The nucleolus (plural nucleoli) is a non-membrane bound structure. Composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA (rRNA) is transcribed and assembled within the nucleolus. Three major components of the nucleolus are recognized: the fibrillar centers (FC)‚ the dense fibrillar components (DFC)‚ and granular components (GC). The DFC consists of newly transcribed rRNA bound to ribosomal proteins‚ while the GC‚ contains rRNA bound to ribosomal proteins that are beginning
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control as exchange Main function of stomata : Allow enough C02 to enter the leaf to optimize photosynthesis‚ while conserving as much water as possible Structure of stomata * Each stomata consists of a stoma (minute pore) which are surrounded by 2 guard cells. * Stomata closes and opens according to the turgidity of the guard cells * Stomata also allows for cooling of the leaf by loss of water through transpiration to lower leaf temperature * Guard cells open and close to control
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Micrometre Millimetre 5 0.005 0.000005 1 1 1 3 7 0.5 3) When studying cells structure using a microscope the smallest unit of measurement commonly used to describe findings is the nanometre. Explain why. Magnification and Resolution 1) Define the following terms: Magnification: Resolution: 2) Visible light has a wavelength of 400-700 nm. Calculate the best resolution achievable with a light microscope? Show your working out: 3) If the electron gun produces an electron beam
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MEMBRANE PROTEINS determine the membrane’s function Many diff. types of protein in plasma membrane 2 types of proteins Peripheral proteins-loosely bound to surface‚ not embedded in bilayer Integral proteins-penetrate the hydrophobic core Integral Proteins Transmembrane proteins=integral proteins that span the membrane The hydrophobic regions of an integral protein consists of one or more sections of non-polar amino acids‚ often coiled in alpha functions of membrane proteins Transport Allow
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1.1 Studying the Structure of Cells In 1665‚ English scientist Robert Hooke became the first person to study cells Cell Structure Nucleolus: Makes Ribosomes‚ which help to make proteins Nuclear Membrane: Protects the contents of the nucleus Nuclear Pores: Allow materials‚ such as ribosomes‚ in and out of the nucleus |Light Microscope |Electron Microscope | |Uses light source |Beams of electrons
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Whether you are already an experienced practitioner in other complementary or beauty therapies or this is you first course‚ I am sure that you will embrace what you learn from this course and finish it feeling motivated and humble that you can provide this wonderful treatment to your clients‚ family and friends. Facials and skin exfoliation are an important part of general skin maintenance. Facials include deep cleansing‚ exfoliation‚ moisturizing‚ mask application‚ and massage‚ are great for removing
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CHAPTER 1 Cell Structure and Organisation Cells * All living organisms are made up of cells * The simplest living organisms have one cell only * His name is unicellular-e.g. bacteria. * Most other living organisms have many cells- his name is multicellular- e.g. Man‚ plants‚ animals. * Cells can be seen only under microscope Cell structure All cells have the following structure in common: a) Cell membrane- a very thin layer of protein and fat‚ surrounding the cell. It is
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DNA STRUCTURE AND FUNCTION QUIZ Provide answers to each of the following. You may consult your text and fellow students. Each numbered item counts 2 points. 1. If one strand of a DNA double helix has the sequence GTCCAT‚ what is the sequence of the other strand? a. ACTTGC b. CUGGTU c. CAGGTA d. CAGGUA e. TGAACG 2. If a strand of DNA has the sequence AAGCTC‚ transcription will result in a(n) ______. a. single DNA strand with the sequence TTCGAG
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The cells of the adaptive immune system are special types of leukocytes‚ called lymphocytes. There are two main types of lymphocytes‚ B cells and T cells‚ which are derived from hematopoietic stem cells in the bone marrow. T cells are involved in cell-mediated immune response‚ whereas B cells are involved in the humoral immune response. The surface of each lymphatic cell has receptors that enable them to recognize foreign substances. There are two major subtypes of T cells: the helper T cell and
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Bacterial cells are Prokaryotic cells. These cells have several internal structures and surface structures. The cell walls are of two types‚ gram positive and gram negative. Out of all the structures‚ the two selected structures are the cell- wall and endospores. The cell- wall of bacterial cells is found in three distinct shapes such as spherical‚ spiral and rod shaped. The cell wall of the bacterial cells is composed of the proteins and polysaccharides. This is collectively called peptidoglycan
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