Definition of animal cell
Animal cell is a eukaryotic cell without a cell wall that is surrounded by a plasma membrane. The plasma membrane encloses all of the cell organelles, including the nucleus. Plant cells contain a cell wall, in contrast to animal cells, which do not.
- Three-quarters of all species on earth are comprised of the varied group of living things known as animals. All these systems are improved by their component parts of the body, which allow them to move, react to stimuli, adjust to environmental changes, and engage in various forms of eating, defensive mechanisms, and reproduction. Animals, on the other hand, cannot produce their own food as plants can, thus they are in some manner dependent on plants.
- All living creatures are composed of cells, which form the framework of their bodies. Some of these biological entities are multicellular, while others are single-celled (unicellular) (multicellular).
- The smallest (microscopic) structural-functional unit of an organism is called a cell. Animal cells and plant cells are the two types of cells that make up an animal or a plant, respectively.
- The cell wall is a protective membrane that covers the majority of cells and gives them their form and stiffness.
- Animal cells are able to generate a wide variety of cell types, tissues, and organs since they do not have a stiff cell wall. Because plant cells cannot develop into the specialised cells that make up the nerves and muscles, only living things can move their nerve and muscle cells.
Animal cell size and shape
- Animal cells may range in size from a few millimetres to micrometres and come in a variety of forms and sizes. The ostrich egg, which has a 5-inch diameter and weighs between 1.2 and 1.4 kg, is the biggest animal cell, whereas neurons, with a diameter of around 100 microns, are the smallest.
- Animal cells are smaller than plant cells and, because they lack a cell wall, are often irregular in shape, taking on a variety of shapes. Some cells are square, rectangular, spherical, concave, flattened or rod-shaped. The absence of a cell wall is the cause of this. The majority of cells are tiny, so studying their anatomy requires using a microscope to see them.
- However, since both plant and animal cells sprang from eukaryotic cells, they share several cellular organelles.
- Animal cells are eukaryotic cells with a membrane-bound nucleus, as was previously mentioned. Consequently, they have DNA that is contained inside the nucleus and serves as their genetic material. Additionally, the plasma membrane contains a number of structural organelles that carry out a variety of particular tasks for appropriate cell function as well as generally to maintain the body’s regular physiological processes.
List of animal cell organelles
- Plasma membrane (cell membrane)
- Endoplasmic Reticulum (ER)
- Golgi apparatus (Golgi bodies/Golgi complex)
- Cilia and Flagella
Animal cell structure
The animal cell has a number of structural organelles that are encased in the plasma membrane. These organelles allow the cell to operate correctly and trigger host-beneficial actions (animal). An animal’s capacity to move, reproduce, react to stimuli, digest and absorb food, etc., is a result of all of its cells functioning together. The regular operation of the organism is often made possible by the united efforts of all animal cells.
Animal cell organelles
The main cell organelles consist of:
Definition of Plasma membrane (Cell membrane)
An animal cell is encased in a thin, semipermeable protein membrane.
Structure of the plasma membrane (cell membrane)
- Semi-permeable thin membrane
- A portion of the lipids in it provide a semi-permeable barrier between the cell and its physical surroundings.
- It has a small amount of protein.
- Around the cell, it is fairly constant.
- Plasma membranes are found on every live cell.
Functions of the plasma membrane (cell membrane)
- Enclose and safeguard the contents of the cell.
- To control the molecules that move across the plasma membrane and into and out of the cell. As a result, it maintains homeostasis.
- In order to move materials across the membrane, the proteins must be actively engaged.
- Carbohydrates (sugars and sugar chains), which adorn both the proteins and lipids, aid in cell recognition, enable cell communication, and assist cells in identifying one another.
Definition of Nucleus
- This is an organelle with a spherical shape that is mostly located in the cell’s core and is isolated from the cytoplasm by a double-layered nuclear membrane.
- With the aid of microtubules and filaments, it is connected to the cytoplasm.
- It contains the nucleolus, nucleosomes, and chromatin, among other cellular organelles.
