An instrument used to look at very small objects such as cells, viruses, molecules, and even atoms.

It makes use of an optical lens to magnify the image of the small object.

They were first invented in the 1600s.

An instrument used to look at very distant objects such as planets, stars, and other objects in space.

It makes use of the optical lens to change the magnification of the object, which would otherwise appear extremely tiny.

A specifically shaped piece of glass found in microscopes and telescopes.

They were invented very long ago and were first used in corrective eye glasses.

The person who discovered cells. Belonged to the Royal Society of London. Wrote Micrographia.

He cut a piece of cork with a sharp razor and viewed it under a microscope. He saw a structure similar to a honeycomb. He named the pores he saw "cells" after the rooms of monks in a monastery. We know now that what he was seeing was the dead cell walls of the cork tree.

He was the one who confirmed Anton van Leeuwenhoek's discovery of protists and bacteria.

The person who discovered protists and bacteria. Persued science for the curiosity, not the glory.

A clothes and button salesman who spent his spare time making optical lenses and microscopes. Was in correspondence with the Royal Society of London.

He examined a drop of pond water with a microscope and saw moving objects which he named "animalcules". We know now that what he saw were protists or bacteria. He also found bacteria in scrapings from his teeth. 

His findings were met with skepticism until Robert Hooke confirmed his discoveries.

One of the people who helped develope cell theory.

A lawyer and botanist. He was a colleague of Theodor Schwann. In the 1830s he made the discovery that all plants were made from cells and that plant embryos consisted of a single cell.

He made the incorrect assumption that a cell could arise spontaneously from non-cellular material. This notion remained unquestioned for a number of years.

One of the people who helped develop cell theory.

A zoologist. He was a colleague of Matthias Schleiden. He made the discovery that all organisms, including animals and humans, were composed of cell(s), and that the cell was the structural unit of life.

He made the incorrect assumption that a cell could arise spontaneously from non-cellular material. This notion remained unquestioned for a number of years.

The person who debunked the idea of Matthias Schleiden and Theodor Schwann that cells can arise spontaneously from non-cellular material.

A pathologist.

A set of laws of life

1. All organisms are composed of one or more cells.

2. The cell is the structural unit of all life

3. Cells can only arise by division from pre-existing cells.

A property of life. All living things die. All cells die.

Sometimes cells will "commit suicide" due to internal programing or signals from outside. This way an organism can trim off unneeded or dangerous (such as cancerous) cells.

A married couple from Hopkins University.

In 1951 they cultured in vitro the tumor cells of Henrietta Lacks and called them "HeLa" cells, after the donor. They discovered that unlike normal tissues, cancerous tissues can be cultured indefinitely in vitro.

To culture something in a petri dish in a lab.

Cells are much more easily studied this way. This is an essential tool of the cellular biologist.

When a patient gets a bacterial infection one of the first steps of diagnosis is to culture it to see what bacteria it is. We can only record and "discover" bacteria that we can culture, so many species, such as those in the ocean, are left undiscovered.

Living things are arranged in many compound layers of complexity from atoms to organisms. Each layer has a very specifically regulated way its components are arranged. Even small mistakes (at any point) can have life altering effects on the higher levels. At the lower levels there is not much difference between species; for example both humans and trees have the organelles mitochondria.

1. Atoms are arranged into small molecules.

2. Small molecules are arranged into larger polymers.

3. Polymers are arranged into complexes.

4. Polymer complexes are arranged into subcellular organelles.

5. Organelles are arranged into cells.

6. Cells are arranged into organisms.

An organelle that provides usable energy in the form of ATP to the rest of the cell, fueling cell functions. It measures 2 μm in diameter and can be a variety of shapes, even tubular. They reproduce by fission, and can fuse with other mitochondria.

There are two membranes, the OMM and IMM. Its membrane is produced separately from the rest of the cell. Sometimes it sends vesicles to the peroxisomes. When ADP levels drop, it stops producing ATP.

The "blueprints" of an organism. One of the polymers that set life apart from non-living things. The monomers are nucleotides. It is an anti-parallel, right-handed double helix strand 2 nm in diameter composed of the bases guanine, adenine, thymine, and cytosine. The strands are held together by hydrogen bonds. Each strand has a 5' end and a 3' end. More stable than RNA.

