Cell components 1

Cell components 1

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hello guys in this presentation we are going to talk about the different components that make up a normal human set obviously not all human cells are the same so that means that a certain cells will have specific organelles that won't appear in other types of cells and risers okay we have already reviewed the names of the different components of a cell in these two pictures okay this is a micrograph taken with a transmission electron microscope
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a very powerful microscope and this is just a drawing an image that someone has made so i'm going to show you both contrasting real pictures and man-made picture pictures okay so let's get started all cells have a basic structure that is made up of three components this refers to all cells that means even prokaryotic cells
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these three things are the cell membrane the cytoplasm in which organelles are contained and genetic material in the form of dna both prokaryotic and eukaryotic cells have these components in the case of human cells because they are eukaryotic cells the dna is enclosed inside a membranous structure that we call the nucleus and in the cytoplasm we find a great variety of different organelles
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made by membranes okay prokaryotic cells are much simpler they do not have a nucleus and the range of organelles they can have is very small so let's examine all the different organelles that we can find in a human set the first component is the cell membrane the cell membrane is a thin and flexible layer that represents the outer limit of the cell it is made of lipids in this case the
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orange and blue part a little bit proteins that are represented in different colors here and carbohydrates normally simple carbohydrates or glucites the lipids form uh by layer because we have two layers one here and one here okay and these lipids have the capacity to show a semi-fluid con behavior meaning that they can um
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[Music] undergo different movements and be kind of flexible okay proteins sometimes appear on one or the other side but sometimes form a transmembrane channels that allow the entrance or excess of different particles and substances and carbohydrates only appear in the outside of the membrane because they act as receptors or cyclin
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molecules well the cytoplasm would be the inside of the cell all the space that is contained inside the plasma membrane or cell membrane it is filled with a gel like fluid that we call the cytosol the cytosol is basically made of water but it contains many substances dissolved like for example glucose it can contain vitamins it can contain
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rna and other different structures it is also the medium where organelles are embedded or floating okay and in it many chemical reactions take place okay so it's an important component of the cell let's continue with the nucleus the nucleus is a membranous structure that encloses dna obviously it only exists in eukaryotic cells the nucleus has an external
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envelope that we call the nuclear envelope okay it's here and this has the characteristic to be a double membrane okay so it has an inner layer of lipids and an outside layer of liquid without a space in between it's also um well it also contains pores like these ones that you have that allow the exchange of certain
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molecules or particles between the inside and the outside of the nucleus inside the nucleus we have the dna but dna in eukaryotic cells is combined with proteins forming a substance that we call chromatin okay so it's not only the enable chromatin a mixture of dna and proteins this chromatin appears as a granular and a more false mass inside the nucleus
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when the cell is not dividing okay and in it we can distinguish a darker spot that we call the nucleolus okay nucleolus when the cell is dividing such as in this picture in this picture we have a cell that is dividing the chromatin is more condensed or compact so it forms individual thick fragments like the ones you can see here that are called chromosomes each
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chromosome is a molecule of dna combined with proteins and compacted at the maximum level okay so here in this picture you can see how inside the nucleus we have this amorphous mass of dna with proteins like chromatin uh but this mass can be compacted even more thanks to the proteins okay forming the chromosomes this is a typical shape
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of a chromosome although it cannot be appreciated very well in the picture okay so each of these would be a chromosome when the cell is not dividing remember the chromatin would appear as an amorphous mass and the nucleolus would be visible such as in this other set well let's talk a little bit about the genetic information in a human cell the function of dna is to contain the information that a cell needs
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to perform all vital functions that it does basically to synthesize all the substances and proteins that it's going to need this information is also hereditary inflammation meaning that a parents transmit dna to their children okay so this informative and hereditary molecule dna together with proteins from the chromatin
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and when condensed it forms chromosomes this is the typical genetic makeup of a human being okay and each of these things would be a chromosome as you can see human beings always have 23 pairs of chromosomes for a total of 46. we normally organize them in pairs because each chromosome in a pair comes from one
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parent one from the mother and one from the father and both chromosomes in a pair contain the same kind of inflammation but given from a different progenitor okay all of these 23 pairs 22 are considered to be autosomes meaning that they are the same in women and men okay they do not show differences between sexes the last pair is also called
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heterochromosomes or sex chromosomes and they are different in men and females okay while men have two different chromosomes called x and y a woman has two equal or similar chromosomes that are two x chromosomes so we say that men are x y while female are x x okay well
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a gametes only have have the number of chromosomes so instead of having 23 pairs of chromosomes they have only 23 chromosomes so that when gametes join in fertilization during sexual reproduction the zygote or the resulting cell will have again 20 pairs of chromosomes okay is this clear well so let's continue then talking about other organelles that are
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very important for cells so first of all mitochondria all human cells have mitochondria mitochondria are very important for cells because they are the power plants meaning that they are the ones that obtain energy from nutrients okay especially simple carbohydrates such as glucose but also other nutrients um let's describe the structure of a mitochondria a mitochondria is an elongated organelle
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that has a double membrane being the outside membrane the one in red here smooth that causes the in the the entire surface and the inner membrane here in yellow is deeply folded forming kind of a crystal okay inside sorry in between them there is a space okay the inter membrane spray is space that is also important for the
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a task mitochondria perform inside the two membranes there is a space that we call the matrix in which we can find different things such as small molecules of dna ribosomes certain granules of proteins and other things etcetera okay the main function of mitochondria well here you have a real picture from a transmission electron microscope with the crystal and the double membrane outside and the main function is to do cell
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respiration cell respiration is a process by which mitochondria consume nutrients mainly glucose and they burn up these nutrients with oxygen to produce energy the energy is stored in a molecule that we call atp adp is like a coin that stores the energy and can be used at different moments by the same as byproducts cell respiration
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also produces carbon dioxide and water vapor that are expelled more organelles that we can find in a human cell well we have ribosomes as well ribosomes are called a protein factory because that's their function to synthesize to make proteins by using the information contained in dna ribosomes are very very small structures that cannot be seen under the most powerful light microscope so only with electron microscopes we can see
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the ribosomes a little bit this is a very very magnified image okay a close-up view of my l ribosomes here we have them smaller okay ribosomes consist of two subunits a big or large subunit and a small subunit that are together okay to form the ribosome ribosomes appear free in the cytoplasm they can also appear attached to the endoplasmic reticulum in the graph in the plasmid reticulum
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such as in here as we recommend and also attach to the nuclei membrane some ribosomes can also be present inside mitochondria okay well the endoplasmic reticulum the endoplasmic reticulum is a network of interconnected sacs and tubes like in here that is used to produce different substances especially proteins in the case of the rough endoplasmic reticulum
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the raw endoplasmic reticulum is called like that because it contains ribosomes ribosomes produce proteins and proteins pass into the the cisterna space or the sacs that make up the endoplasmic reticulum to be modified smooth endoplasmic reticulum however produces carbohydrates and some kinds of lipids okay the rough endoplasmic reticulum is connected to the nuclear envelope and the whole structure surrounds it
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here you have real pictures of it and you can see this is the rough in the plasmid reticulum you see the flat sacs with little dots that are ribosomes attached to the membrane and also this is the aspect that we can get from the smooth endoplasmic reticulum if we call it under a microscope because we would see the section the cross-section of these tubes okay so these circles would be these circles here well uh i will stop here
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and produce a new video to continue with the rest of the ordinance so please pay attention and complete your tables now

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