- A cell has one nucleus, which divides to create multinucleated cells, such as the fibres of the skeletal muscle.
- After maturation, certain cells, like red blood cells, lose their nuclei.
Structure of the Nucleus
- The endoplasmic reticulum network’s endoplasmic reticulum double-layered membrane is a continuous channel of membranous.
- Large molecules may enter the membrane via holes.
- The nucleus contains tiny or small structures known as nucleoli (singular: nucleolus).
- The nucleus is suspended in the nucleoplasm together with its constituent organelles (house of the chromosomal DNA and genetic materials).
Functions of the Nucleus
- The nucleus’ principal function is to sustain cell metabolisms and govern and regulate cellular growth.
- Additionally, it contains the genes that make up the cell’s genetic makeup.
- The amino acid sequences of the proteins produced by the chromosomal DNA and genetic materials, which are composed of genetic code, are eventually used by the cell.
- As a result, the information hub is the core.
- It is the location of transcription, which produces mRNA from DNA and transports it to the nuclear envelope.
Definition of Cytoplasm
- All of the cell organelles are contained inside the cell membrane, which is a gel-like substance.
- These organelles consist of vesicles, intermediate filaments, microfilaments, microtubules, lysosomes, ribosomes, endoplasmic reticulum, and Golgi apparatus.
Definition of Mitochondria
- All eukaryotic cells include these membrane-bound organelles in their cytoplasm.
- Depending on the task each cell does, each cell has a different number of mitochondria.
- For instance, muscle and liver cells contain hundreds of mitochondria, but erythrocytes do not.
Structure of Mitochondria
- They range in size from 0.5 to 10 m and have a rod-like, oval, or spherical form.
- The outer and inner membranes of mitochondria are two distinct membranes.
- In the middle of the bulk, there is a mitochondrial gel matrix.
- Cristae, or curved folds, are formed by the membranes.
Functions of Mitochondria
- They are the power generators, creating energy in the form of adenosine triphosphate (ATP), which allows the cell to carry out its task as well as discharge extra energy from the cell. Their main job is to produce energy for the cell.
- Additionally, mitochondria store calcium, which helps in cell communication, produces mechanical and cellular heat, and regulates cellular development and death.
- Small molecules can go through the outer membrane because it is permeable, while big molecules may move via a separate channel.
- Since the inner mitochondrial membrane is less permeable, extremely tiny molecules may enter the core mass’s mitochondrial gel-matrix. Tricarboxylic Acid (TCA) cycle or Kreb’s Cycle enzymes and mitochondrial DNA make up the gel matrix.
- The nutrients are depleted by the TCA cycle, which transforms them into byproducts that the mitochondria utilise to produce energy. Because the membrane curves into folds called cristae, where the protein components for the cells’ primary energy generation mechanism, known as the electron transport chain, are located, these activities take place in the inner membrane (ETC). The body’s primary mechanism for producing ATP is called ETC.
- In order to move electrons from one protein component to another and generate energy for the phosphorylation of ADP (adenosine diphosphate) to ATP, the ETC uses a number of oxidation-reduction processes. The chemiosmotic coupling of oxidative phosphorylation is the name of this mechanism. Most cellular processes, including muscular movement, are given energy by this system, which also powers up overall brain activity.
- The cell nucleus supplies some, if not all, of the proteins and chemicals that make up the mitochondria. Thirty-seven genes make up the mitochondrial nucleus genome, and the majority of the ETC’s components are produced by 13 of these genes. However, since mitochondrial DNA lacks a significant DNA repair mechanism, a characteristic of other nuclear DNAs, it is very susceptible to mutations.
- Furthermore, due to the mitochondrion’s predilection for aberrant free electron generation, reactive oxygen species (ROS), also known as free radicals, are created there. Antioxidant proteins in the mitochondrion neutralise these electrons. However, certain free radicals may harm the DNA in the mitochondria (mtDNA).