Information is stored in its sequences for cell structure, cell activity, and cell reproduction. Proteins are the "workers" who follow the "blueprints". Not all the mechanisms by which cells use and transmit these genes are discovered yet.

Packaged in a set of chromosomes inside the nucleus.  

Humans have enough sequences to fill a million pages of text.

Cells reproduce by division into two smaller cells. The contents of the "mother" cell are distributed to the two "daughter" cells evenly. Prior to the split, all genetic material is duplicated and each "daughter" recieves an equal share of the genes. 

Usually both cells are equal in volume, but there are exceptions, such as in mammalian oocyte division.

Required by all biological processes.

Nearly all lifefroms ultimately get it from the sun. The sun emits it in the form of electromagnetic radiation, which is absorbed by light-absorbing pigments inside photosynthetic cells. Organisms that do not have photosynthetic cells then take it from the organisms that do by eating or absorbing their cells or cell remains.

The sum of an organisms chemical reactions.

Cells must break down and creat chemicals in reactions that would almost never occur spontaneously. They do this with enzymes.

Each step of all processes in a cell must occur chemically spontaneously in a way that triggers the next step of the process. The steps were developed over eons of evolutionary trial and error.

A property of life. Materials are transported in, out, and around a cell, they are assembled or disassembled, and even entire cells can relocate themselves. 

It is done with motor proteins.

A protein that creates all mechanical motion inside a cell or in moving an entire cell.

Push or pull vesicle cargo along the cytoskeleton. Have two "feet" and do a walking motion along the microtubule or microfilament.

The mechanism by which cells are able to protect themselves from dangerous fluctuations in composition. It keeps the cell at homeostasis, even through any changes in cells, such as changes brougt on by external stimuli.

If it is damaged, it can be very bad for a cell, and it can be mutated, become cancerous, and/or die.

An embryologist famous for his experiments with sea urchin embryos.

He discovered that if he separated the first two cels of a sea urchin embryo the two cells would form into two separate but genetically identical sea urchins.

This raises some important questions, such as how does the separated cell know to develop into a full sea urchin, and not half a sea urchin? How does the cell know that its "sister" cell is not there? How does this knowledge alter the way the cell grows?

We still do not fully know the answers.

A polymer that forms very specific shapes, often in larger complexes. One of the polymers that sets life apart from non-living things. It has an amino (N)-terminus and a carboxy (C)-terminus.

They are formed from mRNA sequences and ribosomes. and have a myriad of functions in the cell.

They have a lifespan between a few seconds and a few weeks. They are destroyed by proteasomes.

The mechanism by which organisms develop into different more "advanced" organisms. There is genetic variation between individuals, this is what causes natural selection.

It has been occuring for almost 4 billion years, since LUCA, and is still an ongoing occurance.

"Before nucleus". The "simpler" of the two types of cells.  This kingdom has two domains: Archaea and Bacteria. They are older than eukaryotes. The first definite sign of them (in fossils) is over 2.7 billion years old, but they may be as old as almost 4 billion years. They are very succesful. In terms of numbers they are far more sucessful than eukaryotes. They are better at encorporating foreing DNA and adapting to environments.

There are trillions of them living just on or in you alone; they live in your intestines, making essential vitamins and fighting off pathogens. The species representation of this bacteria may change with different factors such as physical health and diet.

They are 5 to 10 μm in diameter. Because of their morphology they are difficult to see with a microscope and difficult to distinguish between. 6000 species are discovered, but this is an estimated 0.01% of the true number of species.

Their genetic material is kept in a nucleoid. They have less DNA than eukaryotes; they have only one chromosome with a circular DNA strand.

They are small enough that they need no intracellular transport system; diffusion of material is enough to keep the center of the cell nurished.

"True nucleus". The "more advanced" of the two types of cells. This category includes protists, fungi, plants, and animals.

They are younger than prokaryotes, but it is unclear when they first arose, but they are older than 600 million years.

Their nuclei are separated from their cytoplasm by the nuclear envelope. Their DNA is packaged in multiple chromosomes, each containing a linear DNA strand. They have complex, membrane-bound organelles. They have specialized organelles for aerobic respiration and (sometimes) photosynthesis: mitochondria and chloroplasts. They have cytoskeletal systems and an intracellular transport system. They may have flagella and cilia. They may undergo phagocytosis. They may have cellulose-containing cell walls. They form spindles during cell division. There are two copies of genes per cell, one from each parent. They have three different RNA synthesizing enzymes. They may have sexual reproduction with meiosis and fertilization.

