AP Biology Chapter 27 Flashcards

ch 27 for ap bio (bacteria)

9220125158	peptidoglycan	A polymer composed of modified sugars cross-linked by short polypeptides. This molecular fabric encloses the entire bacterium and anchors other molecules that extend from its surface.	0
9220125159	Gram stain	A technique that allows scientists to categorize many bacterial species according to differences in cell wall composition.	1
9220125160	Gram-positive	These bacteria tend to have simpler walls with a relatively large amount of peptidoglycan.	2
9220125161	Gram-negative	These bacteria tend to have less peptidoglycan, are more structurally complex, with an outer membrane that contains lipopolysaccharides (carbohydrates bonded to lipids).	3
9220125162	capsule	A dense and well-defined sticky layer of polysaccharide or protein that surrounds the cell wall of many prokaryotes.	4
9220125163	fimbriae	hair-like appendages that allow prokaryotes to stick to their substrate or to one another.	5
9220125164	pili	Appendages that pull two cells together prior to DNA transfer from one cell to the other; tend to be longer and less numerous than fimbriae.	6
9220125165	nucleoid	A region of cytoplasm containing the prokaryote's genetic material; not enclosed by a membrane.	7
9220125166	plasmids	Smaller rings of independently replicating DNA molecules that only carry a few genes, found in prokaryotic cells, in addition to its single chromosome.	8
9220125167	transformation	The genotype and possibly phenotype of a prokaryotic cell are altered by the uptake of foreign DNA from its surroundings.	9
9220125168	transduction	Phages carry prokaryotic genes from one host cell to another.	10
9220125169	conjugation	DNA is transferred between two prokaryotic cells (usually of the same species) that are temporarily joined. In bacteria, the DNA transfer is always one-way: One cell donates the DNA, and the other receives it.	11