What are Cells?
Cells are the basic unit of life and has all the characteristics of living things. It is the smallest unit of life that can live on its own. There are two kinds of cells: eukaryotic cells and prokaryotic cells. Eukaryotic cells have a nucleus like YOU (an easy way of remembering eukaryotic cells), while prokaryotic cells have DNA that are not surrounded by a nucleus.
Animal Cells and Plant Cells
Animal cells are cells that can move freely, like regular animals, while plant cells stay still and "stand". Also, plant cells have an extra "skin" called the cell wall and are able to store more water than the animal cells.
Parts of a cell
The Organelles
An organelle is actually a small organ of the cell and are the parts of the cell. All eukaryotic cells have organelles, but all cells don't have the same ones, especially between the animal and plant cells.
The Cytoplasm
The cytoplasm is the jelly-like substance that the other parts of the cell, or organelles, sit on. It is also the substance that allows the cell to grow and reproduce. So, basically, the cytoplasm is protein rich. It moves constantly and moves in a wave-like motion.
The Cell Membrane
The cell membrane is in both the animal and plant cells. It is a outside layer that wraps around the cell the same way the skin does for a human being. It also gives the cell shape and controls what goes in and out of the cell. When it chooses what goes in or out, it is very selective, or picky. However, it allows certain things like water or carbon dioxide to pass through easily.
The Mitochondria
The mitochondria are oval sacs that are abundant in a cell. Mitochondria have membranes that are folded in the insides, and these folds give the mitochondria more surface area (SA). Because of this, it allows the mitochondria to work harder for the cell. Just one mitochondrion breaks down food and converts into energy. Also, if a cell, such as a human liver cell, needs more energy, it will usually have more mitochondria.
The Vacuoles
Animal vacuoles are different from plant vacuoles. Animal vacuoles store things such as water, food, and wastes, and the nucleus can send a signal to the vacuole to release anything it is holding. Also, animal cells usually has small vacuoles and may not have none at all.
With plant cells, they only have one major vacuole per cell. They store water and provide support, like the cell wall. Also, if a plant doesn't get enough water, the vacuoles release the remaining water and causes them to shrink. This makes the plant cells to shrink and make the plant itself to bend over (and vice versa).
With plant cells, they only have one major vacuole per cell. They store water and provide support, like the cell wall. Also, if a plant doesn't get enough water, the vacuoles release the remaining water and causes them to shrink. This makes the plant cells to shrink and make the plant itself to bend over (and vice versa).
The Nucleus
The nucleus is located in the center of the cell and is the "brain of the cell" that contains DNA. It is a spherical structure that has pores, or holes/openings, that allow certain things to pass in or out. As for being the brain of the cell, it controls all the activity and sends signals to other parts to the cell, such as when it is time to break down food or even when it's time to die.
DNA, or deoxyribonucleic acid, was made out of sugars, bases, and phosphate. There are four types of bases: adenine (A), thymine (T), guanine (G), and cytosine (C). In DNA strands, adenine matches with thymine, while cytosine matches with guanine. The first picture, an x-ray of a DNA was taken by Rosalind Franklin, which looks like a circle with an X in the middle. In 1953, James Watson and Francis Crick come up with the correct structure for DNA - double helix.
The Chloroplast
A chloroplast is an organelle that is not in animal cells, but in plant cells. They are mostly in plant cells, because some protists also have them. In the chloroplast, there is a pigment called chlorophyll, and this is where the process photosynthesis takes place. The chlorophyll in the chloroplasts make the plant look green as well. In addition, the main reason why the leaves change color during the seasons is because the chlorophyll break down.
The Cell Wall
The cell wall is also not in animal cells; it is in plants, fungus, mold, and algae. It provides the structure and support to these cells so that the cell can "stand". The cell wall, a resemblance to the skeletal system, is an outer covering of the cell. Cell walls are made out of the cellulose in plants.