An organelle that sorts, modifies, and transports substancea from the ER. Discovered by Camillo Golgi, who gave it his name. It was suspected to be an artifact until freeze-fracturing showed that it was not.

It produces complex polysaccharides. Series of less than 8 flattened stacked membranous cisternae. 0.5 to 10 μm in diameter. It has cis, medial, and trans regions. They are supported by protein scaffolfing (spectrin, ankyrin, and actin) and there are other proteins which aid in replication during mitosis. Each cisternae is chemically unique. There are two theories on how it forms: the cisternal maturation model and the veisicular transport model.

The large, central organelle in a plant cell.Its membrane is calld the tonoplast. It may take up to 90% of the cell's volume. It performs many essential functions. It contains ions, sugars, proteins, toxins, and many other substances. Used for storage and mechanical support. Proteins are produced in the RER.

It may contain toxins as a defense mechanism against herbivores or parasites when the plant is injured.

Plant's down have the same excretory system as in animals, by-products of processes may be dumped in the vacuole. 

It acts as the cell's lysosomes, and it has hydrolytic enzymes in it and a low pH maintained by V-type H⁺-ATPase.

A structure that protrudes from some cells. It is attached to motor proteins and is used to propel a cell through its medium. Some bacteria can rotate theirs 1000 times per second. 

The mechanisms of motion are different in prokaryotes than in eukaryotes.

A domain of the prokaryotes. They are more related to eukaryotes than bacteria.

They can live in very inhospitable environments. They are sometimes called the "extremophiles".

They include methanogens (methane producers), halogens (live in highly salty waters), acidophile (live in very low pH), and thermophiles (live at very high temperatures). Many of these species may also be found in normal conditions.

A domain of prokaryotes. They can live in every conceivable habitat on Earth, even deep beneath the bedrock. Some species divide only once every hundred years!

They have 2500 to 3500 genes, usually on a single DNA molecule.

The process by which cells in a muticellular orgnism are specialized. It occurs in embryos.

They used to think that cells would discard unneeded genes. This was disproved by clones such as Dolly the Lamb.

Each cell has a subset of genes which indicates what genes to activate and what to not activate. Cells in different regions of the embryo take on different sizes, shapes, and chemical compositions. They have different representation and location of organelles. They eventually take on different tasks in the organism.

A model organism. It is a prokaryote found in the human digestive tract.

Using synthetic biology, one company was succesful in incorporating the DNA of 3 other bacterial species to make it produce biofuel ethanol

1. Only one set of chromosomes, constantly bing copied. Only so much mRNA can be produced at a time, limiting cell size.

2. As volume increases surface area to volume ratio shrinks, putting strain on the import/export system of the cell. To circumvent this some cells are very long or have microvillli.

3. Oxygen must diffuse to the center of the cell. Too large a cell will experience oxygen deprivation at its core.

The quest to create a living cell from non-living materials. This has no practical application, it is simply awesome. It would give insight on how LUCA came to be. Scientists are nowhere near accomplishing it. Some people say it would be unethical.

Another branch of this is genetically creating new species out of existing ones for medicine, industry, or the environment.

The group who in 2007 first changed the species of a bacteria. They introduced new DNA to a host and the host changed its characteristics and became a different species.

These methods are now used to create organisms that can produce pharmaceuticals, fuels, or other useful chemicals.

The person who discovered that viruses are not cellular. From the Rockefeller Institute.

In 1935 he crystalized tobacco mosaic disease. This proved that the virus was a well defined shape with an uncomplicated structure, definately not cells.

He incorrectly concluded that viruses were proteins.

The cause of many diseases across all lifeforms. For humans they include HIV, polio, influenza, cold sores, measels, and they can cause some cancers.

They come in a great variety of shapes, sizes, and structures. They cannot reproduce without a living host; each one has a specific range of hosts it can attack. They have no metabolic processes. They are not considered living. 

It exists outside of cells as a free particle called a virion. 

They are a proetin coat surrounding genes inside a capsid. The 3 to 4 genes may be DNA or RNA.

