant cells;
- describe the structure and functions of the major cell organelles, as well as the cytoskeleton and extracellular matrix;
- explain the fluid mosaic model of membranes and the processes of cellular transport in eukaryotic cells;
- determine the presence of proteins, glucose, starch (carbohydrate) using indicator solutions;
- manipulate test tubes and measure liquids;
- measure pH (acidity) using pH strips; and
- apply concepts and/or argue a position related to a scientific topic.