Section 6.2 Marine Biology

Marine Bacteria General characteristics simple, ________________ organization: no nuclei or membrane-bound organelles, few genes, nonliving cell wall reproduce asexually by binary fission many shapes and sizes _____________—rod shape _____________—spherical shape Example:

Figure 6-6 BACTERIA AND NUTRIENT CYCLING.

Nutritional Types _______________________ (blue-green bacteria) photosynthetic bacteria which are found in environments high in dissolved oxygen, and produce free oxygen store excess photosynthetic products as cyanophycean starch and oils primary photosynthetic pigments are chlorophyll a and chlorophyll b accessory pigments include carotenoids and phycobilins

(a) Cyanobacteria – Free oxygen produced Light energy Carbon dioxide (CO2) Water (H2O) Oxygen (O2) Carbohydrates (CH2O)x (a) Cyanobacteria – Free oxygen produced Light energy Hydrogen sulfide (H2S) Carbon dioxide (CO2) Sulfate (SO42–) Carbohydrates (CH2O)x (b) Purple and green bacteria – No free oxygen produced Stepped Art Fig. 6-8, p. 132

Nutritional Types (Cyanobacteria) Cyanobacteria (con’t) ________________ adaptation—response of pigment composition to the quality of light in the sea may exist as single cells or form dense mats held together by mucilage form associates called ___________________—a coral-like mound of microbes that trap sediment and precipitate minerals in shallow tropical seas

Nutritional Types Other photosynthetic bacteria ______________ green and purple sulfur and non-sulfur bacteria do not produce oxygen the primary photosynthetic pigments are bacteriochlorophylls sulfur bacteria are obligate anaerobes (tolerating no oxygen) non-sulfur bacteria are ___________________(respiring when in low oxygen or in the dark and photosynthesizing anaerobically when in the presence of light)

Figure 6-8 (b) BACTERIAL PHOTOSYNTHESIS.

Nutritional Types ___________________ bacteria use energy derived from chemical reactions that involve substances such as ammonium ion, sulfides and elemental sulfur, nitrites, hydrogen, and ferrous ion chemosynthesis is less _____________ than photosynthesis, so rates of cell growth and division are slower found around __________________vents and some shallower habitats where needed materials are available in abundance

Figure 6-10 CHEMOSYNTHESIS.

Nutritional Types ______________________ bacteria decomposers that obtain energy and materials from organic matter in their surroundings return many chemicals to the marine environment through respiration and fermentation populate the surface of organic particles suspended in the water by secreting _______________ (glue-like substance)

Nutritional Types (Heterotrophic Bacteria) association of heterotrophic bacteria with particles in the water column aids with: _______________adjacent particles adhere ______________: formation of mineral cement between particles ______________: settling of particles marine snow: large, cobweb-like drifting structures formed by mucus secreted by many kinds of plankton, where particles may accumulate