They may be used to conduct scientific research on gene replication and expression. They are used to introduce foreign genes to complex cells. They can be used to treat human diseases. Viruses that effect pests may be used as a form of pest control. 

The protein coat surrounding the genes of a virus. It is formed from a number of proteins. The fewer proteins, the less genes are required for the virus.

Some are polyhedron shaped with planar faces, such as a 20-sided icosahedron.

Some have phospholipids encorporated into them, stolen from their parent host as they exited the cell.

They have proteins on their surface that bind to particular surface components of the host cell and facilitate the virus's entry to the cell. How specific this protein is determines the virus's host range.

Viruses that attack bacteria. In terms of numbers they are the most abundant biological entity on Earth. 

They are the most complicated viruses. They have a polyhedral head containing DNA, a cylindrical neck, and tail fibres. It resemples the moon landing pod.

They may be used to treat bacterial infections as an alternative to antibiotics. They may be used to keep food from bacterial contamination.

A virus that in 1918 killed 30 million people, especially young adults. 

Scientists have been able to recreate the influenza artifically by analysing the preserved tissues of a Native American woman who died of the influenza in 1918 and was buried in permafrost that preserved her body.

The reconstructed virus killed 100% of a population of mice. Only mice who had been vaccinated could survive.

By analyzing the genes, they determined that the disease was passed to humans from birds, probably chickens.

A type of viral infection where the virus does not kill the host cell. Instead it inserts its DNA into the hosts's chromosomes. It can have several effects.

1. The cell behaves normally until exposed to external stimuli that activate dormant viral DNA, leading to lyses.

2. The cell produces virions that bud the cell surface but do not break it. Eample: HIV. The cell remains alive as a virus factory.

3. The host loses control of its growth and division rate and becomes a malignant tumour.

A virus lacking a capsid. It is a naked strand of RNA from 240 to 600 nucleotides, one tenth the size of the smallest viruses. 

All biochemical activities are completed by the host cell. It makes use of polymerase II, the enzyme normally used for making mRNA. 

It kills its host by messing up their normal gene expression path.

Examples: cadang-cadang in coconuts, potato spindle-tuber disease, and a disease that effects chrysanthemums.

The study of cells. It has taken us 400 years to get to the level of knowledge we have on cells today. We still don't know everything. 

50 years ago DNA was discovered, and in the 90s many genomes of organisms were recorded, but this still does not tell us everything.

In a diagram the cell has neatly placed, still organelles. In reality everything is cluttered and moving! Nothing is written in stone.

The lens in a light microscope that takes in the light that is shining through the specimen. It forms an enlargd real image of the specimen and shines it on the ocular lens.

When you adjust the focusing knob, you change the distace between this lens and the specimen; this means you can only look at one level of focus. The other levels may make the image look blurry.

A measure of the ability of a microscope defined by the minimum distance between two points where they can still be defined as separate points.

d = (0.61λ) / (n * sin α)

d = resolving power

λ = wavelength of light

n = refractive index of the medium present between the specimen and the objective lens

α = half the angle of the cone of light entering the objective lens. Related to numerical aperture.

A measure of the light-gathering ablities of a lens. Defined by the denominator of the equation for resolving power. The number will be on the side of the lens.

n * sin α

In air the highest possible value is 1. The sine of 90º is 1, and the refractive index of air is 1.

You can get higher NA by using lenses with a short focal length, meaning the lens is very close to the specimen.

The maximum useful magnifiction of a conventional light microscope is between 500 and 1000 times the NA of the objective lens.

A measure for a microscope found by substituting into the equation for resolving power the minimum possible wavelength and the highest possible NA.

A conventional microscope will get a value slightly less than 0.2μm. This is sufficient to see large cell organelles such as nuclei and mitochondria. The human eye gets around 0.1 mm. 

Optical flaws that occur when using a light microscope. They make it impossible to reach the theoretical levels of magnification or resolution.

In order to minimize aberrations objective lenses are made of a series of lenses. The first one magnifies the image, and the rest compensate for errors.