- Alcohol consumption can also harm mtDNA because too much of it makes the body’s detoxifying enzymes saturated. This results in the production and leakage of highly reactive electrons into the mitochondrial matrix and the cytoplasmic membrane, where they combine with other molecules to form numerous radicals that seriously harm cells.
- The majority of creatures get their mother’s mtDNA. This is so that the embryo may get the majority of the cytoplasm from the mother’s egg while losing the mitochondria from the father’s sperm. Due to mutations passed into the embryo from the maternal and paternal DNA or maternal mtDNA, this is the root cause of hereditary and acquired mitochondrial disorders. Alzheimer’s and Parkinson’s illnesses are two examples of these conditions. Aging and the emergence of several malignancies and disorders have been related to the accumulation of altered mtDNA over time.
- Due to changes in the mtDNA, mitochondria naturally play a significant part in programmed cell death (apoptosis), which may suppress cell death and lead to the growth of cancer.
Definition of Ribosomes
- They are tiny organelles that are mostly composed of 40% proteins and 60% cytoplasmic granules of RNA.
- All live cells include ribosomes, some of which are attached to the endoplasmic reticulum and others of which may circulate freely in the cytoplasm.
- It is where proteins are created.
Structure of Ribosomes
- Both ribosomal RNA and ribosomal proteins make up ribosomes (rRNA). Ribosomes in eukaryotic cells are made up of 50 percent ribosomal RNA and 50 percent ribosomal proteins.
- Each ribosome consists of two subunits, a big and a small subunit, each with a unique shape. The animal cell refers to these components as the 40s and 60s.
Functions of Ribosomes
- About one-fourth of all cellular organelles—ribosomes, which also exist as free particles—are connected to the endoplasmic reticulum membrane. About 10 million ribosomes are present in a single replicating cell.
- Genetic information is coded into proteins at the ribosomal subunit level. The mRNA aids in determining the coding for transfer RNA (tRNA), which also establishes the amino acid sequences of proteins on the ribosomes. This results in the production of rRNA, which catalyses peptidyl transferase to produce the peptide bond that connects amino acid sequences to make proteins. The newly created proteins then separate from the ribosomes and go to other cell components where they may be used by the cell.
Endoplasmic Reticulum (ER)
Structure of the Endoplasmic Reticulum (ER)
- This is a continuous folded membrane organelle that links the cytoplasm to the cell nucleus and is made up of a thin network of flattened linked compartments (sacs).
- There are membranous gaps inside its membranes known as cristae spaces, and the membrane folding is known as cristae.
- Rough endoplasmic reticulum and Smooth endoplasmic reticulum are two different forms of ER based on their shape and function.
Functions of Endoplasmic Reticulum (ER)
- producing, digesting, and moving proteins for both inside-and outside-the-cell use. This is due to the fact that it is directly attached to the nuclear membrane, allowing a passage between the cytoplasm and nucleus.
- Chemical reactions may occur on a significant portion of its surface since the ER contains more than half of the membrane-containing cells. They are the location for lipid synthesis since they are also the source of practically all cell lipid production enzymes.
Rough and smooth endoplasmic reticula are the two forms of ER, which are distinguished by differences in their physical and functional properties.
Types of Endoplasmic Reticulum
- Rough Endoplasmic reticulum: Endoplasmic reticulum has a rough surface, often known as rough ER. Ribosomes cover its surface, giving it a rough look. The ribosomes on the rough ER contain a signalling sequence that directs them to the endoplasmic reticulum for processing, where they synthesise proteins. Proteins and lipids are carried by the ER into the cristae by the cell. They are then either implanted into the cell membrane or sent into the Golgi bodies.
- Smooth endoplasmic reticulum:Even though it is located next to the rough endoplasmic reticulum, the smooth endoplasmic reticulum (Smooth ER) is not connected to ribosomes and has a distinct function from that of the rough endoplasmic reticulum. Its purpose is to create new cellular membranes by synthesising lipids (such as cholesterol and phospholipids). Additionally, they help certain cell types produce steroid hormones from cholesterol. Additionally, it helps the liver detoxify itself after ingesting toxic chemicals and drugs.
