Cell Organelles

Notes from ?O? Level BiologyCells Summary1.Cells contain living matter called protoplasm2.Protoplasm consists of 3 partsa)Nucleus ? controls the activities of the carrel and is responsible for electric cell reproductionb)Cytoplasm ? where or so of the cell activities recognise placec)Cell membrane ? controls subjects entering/leaving the cell3.Cells differ in surface and shape according to their function4.Cells group to put to scarper tissues, tissues group to devise harmoniums, organs function in organ systems and various organ systems that make up an organism. 5.Diffusion occurs when molecules of a substance move from a region of higher concent ration to a region of get down concentration of the substance (down a concentration gradient)6.Osmosis is a peculiar(a) kind of diffusion involving movement of urine molecules across the cell membrane to where they atomic number 18 in glower concentration. It supplies the plant with water7.Active expect occurs only in living cells winning up a substance against a concentration gradient8.The ratio of surface body politic to volume determines the rate at which substances will move into a cell. Membrane systems and organellesNucleus?Consists of nucleoplasm terpsichore by two membranes cognise as the atomic envelope, which has perforations called nuclear pores?Chromatin, found in the nucleoplasm, condenses to form chromosomes during cell region.

The denser areas of chromatin granule that are more darkly stain are called heterochromatin, and the remaining areas of chromatin are called euchromatin?Nucleolus (within the heart) is a spherical body replete in ri bosomal RNA?Functions of the nucleus:-To con! trol all cellular activity-To undergo nuclear division for cell replication to occur-Contain the DNA, necessity for inheritance-Produce ribosome?s (nucleolus)-Produce RNAEndoplasmic Reticulum (ER)? series of membranes creating channels within the cytoplasm?2 types of ER: earthy ER and smooth ER? some ER is continue with tiny granules easily seen with an negatron microscope. These are called ribosomes, and they play an all-important(a) role in the synthesis of proteins. Rough ER is most abundant in... If you want to get a full essay, orderliness it on our website: BestEssayCheap.com

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