All living things are made up of units called cells. A cell, the basic unit of life, is a microscopic structure that forms the basic structural as well as functional unit of living organisms. Cells can be divided into two categories called prokaryotic and eukaryotic cells. Prokaryotic cells are simple cells that lack nucleus and membrane bound organelles whereas, eukaryotic cells are more complex cells comprising nuclear and cytoplasmic material sheathed by a cell membrane. Both plants and animals consist of eukaryotic cells. Eukaryotic cells have a standard set of features, however, plant and animal cells do have their differences. Let us take a look at the similarities between plant and animal cells.
Plants and Animal Cell Similarities
Similarities between plant and animal cells comprise a standard set of features such as:
Cell Membrane: Also known as plasma membrane, this membrane is the outermost limiting membrane of the cell that encompasses all the cell contents. This membrane is formed from proteins and lipids and acts as an interface between the cell organelles dunked in the cytoplasm inside the cell and the extracellular fluid on the cell's exterior, which bathes all the cells. It is a semi-permeable membrane and permits the passage of selective substances from the exterior to the interior of the cell and vice versa. Besides this main membrane, the cell also features elaborate network of internal membranes which envelop the different cell organelles, forming several membrane-enclosed compartments within the cell. Read more on plant cell model.
Cell Nucleus: The hallmark of eukaryotic cells is the presence of a membrane bound nucleus in the cell. The very term 'eukaryotic' means possessing a 'true nucleus'. Plants and animal cells have a nucleus, which is a spherical body containing several organelles, nucleolus and chromosomes consisting of DNA. The nucleus is enveloped by a nuclear membrane, which keeps the contents of the nucleus from dissipating into the cytoplasm of the cell. The nucleus controls various functions of the cell by controlling protein synthesis. Read more on cell nucleus: structure and functions.
Mitochondria: These are cell organelles enclosed by membranes and are scattered in the cytoplasm of the cell. Mitochondria features an outer membrane that encloses the entire structure and an inner membrane that encloses a fluid-filled matrix. The inner membrane features shelf-like cristae projecting into the matrix. It also possesses some 5-10 circular molecules of DNA. Mitochondria are cells responsible for the conversion of potential energy of the food molecules into ATP. Thus, these are the powerhouse of the cell. Their numbers will vary from a few hundreds to some thousands in the cell, depending on how active the cell is. Mitochondrial cells can increase their number by a process of fission and can reduce their numbers by fusing together. Read more on mitochondrial DNA.
Endoplasmic Reticulum (ER): It is an extensive membranous labyrinth, which accounts for half the total membrane in eukaryotic cells. The term 'endoplasmic' means within the cytoplasm and 'reticulum' refers to network. ER consists of a network of membranous sacs and tubules called cisternae. There are two types of ER - rough ER and smooth ER. Rough ER is the endoplasmic reticulum that has a bumpy appearance due to the presence of ribosomes attached to them. The smooth ER does not have ribosomes adhering to them. Rough ER is responsible for protein synthesis, while the smooth ER synthesizes lipids and is responsible for carbohydrate metabolism and detoxification of drugs and other poisons.
Ribosomes: These are small, spherical, non-membranous organelles composed of ribonucleic acid (RNA). Ribosomes comprise 65% ribosomal RNA and 35% ribosomal proteins. They are responsible for protein synthesis and are sites where the cell assembles proteins in accordance to the genetic instructions obtained. Cells which have high protein synthesis rate feature the presence of a large number of ribosomes. Ribosomes are found scattered in the cytoplasm as well as adhering to the outer portion of the endoplasmic reticulum.
Golgi Apparatus: These are stacks of cisternae (flattened sacs of unit membrane) that are mainly devoted to processing the proteins formed in the ER. Their job is to transform proteins into more complex molecules. The Golgi complex also contains a large number of vesicles, which are used to send molecules to the cellular membrane, where excretion is carried out. The Golgi apparatus is mostly responsible for molecular traffic direction in the cell.
These were the similarities between plant and animal cells. However, besides these similarities, plant and animal cells have a few differences. For example, plant cell organelles include a cell wall that surrounds the cell membrane, thereby making the cells in plants more sturdy. They also contain chloroplasts which capture sunlight for photosynthesis and a large central vacuole for water storage. Animal cells contain organelles called centrioles, responsible for animal cell division, which are not found in plant cells. Moreover, animal cells also possess lysosomes that perform the same role as the vacuole in the plant cell. Hope this article on similarities between plant and animal cells informative and enlightening!