- The sarcoplasmic reticulum is another distinct kind of smooth ER. Its job is to control the amount of calcium ions in the cytoplasm of muscle cells.
Golgi apparatus (Golgi bodies/Golgi complex)
Structure of Golgi apparatus (Golgi bodies)
- These are membrane-bound cell organelles that may be discovered in the cytoplasm of eukaryotic cells, close to the nucleus and the endoplasmic reticulum.
- Cytoplasmic microtubules hold golgi bodies together, while a protein matrix holds them in place.
- It is composed of cisternae, which are flattened stacks of pouches.
- For animal cell Golgi bodies, these cisternae may number four to ten, whereas other species, such as single-celled creatures, contain roughly sixty cisterns.
- They contain three main compartments: the medial (cisternae’s middle layers), the trans, and the cis (cisternae nearest the endoplasmic reticulum) (cisternae farthest from the endoplasmic reticulum).
- Plant cells contain a few hundred Golgi bodies compared to only a handful in animal cells (1-2).
Functions of the Golgi apparatus (Golgi bodies)
- Their main duty is to convey proteins and lipids to their intended places by moving, modifying, and packing them into Golgi vesicles. Plants have a few hundred Golgi bodies, compared to one or more in animal cells.
- The cis and trans faces of the cisternae are covered by the cis and trans Golgi network, which is in charge of sorting the proteins and lipids that are received at the cis face and discharged by the trans face by the Golgi bodies.
- Clusters of proteins and lipids from fused vesicles are gathered on the cis face. The vesicular-tubular cluster is a specific compartment in which the fused vesicles travel along the microtubules. Between the Golgi apparatus and the endoplasmic reticulum is where you’ll find this compartment.
- The proteins and lipids are delivered into the cis-face cisternae by the vesicle clusters fusing with the cis Golgi network, and as they migrate from the cis face to the trans face, they are transformed into functional units. The internal and extracellular components of the cell get these functional units.
- Modification techniques comprise
- Chain cleavage in oligosaccharides
- Attachment of various side-chain sugar moieties
- Fatty acid addition, phosphate group addition through phosphorylation, and monosaccharide removal occur in the cis and medial cisternae, whereas galactose addition occurs in the trans cisternae.
- The trans-Golgi network sorts the changed proteins and lipids, which are subsequently packed into trans vesicles and transported to the lysosomes or sometimes to the cell membrane for exocytosis. This is aided by receptor-bound ligands that cause protein release and cell fusion.
Lysosomes were first identified as cell vesicles in the 1950s by the Belgian cytologist, Christian Rene de Duve.
Structure of Lysosomes
- Almost all eukaryotic cells include this spherical subcellular organelle.
- Each lysosome is protected by a membrane to protect it from the outside environment since lysosomes are extremely acidic organelles that house the digesting enzymes.
Functions of Lysosomes
- Cellular regeneration, excretion, and the digestion of cellular nutrients all take place here.
- To create new cell materials, lysosomes disassemble macromolecules from the exterior of the cell into smaller components that are then delivered into the cytoplasm via a proton pump.
- Old cells and their fragments, cell waste products, bacteria, and cell detritus are examples of these macromolecule components.
- The hydrolytic enzymes, also known as acid hydrolases, are the digestive enzymes that are located in lysosomes. They break down big molecules into smaller ones that the cell can use.
- Additionally, these enzymes convert major molecules like proteins, carbohydrates, and lipids into smaller molecules like amino acids, simple sugars, and fatty acids.
- Since the pH of the cell ranges from neutral to slightly alkaline, the acidity of the lysosomes prevents the cell from deteriorating itself in the event of lysosomal leakage.
Structure of the Cytoskeleton
- This is a fibrous network made up of several proteins and extended amino acid chains.
- The cytoplasm of eukaryotic cells contains these proteins.
- Additionally, they are composed of three different kinds of minute filaments: intermediate filaments, microtubules, and actin filaments (microfilaments).
Functions of the cytoskeleton
- The cytoskeleton works to organise the cell’s components into a network and to maintain the cell’s shape.
