ll animals and plants are made of cells. Animal and plant cells have features in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells also have a cell wall, and often have chloroplasts and a permanent vacuole. Note that cells may be specialised to carry out a particular function.
We use microscopes to see very tiny structures such as cells.
Bacterial cell structure
Bacterial cells are much smaller than plant or animal cells. They were first seen under a microscope by Anton van Leeuwenhoek in 1676. As microscopes have improved, scientists have come to understand bacterial cell structure better.
Using electron microscopes we now know that bacteria have a cell wall. This is similar to a plant cell wall but is more flexible. Bacteria do not have a nucleus. They do have two types of DNA – plasmid and chromosomal. The chromosomal DNA carries most of the genetic information. Plasmid DNA forms small loops and carries extra information. Some bacteria have a flagellum – a whip like tail. This helps the bacteria to move itself along. When we talk about these flagellum tails in multiple bacteria, we call them flagella.
arly microscopes did not magnify to a great extent and scientists have worked hard to improve this. We now have modern light microscopes that can magnify 1,500 times and electron microscopes that can magnify up to two million times. This has allowed scientists to see things such as cells in much greater detail. As a result
animal or bacterial cell, they spring into action. They infect and take over the cell like pirates hijacking a ship, A virus is basically a tiny bundle of genetic material either DNA or RNA carried in a shell called the viral coat, or capsid, which is made up of bits of protein called capsomeres. Some viruses have an additional layer around this coat called an envelope. That's basically all there is to viruses. When viruses come into contact with host cells, they trigger the cells to engulf them…
Can be distinguished by the shape of their cells, and the colonies they form ∙ Spirochete (spiral) ∙ Bacillus (rodshape) Capsule a sticky layer that surrounds the cell walls of some prokaryotes, protecting the cell surface and sometimes helping to glue the cell to surfaces. Cell wall a protective layer external to the plasma membrane in plant cells, prokaryotes, fungi, and some protists. …
What is bacterial resistance? Well bacterial resistance is a bacteria’s ability to survive in the presence of a chemical agent, such as antibiotics or antimicrobials. I want to discuss how bacteria get there resistances, what the causes are, and how this will affect people. There are all types of different microorganisms that have some sort of resistance to antibiotics but how did they come to be resistant? This is one of the main questions that I want to answer. Are we responsible for the resistance…
Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured. Section Reference 1: Section 6.1 Growth and Cell Division 2) The type of cell reproduction in which a small, new cell develops from the surface of an existing cell and then separates from the parent cell is known as ________ and is the normal mode of replication in _____ . a) binary fission, bacteria b) binary fission, yeast c) budding, bacteria d) budding, yeast Answer:…
Approaches to studying bacterial host interactions What they really tell us www.inhabitat.com TABLE OF CONTENTS TABLE OF CONTENTS i 1 INTRODUCTION……………………………………………………………………………………………………………………………………1 2 HOST-BACTERIA INTERACTION……………………………………………………………………………………………………………1 2.1 BENEFICIAL AND NON BENEFICIAL RELATIONSHIP………………………………………………………………………….2 3 DEFENSE SYSTEM: HOST AND BACTERIA……………………………………………………………………………………………..2 3.1 HOST DEFENSE SYSTEM………………………………………………………………………………………………………………
Prokaryotic Cell Sources; http://hyperphysics.phy-astr.gsu.edu/hbase/biology/prokar.html http://biology.about.com/od/cellanatomy/ss/prokaryotes.htm http://en.wikipedia.org/wiki/Nucleoid http://www.biology-online.org/dictionary/Plasma_membrane Prokaryotic cells are cells that lack a membrane-bound nucleus. The Greek language connotes that the term prokaryotes mean ‘before nuclei’. Prokaryotic cells tend to have very few internal structures, which are distinguishable under the microscope. Cells that…
Objectives 1. Glycocalyx is a gelatinous, sticky substance that surrounds the outside of a cell. It may be composed of polysaccharides, polypeptides, or both. They form capsules or loose slime layers that protect cells from desiccation (drying). With regard to human health, the presence of a glycocalyx is a feature of numerous pathogenic bacteria and these glycocalyces play an important role in the ability of these cells both to survive and to cause disease. 2. The slime layer is loose and water-soluble…
Bacterial Transformation Lab Report I. Pre-lab Bacterial transformation occurs when an organism receives DNA from a different species and expresses the implemented gene, thus becoming a transgenic organism. The practice proceeds as follows: first cut the plasmid from one organism and DNA from another, using the same restriction enzyme on a palindromic sequence. The recombinant plasmids then enter the host bacteria and asexually reproduce infinitely. We can identify that the bacteria has the new…
Lab Exercise DNA Extraction 10/30/13 DNA in all organisms is found primarily in chromosomes. Eukaryotic cells, like those found in humans, contain several linear chromosomes. Prokaryotic cells, such as bacteria, contain one large circular chromosome. DNA is composed of building blocks called nucleotides, each made up of a five-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base. The four kinds of nucleotides differ only in their nitrogenous bases. It is…