{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

BIOL125_Ch4 Text Notes

BIOL125_Ch4 Text Notes - BIOL 125(Microbiology Text Notes...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
BIOL 125 (Microbiology) Text Notes Chapter 4: Survey of Prokaryotic Cells and Microorganisms 1. CHARACTERISTICS OF CELLS AND LIFE a. All cells tend to be spherical, cubical, or cylindrical; and the cytoplasm is surrounded by a cell membrane. b. Most cells fall into one of two fundamental different lines: prokaryotic cells and eukaryotic cells. i. Eukaryotic cells are found in animals, plants, fungi, and protists. They contain complex organelles, which are enclosed by membranes, and carryout specific activities involving metabolism, nutrition, and synthesis. ii. Prokaryotic cells are found only in the bacteria and Archaea. They have no nucleus or other organelles. c. What is Life? i. The characteristics most inherent to life are: 1) Heredity and reproduction. 2) Growth and development. 3) Metabolism, including cell synthesis and the release of energy. 4) Movement and/or irritability. 5) Cell support, protection, and storage mechanisms. 6) Capacity to transport substances into and out of the cell. ii. Heredity and Reproduction. 1) Hereditary material of an organism lies in its genome (a complete set of genetic information). a) The genome is composed of elongated strands of DNA packed in to chromosomes. i) In eukaryotic cells, the chromosomes are located within a nuclear membrane. They also carry a different type of chromosome within their mitochondria. ii) In prokaryotic cells, the DNA occurs on a special type of chromosome not enclosed by a membrane. 2) Most eukaryotic cells reproduce both sexually and asexually. a) Many eukaryotic cells engage in mitosis , an orderly division of chromosomes that usually accompanies cell division. 3) Prokaryotic cells reproduce primarily by binary fission , a process of cell splitting equally into two. They have no mitotic apparatus, nor do they reproduce sexually. File: 80306990c7aabdeb08e16b47872689642404d3ef.doc Updated 8/14/09
Background image of page 1

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

View Full Document Right Arrow Icon
Text Notes Chapter 4 Page 2 iii. Metabolism: Chemical and Physical Life Processes. 1) Cells synthesize proteins using ribosomes. a) In eukaryotes, ribosomes are dispersed throughout the cell or inserted into membranous sacs called endoplasmic reticulum (ER) . b) Prokaryotes have smaller ribosomes scattered throughout the cytoplasm because they do not have an ER. 2) Eukaryotes generate energy by chemical reactions in the mitochondria. a) Photosynthetic eukaryotes contain chloroplasts, which contain the pigment for photosynthetic reactions. 3) Prokaryotes use the cell membrane to generate energy. a) Photosynthetic reactions in prokaryotes occurs in the cell membrane, not in chloroplasts. iv. Movement and Irritability. 1) Motility – self-propulsion. a) Eukaryotes move by locomotor organelles such as cilia, flagella, or pseudopods. b) Motile prokaryotes move by flagella unique to bacteria or by special fibrils that produce a gliding from of motility. They have no cilia or pseudopods.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 13

BIOL125_Ch4 Text Notes - BIOL 125(Microbiology Text Notes...

This preview shows document pages 1 - 3. Sign up to view the full document.

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