Biology_1202_Exam_2

Biology_1202_Exam_2 - Biology 1202 Notes Exam 2 Chapter 27:...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Biology 1202 Notes Exam 2 Chapter 27: Prokaryotes One thing that E. Coli and other bacteria have in common with eukaryotes is the presence of____ o Chloroplasts o Mitochondria o Nucleus o Ribosomes Structural, functional, and genetic adaptations contribute to prokaryotic success. o Prokaryotes are unicellular. Some colonial forms. o Range in size from 1-5 m. Thiomargarita namibiensis (750 m) o No membrane-bound organelles. o Circular chromosomes while eukaryotes have linear chromosomes . Prokaryotic Domains o Comparison of traits found in the Domains Bacteria, Archaea, and Eukarya. o Know differences between Bacteria and Archaea Prokaryotic cells have a variety of shapes. o The three most of common are spheres (cocci), rods (bacilli), and spirals (spirilli). Cell Surface Structures o Cell wall Maintains cell shape, provides physical protection, prevents cell from bursting in a hypotonic environment. Composed of peptidoglycan . May also have an outer phospholipid membrane. Gram positive contains purple under the microscope, while gram negative is red, which consists of an inner plasma membrane, peptidoglycan, and an outer membrane. Gram positive are bacilli and gram negative are cocci. o A capsule (a sticky layer of polysaccharide or protein) may cover the cell wall of many prokaryotes. o Fimbriae and pilli allow prokaryotes to stick to their substrate or other individuals in a colony. Motility o Motile bacteria move by means of a flagella . Structurally different from eukaryotic flagella. o In a heterogeneous environment, bacteria exhibit taxis (ability to move toward or away from certain stimuli). I nternal Organization o Prokaryotes do not have membrane-bound organelles. o Some do have specialized membranes that perform metabolic functions. Genomic Organization o Prokaryotic chromosome (circular DNA found in the nucleoid region) false nucleus. Not within a nucleus o Plasmid- (smaller circular DNA rings). Additional genes not always necessary for basic survival. E.g., antibiotic resistance. Reproduction o Prokaryotes reproduce quickly by Binary fission . Can divide every 1-3 hours. o Form of asexual reproduction Produces genetically identical daughter cells . o Bacterial conjugation Transfer of genetic material between two bacteria. Not necessarily the same species ( Horizontal gene transfer ) Plasmids are usually transmitted from donor through a sex pilus . Groups of staphylococci look like_____ Corkscrews Filaments Rods Clusters of grapes A great diversity of nutritional and metabolic adaptations has evolved in prokaryotes. o Different types of metabolism Phototrophs- organisms that obtain energy from light....
View Full Document

This note was uploaded on 03/31/2010 for the course BIOL 1202 taught by Professor Gregg during the Spring '08 term at LSU.

Page1 / 30

Biology_1202_Exam_2 - Biology 1202 Notes Exam 2 Chapter 27:...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online