Anatomy & Physiology
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. In this unit we learned about the human body in depth with units such as the skeletal system, muscular system, and internal organs and functions such as the exretory system, digestive system, circulatory system, and respiratory system.
Evolution
Our next unit in bio was a unit on evolution. Evolution is the change across any successive generations in the inherited characteristics of biological populations. In this unit we learned about fossils and gradual changes in species along with the theory of darwinism.
Science Fair
Our next assignment in Biology was the science fair. We had been working on it slowly, all year, but we had to really push hard in the last few weeks before the science fair. Sarah Hargraves and I were in a group. We did the project on bacteria growth on the tops of soda cans. We used petri dishes and incubators to grow bacteria, collected our data, made a research report and trifold and entered it into the science fair. We did not place in the fair, but we got a 95 on the project in class and I was happy with our results.
Mid Year Exam
We had a large test on what we have learned from the beginning of the year to now. This test will be really hard because it is a lot of material and we also have science fair going on at the same time.
Cellular Respiration
Cellular respiration is the process by which the chemical energy of "food" molecules is released and partially captured in the form of ATP. Carbohydrates, fats, and proteins can all be used as fuels in cellular respiration, but glucose is most commonly used as an example to examine the reactions and pathways involved. Cellular respiration is split into 3 groups: Glycolysis, The Krebs Cycle, and Oxidative Phosphorylation. Glycolysis occurs in the cytosol, while The Krebs cycle takes place in the matrix of the mitochondria. Oxidative phosphorylation via the electon transport chain is carried out on the inner mitochondrial membrane.
In the absence of oxygen, respiration has two metabolic pathways: glycolysis and fermentation. Both of these occur in the cytosol.
In the absence of oxygen, respiration has two metabolic pathways: glycolysis and fermentation. Both of these occur in the cytosol.
Photosynthesis
Photosynthesis was one of our hardest units we have studied so far. It consists of many different complex cycles and reactions that are difficult to remember and understand. The two main things we learned about under the topic of photosynethis was the Calvin Cycle or Light Reaction, and the Dark reaction. Here is a summary of the steps used by plants and other organisms to use solar energy to make chemical energy:
- In plants, photosynthesis usually occurs in the leaves. This is where plants can get the raw materials for photosynthesis all in one convenient location. Carbon dioxide and oxygen enter/exit the leaves through pores called stomata. Water is delivered to the leaves from the roots through a vascular system. The chlorophyll in the chloroplasts inside leaf cells absorbs sunlight.
- The process of photosynthesis is divided into two main parts: light dependent reactions and light independent or dark reactions. The light dependent reaction happens when solar energy is captured to make a molecule called ATP (adenosine triphosphate). The dark reaction happens when the ATP is used to make glucose (the Calvin Cycle).
- Chlorophyll and other carotenoids form what are called antenna complexes. Antenna complexes transfer light energy to one of two types of photochemical reaction centers: P700, which is part of Photosystem I, or P680, which is part of Photosystem II. The photochemical reaction centers are located on the thylakoid membrane of the chloroplast. Excited electrons are transferred to electron acceptors, leaving the reaction center in an oxidized state.
- The light-independent reactions produce carbohydrates by using ATP and NADPH that was formed from the light-dependent reactions.
Active & Passive Transport
Active transport is the movement of a substance against its concentration gradient (from low to high concentration). In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose, and amino acids. If the process uses chemical energy, such as from ATP, it is primary active transport. Active transport uses energy, unlike passive transport, which does not use any type of energy. Active transport is a good example of a process for which cells require energy. Examples of active transport include the uptake of glucose in the intestines in humans and the uptake of mineral ions into root hair cells of plants.
Passive transport means moving biochemicals and other atomic or molecular substances across membranes. Unlike active transport, this process does not involve energy, because, unlike in an active transport, the transport across membrane is always coupled with the growth of entropy of the system. So passive transport is dependent on the permeability of the cell membrane, which, in turn, is dependent on the organization and characteristics of the membrane lipids and proteins. The three main kinds of passive transport are diffusion, facilitated diffusion, and osmosis..
Passive transport means moving biochemicals and other atomic or molecular substances across membranes. Unlike active transport, this process does not involve energy, because, unlike in an active transport, the transport across membrane is always coupled with the growth of entropy of the system. So passive transport is dependent on the permeability of the cell membrane, which, in turn, is dependent on the organization and characteristics of the membrane lipids and proteins. The three main kinds of passive transport are diffusion, facilitated diffusion, and osmosis..
The Cell
The second unit we are learning is the cell. We are learning about plant, animal, and bacteria cells and how their structure is set up and what their function is. We learn many different parts of the cell such as the endoplasmic reticulum, the golgi aparatus, the cell wall and membrane, the nucleus, lysosomes, ribosomes, and other parts. In this unit we get to do many labs using microscopes which keeps the topic interesting and fun. This unit is much easier than inorganic and organic chemistry and is more about memorization than understanding how everything works.
Organic Chemistry
In Level One Biology at Somerset High school the first two units we have been doing are Inorganic and Organic Chemistry. In this unit we will learn about the composition of matter, protons, neutrons, electrons, compounds, mixtures, energy and many other subjects. The hardest part of this unit is memorizing and learning to use the PH scale chart and learning about atomic structures, but the unit is just difficult in general.