A molecule featuring a chromophore (usually an aromatic ring) that absorbs part of a spectrum, making it appear colourful. It is added to a specimen to stain it and give it some contrast when using a light microscope to view it. Some dyes will only stain certain biological molecules, giving another dimension of information to the image. pH is a factor in what molecules a dye may stain. Basic dyes stain by chemical absorbtion. Acidic dyes stain by infiltration and may wash out.

The problem with dyes is that they may be toxic to cells; you can only observe dead cells using them. Some stains cannot penetrate the plasma membrane, so they must be hydrolyzed in acid first, which kills them.

A chemical used in the processing of tissues before making a section. It rapidly immobilizes all macromolecular material in the tissue, maintaining cell structure.

Includes formaldehyde, alcohol, and acetic acids.

Afterwards the specimen is embedded in paraffin wax to provide mechanical support during sectioning. The wax may be dissolved away afterwards using toluene.

A type of light interference microscope that makes translucent objects more visible. It does this by converting differences in refractive index into differences in light intensity by first separating the light then making them interfere with each other.

Good for looking at intracellular components of living cells. Motility of organelles may be observed.

They have a handicap in terms of resolution. Images suffer from halos an shading where there are sharp changes in refractive inde.

A 238 amino acid, barrel-shaped protein that glows green by reflecting ultraviolet radiation in the form of visible light. It is resistant to denaturation. It is found naturally in Aequorea victoria jellyfish. It may be encorporated into the genes of other animals. It can be used to study the dynamics of proteins in living cells by combining this protein with the protein being studied. The chimeric protein functions in the cell normally, but glowing.

There are other varieties of glowing proteins in different colours including BFP (blue), YFP (yellow), and CFP (cyan).

May be used to look at large amounts of data such as hundreds of microscope readings or DNA sequences. It finds patterns or specific genes much quicker and with more accuracy than any human could. Also, this would be a very tedious job for a human.

It can also remove blurry background in images, or change differences in brightness into differences in colour, making an image easier to read.

They may take a series of 2D images to create a 3D model.

A type of video camera that is very sensitive to light, allowing it to film specimens at very low illumination.

This is good for observing living specimens, which may be damaged by excessive light. Also good for looking at fluorescently stained specimens. It can pick up tiny details that a human eye would not pick up. The images are easily transfered into digital images to feed to a computer.

A microscope that uses electrons passing through a specimen to form an image. It is a large hollow tube with a vacuum in it through which electrons are accelerated through a specimen at the bottom. The electron rays are focused by electromagnetic lenses. A single objective lens magnifies the image. They can achieve a resolution power many times greater than that of a light microscope. Resolution can be adjusted by the speed of the electrons, using voltage.

λ = √(150/V)

λ = wavelength in Å

V = voltage in volts

They may operate between 10,000 and 100,000 volts. eeven at low power the resolution is theoretically 0.03 Å. In reality aberrations make it 3 to 5 Å, which is still better than a light microscope.

Electrons only bounce off of heavy metals, so specimens must be stained with a heavy metal, which may form an artifact. Fixatives used are glutaraldehyde and osmium tetroxide, which react with amino groups and lipids respectively. The specimens are cut extremely thin (0.1μm max) by a machine. Uranyl acetate, lead citrate, or metal-tagged antibodies. 

Other fixation techniques include cyrofixation or freeze-fracture replicaton.

A microscope which uses electrons that have bounced off of the specimen. Electrons are accelerated at the specimen as a fine beam. They bounce of the specimen and hit a detector which forms the image. This gives information on the topography of the surface of the specimen. May be used for objects as small as bacteriophages and as big as animals (mostly bugs).

The specimen cannot have any fluids in order to be scanned. This limits the kinds of specimens that can be looked at. Critical-point drying is used to dry the specimen.

It can magnify from 15 to 150,000 times. Resolving power can be as small as 5μm. The depth of focus is 500 times that of a light microscope. 

A fixation technique for TEM specimens. The specimen is rapidly frozen. This way they don't have to use chemicals or be embedded in resins. This avoids the formation of artifacts, however ice crystals can form unless the water is vitrified properly.

Small specimens are plunged into very cold liquids such as liquid propane. Large specimens undergo high-pressure freezing with jets of liquid nitrogen. The high presure reduces the freezing point of water and thus the formation of ice crystals.

This method of fixation is used by pathologists.

