Biology



State of Illinois Goals for Science

State Goal 11: Understand the processes of scientific inquiry and technological design to investigate questions, conduct experiments, and solve problems.

State Goal 12: Understand the fundamental concepts, principles and interactions of the life, physical and earth/space sciences.

State Goal 13: Understand the relationships among science, technology, and society in historical and contemporary contexts


Biology Concepts and Supporting Ideas

Semester One will cover:

1. The Scientific Method and Safety.
2. Chemistry of Biological Processes.
3. Cellular Structures and Functions.
4. Energy Processes in Living Things.
5. DNA and Protein Synthesis.


Conceptual Statement 1: Chemistry of Biological Processes

Living things are made of elements that form biologically important molecules and compounds. Biochemical reactions involving these molecules and compounds form the basis of life processes within cells.

Supporting Ideas:

1. Through experimentation scientists have discovered that atoms, which are composed of protons, neutrons, and electrons, account for the different properties of the elements.

2. Several elements, such as carbon, hydrogen, nitrogen, oxygen, phosphorus, sodium, potassium, sulfur, calcium, and iron, form compounds that are necessary for life.

3. Covalent, ionic, and hydrogen bonds result from the underlying structure of elements. These bonds are formed or broken as molecules are assembled or rearranged during metabolism.

4. Water is essential to biochemical reactions because of its physical and chemical properties.

5. The chemical reactions of life require the maintenance of a narrow range of pH.

6. Experiments have shown that carbohydrates, proteins, lipids, and nucleic acids provide the raw materials for the structure and functions of life. These biological polymers are formed through dehydration synthesis.

7. Carbohydrates are composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio, which form monosaccharides, disaccharides, and polysaccharides. They are used to store energy and provide support.

8. Proteins, formed of amino acids linked together, comprise a chief building material fo organisms and also act as biological catalysts called enzymes.

9. Lipids are macromolecules that are insoluble in water. They store energy and are components of cell membranes.

10. Nucleic acids are long chains of nucleotides that contain the cell's hereditary information.

11. Metabolism includes all the chemical reactions involved in energy production, growth, reproduction, homeostasis, and communication.


Conceptual Statement 2: Cellular Structures and Functions

The cell is the basic unit of structure, function, and organization of all organisms. Certain cell types have organized structures within them called organelles. Each organelle has a specific function to perform in maintaining homeostasis. Our understanding of structure and function of the cell has been a direct result of advances in scientific technology.

Supporting ideas:

1. Cumulative historical observations using microscopes and conducting experiments have led to the development of the three principles comprising the cell theory: all living things are made up of cells, life processes occur in cells, and cells come from existing cells.

2. Cells can be classified as prokaryotes (which lack membrane-bound organelles) or eukaryotes (which have membrane-bound organelles).

3. Eukaryotic cells may have arisen from the joining together of more primitive cell types.

4. Advances in centrifugation and fractionation techniques have allowed scientists to determine the functions of individual organelles.

5. The nucleus of the living cell directs cellular activity and stores hereditary information.

6. Ribosomes, the sites of protein synthesis, are located on rough endoplasmic reticulum and are dispersed throughout the cytoplasm.

7. The endoplasmic reticulum is involved in the transport of proteins from the ribosome to the Golgi apparatus.

8. The Golgi apparatus packages and transports lipids and proteins for export or distribution throughout the cell.

9. The cell membrane, composed of proteins and phospholipids, separates the inside of the cell from its outside environment and as a semipermeable membrane, it regulates what enters and leaves the cell.

10. There are several ways in which substances are transported across cell membranes: diffusion (passive transport and osmosis), active transport, and facilitated transport.

11. Mitochondria and chloroplasts perform energy transformations in respiration and photosynthesis.

12. Cells in the body of multicellular organisms are arranged in structural and functional groups called tissues: tissues form organs and organs form organ systems.


Conceptual Statement 3: Energy Processes in Living Things

Energy is required to maintain life. All organisms have processes that utilize energy sources to maintain high levels of organization.

1. Organisms utilize a series of cyclic energy conversion reactions to meet their needs. Autotrophs convert energy from the sun or energy from inorganic compounds into energy-rich organic compounds. Heterotrophs obtain energy by consuming energy-rich organic compounds from other organisms.

2. Experiments have shown that chlorophyll and other pigments in autotrophs absorb light energy and are able to transfer the energy to complex organic reactions.

3. Photosynthesis in autotrophs includes a light-dependent stage in which energy is captured. Adenosine triphosphate (ATP) is generated, and free oxygen is released. In the light-independent stage (Calvin Cycle), the energy is used to make glucose from carbon dioxide.

4. In cells, ATP acts as an energy-transferring molecule that is repeatedly built up and broken down.

5. The products of photosynthesis provide the raw materials for cellular respiration and the products of cellular respiration provide the materials for photosynthesis.

6. During cellular respiration, all organisms obtain energy by breaking down the complex chemical compounds in foods and by synthesizing ATP molecules.

7. In the absence of oxygen, ATP can still be produced through glycolysis and fermentation.

8. Aerobic respiration produces more ATP for cell activity than does anaerobic respiration.


Conceptual Statement 4: Deoxyribonucleic Acid (DNA) and Protein Synthesis

Information stored in nucleic acids is passed from one generation to the next. This genetic information serves as the blueprint for making proteins, which are necessary for the operation of the cell.

Supporting ideas:

1. The discovery of the structure and function of DNA involved a variety of experimental techniques and has provided a framework for further study of cell reproduction and development.

2. X-ray crystallography has shown that DNA is a double stranded molecule, which consists of a series of paired nucleotides. Each nucleotide consists of deoxyribose, a phophate, and one of four nitrogen bases-adenine always pairs with thymine and cytosine always pairs with guanine.

3. The replication of DNA is facilitated by enzymes.

4. Ribonucleic acid (RNA) is a single stranded molecule, which consists of a series of linked nucleotides. Each nucleotide consists of a ribose, a phosphate, and one of four nitrogen bases-adenine, cytosine, guanine, and uracil.

5. Information stored within the DNA molecule can be copied into RNA molecules (transcription).

6. The RNA molecule directs the assembly of amino acids at a ribosome (translation) to form proteins. Amino acids are linked together through a dehydration synthesis reaction forming a peptide bond.

7. Changes in the information stored within the DNA molecule (mutation) may produce changes in proteins that can alter cell function or activity.

&nspa [Courses] Last update: November 3, 2000