Cell biology is the study of cells and how they function. It is a branch of biology that deals with the chemistry, structure, physiology, genetics and molecular biology of cells. Cell biologists work on all kinds of living organisms from single-celled organisms like bacteria to more complex ones like plants and animals.
Biophysics is a branch of physics that deals with the physical properties of biological systems. It is an interdisciplinary field that applies the laws and theories of physics to biological and medical problems. Biophysics covers a wide variety of topics, including how cells work at a molecular level, how biological systems respond to stimuli (such as light), how organisms such as plants or animals move, how complex behaviors such as learning and memory occur, and even the study of quantum effects in biology.
A lot has happened since physicists first started studying biology—so much so that biophysics has become its own subfield within physics rather than being considered just one aspect of something else. Biologists now know more about what happens at every level within cells; they have developed many new techniques for investigating cellular processes; they are even learning how to manipulate these processes by applying engineering principles from outside science fields (such as computer programming) into biology research!
The word cell means "tiny room". It's the smallest unit of structure, function, and behaviour in all living things.
There are many different kinds of cells, each with its own unique function. Cells are the basic building blocks of life on Earth. There are millions of cells in your body right now!
All animals and plants consist of many different types of cells; they have a variety of shapes and sizes depending on their functions within an organism (organism refers to something that can live independently). For example:
Cells are the fundamental unit of life, and the cell membrane is what separates cells from the outside world. Membranes are made up of a double layer of phospholipids that form a barrier to keep out larger molecules. This can be helpful when it comes to transporting proteins across membranes into or out of cells. Proteins found in this space include ion channels and transporters that help transport ions such as sodium and potassium across membranes to maintain homeostasis within cells.
Mitochondria are the cell's powerhouses, making the energy that fuels all of our cells. Chloroplasts are the organelles that carry out photosynthesis in plant cells; they transform light energy into chemical energy for plants to use as fuel.
Cellular respiration is the process of converting food and oxygen into energy. Oxygen is necessary for cellular respiration because it acts as a source of electrons that fuels the production of ATP, which then fuels many other processes in cells. In eukaryotic cells (cells with a nucleus), energy from glucose is released through cellular respiration when it enters the mitochondria—the cell's power plants—through special channels called enzymes. This process occurs in two stages:
You've probably heard of signal transduction pathways, but what exactly are they? A signal transduction pathway is a way that signals are passed from one part of the cell to another. The most common form of signal transduction is through hormones like epinephrine (adrenaline), which bind to receptors on the surface of cells and cause changes inside those cells.
Signal transduction pathways often have effectors – proteins that carry out the changes in response to a particular hormone or other trigger molecule binding to its receptor. An example would be cyclic AMP, which is an intracellular messenger molecule; it's activated by adenosine diphosphate (ADP) and cyclic guanosine monophosphate (cGMP) binding with their respective receptors on a cell's surface. When activated by these extracellular ligands, cyclic AMP activates protein kinase A which phosphorylates certain enzymes in order for them to function properly within the cell
Cell-cell communication is a crucial part of the cellular processes that keep your body functioning. When cells talk to each other, they use chemical signals to send messages from one cell to another. This kind of communication happens all the time—for example, when a cell grows and divides into two new cells or when immune cells attack an invading germ. Sometimes, however, cells can communicate with each other without using chemical signals. For example, when you take aspirin for a headache it works because it blocks the COX-1 enzyme responsible for cramping muscles during exercise (the COX-2 enzyme does this instead).
Cell differentiation is the process by which a cell commits to a particular fate. For example, some cells in your body specialize into muscle cells, while others become skin or brain cells. The first step in differentiating is typically when a cell begins expressing certain proteins on its surface, called markers; these markers tell other nearby cells what kind of cell it should become. Differentiation is often studied in embryonic stem (ES) cells because they're able to differentiate into any type of mature cell in the body and can be generated from just about any tissue type.
Cellular senescence is the phenomenon of cells ceasing to divide. It occurs in many types of human cells as they age, and cellular senescence can also be induced by telomere shortening.
Telomeres are found at the end of each chromosome, and their length decreases over time as a cell divides. When a cell reaches its Hayflick limit (the number of times it can divide) before its telomeres have been shortened enough, the cell becomes senescent to prevent further division. In this way, telomerase activity prevents or slows down cellular senescence by adding more bases onto the ends of chromosomes so they don't become shorter with each division.
As you can see, cell biology is a very broad field that includes many different aspects of cell function. It's important to remember that while we have covered some of the most common applications here, there are many more potential uses for this knowledge! The applications are endless: from designing new drugs and treatments for diseases like cancer or Alzheimer's disease (which we'll be looking at soon), to developing new products like cosmetics based on natural ingredients instead of chemicals. In fact, we're already seeing some innovative uses being developed right now—for example, scientists have found ways to modify human cells so they produce insulin when needed without requiring an external supply; by using this type of technology someday people with diabetes may no longer need daily injections into their bodies!