- The filament system network discovered in the cytoplasm of the cell also allowed for uniform mobility of the cell and its organelles.
- Additionally, it maintains the cell’s form by organising some of its constituent parts.
- It has a significant impact on how the cell and certain cell organelles move about in the cytoplasm.
- The minuscule strands comprise:
- Actin filaments, also known as microfilaments, are a network of parallel fibres that play a key role in giving the cell its form. They vary often, assisting the cell in movement and mediating a number of cell processes, including substrate adhesion and mitotic cell division.
- Microtubules are lengthy filaments that help in the movement of daughter chromosomes to developing daughter cells during mitosis.
- As compared to actin and microtubules, intermediate filaments are more stable filaments. They serve as the cell’s actual skeleton and keep the nucleus where it belongs within the body of the cell.
- Additionally, it permits the cell’s elasticity component to relax, which enables it to withstand physical stress.
- Other proteins that might be included in the cell’s cytoskeleton include spectrin and septin, which are responsible for assembling the filaments (help maintain the structure of the cell by pulling together the cell membrane with the intracellular surface of the cell).
Structure of Microtubules
- Tubulin, a unique globular protein present solely in eukaryotic cells, is a long, straight, hollow cylinder filament made up of 13–15 protofilaments (sub-filaments).
- They are dispersed all across the cytoplasm of animal cells.
Functions of Microtubules
- Transporting vesicles from the neuron cell body to the axon terminals and back to the cell body, as well as certain organelles like the mitochondria.
- They provide the Golgi bodies with their distinctive structural support, keeping them in the cytoplasmic gel matrix.
- They provide the organised and rigid part of the cell’s cytoskeleton that allows a cell to adopt a specific shape.
- They are the primary components of a cell’s locomotive projections (cilia and flagella).
- Additionally, they help the cell’s chromosomes create spindle fibres during mitotic cell division.
Animal cells, which have the capacity to independently reproduce or create duplicates, are a clear example of this. There are nine microtubule bundles in it, and their main job is to help organise the cell division process.
Structure of Centrioles
- A total of nine sets of microtubules, or triplet microtubules, are arranged in this little structure in groups of three.
- They are found in structures like cilia and flagella because, as triplets, they stay exceedingly strong together.
- The proteins that hold the triplet microtubules together give the centriole its form.
- They produce and maintain microtubules inside of the cell at the centrosome.
- A pericentriolar matrix, which contains the molecules that make up the microtubules, surrounds the triplet microtubules.
- The tubulin subunits in each microtubule of the triplet microtubule complex unite to produce long, hollow tubes that resemble straws (microtubules).
Functions of Centrioles
- The transport of chemicals bound together with a glycoprotein to any cell site is made possible by the centriole microtubules. To move certain proteins, the glycoprotein linkage functions as a signalling unit.
- The centrioles serve as an anchor for the microtubules that branch from them and house the components required to produce further tubules.
- Each centriole replicates in order to produce copies, which triggers mitosis (4 centrioles). Each centriole in the freshly generated centrioles divides into two centrosomes at an angle to the other centriole. The centriole pairs are pushed to opposite ends of the cell by the microtubules that connect the centrosomes. The microtubules reach into the cell cytoplasm when the centrioles are in position to look for the chromosome. At the centromere, the microtubules then attach to the chromosome. The chromosomes are then separated by the centriole once the microtubules are disassembled.
These are tiny structures located in the cytoplasm.
Structure of Peroxisomes
- The most prevalent micro-bodies in a cell’s cytoplasm are spherical, membrane-bound structures.
Functions of Peroxisomes
- Peroxisome functions include:
- Lipoprotein synthesis
- Chemical detoxification neutralises biological toxins like alcohol by transferring hydrogen atoms from different oxygen molecules to form hydrogen peroxide.
- In reactive oxygen species, their mechanism is very crucial.
Flagella and cilia
These are locomotive projections that may be seen on the cell’s outside.