A fixation technique used for TEMs where a specimen is flash-frozen then split with a knife. The crack goes through a cell, revealing inner structure. A heavy metal is applied to the open crack and a replica is made of the specimen using carbon.

Good for looking at membrane structures; the crack will always follow the path of least resistance, revealing membranes.

A high resoltion scanning instrument where a physical tip scans and object. It oscillates and "feels" variations in topography of the specimen. The information is then turned via computer into a 3D model of the surface of the specimen.

It can determine the exact molecule in the field, where other methods can only determine the average molecule. It may be used to test the mechanical properties of molecules. Ligands may be attached to the tip to test for a substances affinity to the ligand.

A stain that does not kill the cells it stains. Used for micro-organisms or tumour cells which may be cultured for a long period.

Trypan blue, propidium iodine.

A photoconvertible protein which changes fluorescence from red to green based on the wavelength of light it is exposed to.

Used to track individual cells/structures in a larger system.

It is stable, flexible, and capable of self-assembly. It is 6 nm thick. It is a lipid bilayer of amphipathic lipids with hydrophilic heads on the outside and hydrophobic tails on the inside. If you drop pure amphipathic lipids in water, small, empty liposomes of water will form. Each leaflet has a unique composition of lipids and proteins.

A cell membrane encloses the cell and all its compartments, controls movement in and out of the cell, detects external stimuli, and interacts with neigbhoring cells. Different membranes feature different proteins for their different functions.

They cannot form spontaneously, they are only expanded by inserting lipids and proteins.

The outer membrane of a cell. It is 5 to 10 nm thick. Discovered in the 1950s when it was successfully dyed. Under a microscope it appears to have 3 layers: two outer darkly dyed layers and one inner lightly dyed layer.

It is supported by a skeleton made from spectrin, ankyrin, and actin. The cytosolic layer has high levels of PI(4,5)P₂. This helps recruit proteins for clathrin-coated vesicle formation.

A model which says that a biological membrane has proteins stuck in it and they can move about laterally on the membrane and interact with each other freely.

The concentration and type of proteins is different based on the type of membrane it is.

Proteins that penetrate the cell membrane all the way through; they have components on each side of the membrane.

Produced co-translationally into the ER membrane. The translocon opens to the side to let it out into the membrane. Proteins with multiple trans-membrane segments are strung through like a sewing machine. The polypeptide sticks to the translocon in a way to correctly orientate it in the membrane. The N-terminus may be inside or outside of the lumen.

Proteins attached in some way to a biological membrane. Different cells and structures vary in the amount and representation of proteins. Feature meets form.

Most can move laterally along their leaflet, but to flip to the other leaflet requires an enzyme.

A sequence of hydrophobic amino acids on a protein up to 20 amino acids long which acts as an "address" in a postal system; it tells the protein where it is meant to go. Each organelle has an address and proteins may be sent to it.

It may be on either end of a protein.

During protin synthesis this sequence is made first (on the amino terminus) and directs the ribosome if and where to attach to the RER.

A bilayer of amphipathic phospholipids with the hydrophobic tails facing inwards and hydrophobic heads facing outwards. Continuous, unbroken sheets. The plasma membrane is one. It serves to compartmentalize eukaryotic cells into organelles, keeping chemical reactions from occuring between substances on either side of it, and encouraging chemical reactions of substances on same sides.

It is selectively permeable. Prevents unrestricted exchange but allows some exchanges.

A highly unsaturted omega-3 fatty acid found in fish oil which has supposed health benefits. It has 5 double bonds.

May be in the fatty acids of PE or PC in the brain or retina.

A highly unsaturate fatty acid found in fish oil with supposed health benefits. It has 6 double bonds.

May be in the fatty acids of PE and PC in the brain and retina.

A short incubtion period of a cell in a radioactive isotope (pulse) followed by viewing with a  microscope (chase). Only some of the proteins are marked, allowing to track particular substances through the cell.

This was abandoned in 1994 when the use of fluorescent proteins came about. Radioactive substances are dangerous.

A family of oxygen-transferring enzyme found in the SER which can detoxify many different compounds. They lack substrate specificity. 

Black charr on cooked meat turns carcinogenic when oxidized.

It is found in many medications. Genetic differences in naturual detoxification is why some people react differently to medication than others.

