Question | Answer |
Kinds of cells | Eukaryotes prokaryotes |
DNA in Prokaryotes | DNA is not enclosed in nuclear membrane, one circular chromosome, not associated in with histones |
Prokaryotic Cells | no membrane enclosed organelles |
DNA Eukaryotes | DNA encolsed in nuclear membrane, multiple chromosomes, associated w/ histones and non histones |
Eukaryotic cells | golgi complex, mitochondria, lysosomes |
Prokaryotes | include bacteria and archaea |
Species of Bacteria are Differeniated by | Morphology, chemocal composition, nutritional requirements, biochemical activities, source of energy |
Basic Shapes | Bacillus, cocci, spiral, |
Bacillus | Rod shape |
Coccus | spherical |
Spiral | Spirillum, Vibrio(comma shaped), spirochetes |
Sarcinae | Coccus- remain in groups of 8 |
Streptococci | remain attached in chainlike pattern |
Staphylococci | fomr grapelike structures |
Spirochetes | helical and flexible |
Unsual bacterial shapes | stella and haloarcula |
Shape determination | heredity |
Monomorphic | maintain a single shape |
Pleomorphic | can have more than one gentically controlles shape |
Pleomorphic bacteria | Rhizobium, corynebacterium |
Prokaryotic cell layers | outer membrane, cell wall, capsule, plasma membrane, nucleoid region, ribosomes, pilus, flagellum |
Glycocalyx | Sugar coat on surface of many cells, made inside and secreted outside |
Capsule | organized and firmly attached glycocalyx |
Slime layer | unorganized and loosly attached glycocalyx |
Purpose of capsule | provides protection against phagocytosis, allow bacteria to attach to surfaces, source of nutrition, protects from dehydration |
Flagella | Motility |
Arrangements of flagella | monotrichous, amphitrichous, lophotrichous, peritrichous |
Monotrichous | single polar flagellum |
amphitrichous | tuft of flagella on both ends |
lophotrichous | 2 or more flagella at one pole |
peritrichous | flagella distributed all over cell |
Parts of flagella | Filament, hook, basal body |
Filament | long outermost part, constant diameter, composed of flagellin |
flagellin | globular protein, arranged in intertwining chains, forming,helix, around hollow core |
Hook | filament attached to it, wider, made of different protein |
basal body | small central rod inserted into a series of rings |
gram negative basal body | outer ring anchored to various portions of cells; inner ring attachedto plasma membrane |
gram positive basal body | one pair of rings, only one paired attached to plasma membrane |
Run | flagella movement is in one direction |
tumbles | abrupt random changes in direction |
taxis | movement torward or awayfrom a stimulus |
Positive Taxis | movement torward an attractant |
Negative Taxis | movement away from repellent |
Axial Filament location | Found on spriochetes and also called endoflagella |
Axial filament | made of bundles of fibrils beneath an outer sheath and spiral around cell |
Fimbrae & Pili | found in gm neg bacteria, shorter and thinner than flagella |
composition of fimbrae & Pili | made of protein called pilin |
Fimbrae | enables a cell to adhere to surfaces, if not present no colonizationa |
Pili | Sex Pili, 1 or 2 found on cells; join cells for transfer of DNA from one cell to another |
the cell wall | point of anchorage for flagella |
pseudomurein | archaea cell wall - modification of muramic acid |
Peptidoglycan composed of | NAG and NAM which make carbohydrate backbone |
rows are linked by | polypeptides that always include tetrapeptide side chains of 4 amino acids attached to NAM |
Penicillin | interferes with final linking of peptidoglycan rowsby peptide crossing bridge |
Gram positve cell wall | many layers of PTG, contain techoic acid(Lipo/Wall) |
Lipotechoic | Linked to plasma membrane |
wall techoic | linked to PTG |
Gram Negative cell wall | one or few layers of peptidoglycans, no techoic acid |
PTG | present in periplasm |
Lipid A | endotoxin causes fever and shock |
O Polysaccahride | is antigenic and ised for ID |
lysozymes | target cell wall- cuts the bond btwn sugars |
protoplasts | help rebuild cell wall |
Osmotic lysis | Destruction of protoplast and spheroplasts |
Passive process | substance moves from higher concentration to lower concentration w/o energy |
Active process | substance moves from area of lower concentration to higher concentration w/ energy |
hypotonic solution | cell with weak cell wall may burst |
hypertonic | bacterial cells shrink and collapse |
group translocation | only prokaryotes- special type of active transport |
Group translocation energy | Phosphoenol Pyruvic Acid (PEP) |
Plasmids | small circular double stranded DNA which are extra- chromosomal- carry genes for abx resistance. |
70S | prokaryotic ribosomes composed of 50S and 30S |
50S | large subunit attacked by erythromycin and cloramphenicol |
30S | smaller subunit attacked by mycin's |