Cilia and Flagella’s structural makeup
- They are constructed from filamentous strands. These microtubules, both incomplete and complete, expand the projections on these filaments. In contrast to partial microtubules, which do not reach the cilium’s apex, full microtubules do.
- Dynein, a motor protein in the microtubules, connects the incomplete microtubules to the full microtubules.
- The entire group is attached to the cell’s plasma membrane as extensions.
Functions of cilia and flagella
- Flagella on sperm cells enables them to swim to the ova for fertilisation. This gives single cells, like sperm, the ability to swim.
- Animal cells’ cilia aid in the movement of fluids past and away from immobile cells.
- Cilia assist in moving mucus and surface particles, particularly on the epithelial lining of the nostrils.
These are membrane-bound vesicles produced by the endocytosis process. They are located in the cytoplasm of the cell.
Structure of Endosome
- They are membrane-bound organelles that are made of membranous material.
- The plasma membrane is folded in as its primary function. Through the extracellular fluids, chemicals may diffuse in due to folding.
- By using endocytic procedures like exocytosis and phagocytosis, their main function is to eliminate waste products from the cell.
These are membrane-enclosed, fluid-filled cell organelles.
Structure of Vacuoles
- They are cytoplasmic sacs that are membrane-bound.
- A tonoplast, a single membrane that surrounds the vacuole sac and is similar to the plasma membrane, is present.
Functions of Vacuoles
- Their main job is to store things like food, water, sugary carbs, and waste.
- Tonoplast is a regulator that regulates the movement of tiny molecules through a protein pump.
- protects what kind of material are permitted transit to and from vacuoles.
- As a defence mechanism, they also remove hazardous elements and trash from the cell.
- Additionally, they eliminate misfolded proteins from the cell.
- Vacuoles may alter their form and size, which allows them to adjust their functioning to play the essential functions that are appropriate for the cell.
These are protrusions on the surface of white blood cells, egg cells, and the lining of the intestine.
Structure of Microvilli
- These are surface protrusions produced by the actin filaments’ auxiliary proteins. On the cell membrane’s surface, the accessory proteins assemble bundles to generate microvilli.
Functions of Microvilli
They expand the surface area in the small intestines where water and food that has been digested may be absorbed. In order to sense sound, the ear may include certain microvilli, which send an electric signal carrying the sound waves to the brain.
They also aid in securing the sperm to the egg to facilitate simple fertilisation.
They also serve as anchors for white blood cells, enabling them to travel freely in the bloodstream and connect to potential pathogens.
References and Sources
1% – https://www.britannica.com/science/mitochondrion
1% – https://www.britannica.com/science/Golgi-apparatus
1% – https://hrcak.srce.hr/file/299589
1% – https://biologydictionary.net/centriole/
<1% – https://www.youtube.com/watch?v=ubzw64PQPqM
<1% – https://www.youtube.com/watch?v=MWz4ptP_QEU
<1% – https://www.youtube.com/watch?v=HxdajtjxRvg
<1% – https://www.thoughtco.com/the-cell-nucleus-373362
<1% – https://www.thoughtco.com/ribosomes-meaning-373363
<1% – https://www.thoughtco.com/dna-transcription-373398
<1% – https://www.thoughtco.com/all-about-animal-cells-373379
<1% – https://www.shmoop.com/biology-cells/plasma-membrane.html
<1% – https://www.sciencedirect.com/topics/neuroscience/reactive-oxygen-species
<1% – https://www.sciencedirect.com/topics/neuroscience/cilium