When incorrect proteins are produced at a rate which the proteasomes cannot handle, a series of signals result in the production of more chaperones, transport proteins, and protein destroying proteins. Key amino acids are phosphorylated to prevent any more incorrect proteins from forming. 

It can lead to the death of the cell. When the cell recieves suicide signals, it may undergo this even if there are no incorrect proteins.

A model for how the Golgi complex moves. This model was accepted until the 1980s when it was challenged by the vesicular transport model. It is now accepted again.

Each cisternae matures into the next one, moving away from the ER. Resident proteins are brought back to the right cisternae by vesicles. Blocking vesicle flow from the ER causes it to desintigrate. The fact that some cisternae have certain proteins is due to retrograde motion.

A vesicle with soluble proteins accumulted on its outer surface. It may have just recently budded. The protein coat aids the vesicle in the budding process: it shapes the bud as well as selecting specific cargo. The coat has two layers: an outer cage and an inner layer of adaptors.

There are COPII, COPI, and Clathrin coats.

"Coat protein 2". They move materials from the ER in anterograde motion to the ERGIC and Golgi, and from cis to trans Golgi cisternae. The proteins in the coat recognize proteins labelled with "ER export" in their cytosolic tails. Docking proteins and cargo-binding proteins are recruited.

Sar1, Sec 13, Sec23, Sec24, and Sec 31 help in forming the budding shape.

Adaptor

An inherited disease caused by the mutation of the peroxisomal enzyme ABCD1. Lorenzo's Oil was about a boy with this disease. Boys with this disease are unaffected until mid-childhood, when they get the symptoms of adrenal insufficincy and neurological dysfunction. VLCFAs accumulate in the brain, damaging myelin sheaths.

It can be treated with bone marrow transplant, providing normal cells to metabolize VLCFAs. Lovastatin can also be administered to lower VLCFA levels. Gene transplant may be used to cure it.

The membrane-bound digestive organelle in cells. They are absent in plants. They are diverse in size and structure. They have a role in organelle turnover.

They contain over 50 different hydrolytic enzymes, which are produced in the RER. They can hydrolyze virtually any bological macromolecule. The enzymes are acid hydrolases with low optimum pHs; the pH is around 4.6. This acidity is maintained by V-type H⁺-ATPase. The interior surface of the organelle's membrane is very glycosylated to protect itself from being digested.

The cells in mammals which scavenge the body and ingest dead or damaged cells, debris and potentially harmfull micro-organisms. Machrophges, neutrophils. They digest their findings in lysosomes; the low pH kills the micro-organisms. The engulfment of large materials is driven by contractile activities of actin microfilaments.

If an intruder is detected it notifies the immune system via proteins on the plasma membrane.

"Self eating". The destruction of a cell's own organelles. The organelle is surrounded by a phagophore, producing an autophagosome, which then fuses with a lysosome to form an autolysosome, digesting the organelle and reusing its components. A healthy liver cell will recycle 1 to 1.5% of its proteins every hour. It is slective; only specific organelles are destroyed. It protects the cell from abnormal protein aggregates and invasive bacteria or parasites. It is especially important in brain and nerve cells.

It evolved as a response to nutrient deprivation; it is increased in cells under starvation conditions; energy required for life is taken from the cell itself. This is seen in mammal embryos prior to planting in the uterus wall.

The membrane that binds the vacuole of plant cells. It has active transport proteins that pump in ions. Water then fills the vacuole by osmosis, puffing it up and giving the cell mechanical support from turgor pressure.

It has a network of tubules on its outer side which act as fusion platforms.

A phospholipid. It has 7 different types based on where the phosphate group is added on the sugar ring: PI(3)P, PI(4)P, PI(5)P, PI(3,4)P₂, PI(4,5)P₂, PI(3,5)P₂, and PI(3,4,5)P₃. These are recognized by proteins, giving the membrane an identity, playing a role in endocytosis.

PI(3)P means early endosomes. PI(3,5)P₂ means late endosomes. PI(4)P means the TGN and secretory granules/vesicles.

Receptors wchich uptake ligands that carry messages and change activities in the cell. They bind to insuling, hormones, or growth factors such as EGF and trigger physiologic responses in the cell. The receptor is destroyed in receptor-down regulation.

When inside the endosome, it is bound into small vesicles inside its lumen by ESCRT complexes.