<1% – https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/outer-mitochondrial-membrane
<1% – https://www.quora.com/What-is-the-main-function-of-a-vacuole-in-a-plant-cell
<1% – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169682/
<1% – https://www.nature.com/articles/352441a0
<1% – https://www.golifescience.com/cytoskeleton/
<1% – https://www.genome.gov/genetics-glossary/Lysosome
<1% – https://www.earthslab.com/physiology/endoplasmic-reticulum/
<1% – https://www.britannica.com/science/ribosome
<1% – https://www.britannica.com/science/lysosome
<1% – https://www.britannica.com/science/cytoskeleton
<1% – https://www.assignmentpoint.com/science/biology/about-lysosome.html
<1% – https://www.answers.com/Q/Which_part_of_the_cell_is_composed_of_microtubules_and_helps_move_chromosomes_around_during_cell_division
<1% – https://www.answers.com/Q/Where_are_calcium_ions_stored_in_the_muscle_cell
<1% – https://www.answers.com/Q/What_are_the_cell_organelles_that_present_only_in_eukaryotic_cell
<1% – https://www.answers.com/Q/What_are_organisms_made_of_only_one_cell_called
<1% – https://study.com/academy/lesson/microtubules-definition-functions-structure.html
<1% – https://sciencing.com/two-types-endoplasmic-reticulum-8431592.html
<1% – https://s3.amazonaws.com/scschoolfiles/631/12-2-2016_cells_vocabulary_list___definitions.pdf
<1% – https://quizlet.com/89275056/biology-ch-6-flash-cards/
<1% – https://quizlet.com/72683765/cells-flash-cards/
<1% – https://quizlet.com/69658683/cells-of-nervous-system-flash-cards/
<1% – https://quizlet.com/6888669/cell-organelles-flash-cards/
<1% – https://quizlet.com/55382975/biol380-quiz-4-prep-flash-cards/
<1% – https://quizlet.com/49817904/cell-bio-1-flash-cards/
<1% – https://quizlet.com/46072103/nutrition-chapter-three-flash-cards/
<1% – https://quizlet.com/44872957/chapter-14-genetics-flash-cards/
<1% – https://quizlet.com/33098973/bio-cell-vocab-flash-cards/
<1% – https://quizlet.com/2170816/ocr-gce-biology-as-flash-cards/
<1% – https://quizlet.com/188524822/ch-6-bacterial-growth-nutrition-and-differentiation-flash-cards/
<1% – https://quizlet.com/177529878/bio-test-4-flash-cards/
<1% – https://quizlet.com/144988079/cytoskeleton-and-cell-movement-flash-cards/
<1% – https://quizlet.com/11540101/characteristics-of-life-flash-cards/
<1% – https://quizlet.com/113339181/bio-cell-membrane-flash-cards/
<1% – https://quizlet.com/11324905/cell-and-organelles-flash-cards/
<1% – https://quizlet.com/101245749/plasma-membrane-cell-membrane-flash-cards/
<1% – https://pdb101.rcsb.org/motm/10
<1% – https://micro.magnet.fsu.edu/cells/plants/vacuole.html
<1% – https://in.answers.yahoo.com/question/index?qid=20070225082506AA8X0Zo
<1% – https://ghr.nlm.nih.gov/primer/basics/gene
<1% – https://ghr.nlm.nih.gov/primer/basics/cell
<1% – https://fqresearch.org/pdf_files/Reactive-Oxygen-Species-and-Aging.pdf
<1% – https://en.m.wikipedia.org/wiki/Inner_mitochondrial_membrane
<1% – https://courses.lumenlearning.com/boundless-biology/chapter/the-cytoskeleton/
<1% – https://courses.lumenlearning.com/boundless-biology/chapter/bulk-transport/
<1% – https://byjus.com/biology/animal-cell/
<1% – https://bscb.org/learning-resources/softcell-e-learning/ribosome/
<1% – https://brainly.com/question/5430031
<1% – https://brainly.com/question/2779157
<1% – https://biologywise.com/plant-cell-organelles
<1% – https://biologywise.com/cell-membrane-structure-function
<1% – https://biologydictionary.net/smooth-endoplasmic-reticulum/
<1% – https://alevelbiology.co.uk/notes/organelle-structure-function/
<1% – https://academic.oup.com/biomedgerontology/article/56/11/B475/591131
<1% – http://www.cytochemistry.net/cell-biology/cilia.htm
<1% – http://www.biologyreference.com/Co-Dn/Cytoskeleton.html
<1% – http://new-show.pw/10175215158/142/rough-endoplasmic-reticulum.html