1. Chapter 5 Bacteria: Diatoms / Dinoflagellates

2. Bacteria
unicellular
small size (about 250,000 average-sized bacteria could fit on one period.)
simplest organisms
have a cell wall and cell membrane
no nucleus nor membrane bound organelles

3. Two Domains
Bacteria are found in most places (soil, water, internally, any surface)
Archaea often found in extreme conditions (high temperatures, high salinity, extreme cold, no oxygen)

4. Bacteria Identification by shape
bacillus (rod)

5. Bacteria Identification by shape
coccus (sphere)

6. Bacteria Identification by shape
spirilla (spiral)

7. Bacteria Identification by shape
Ring
amorphic (shapeless)

8. Bacteria Identification
can be identified using Gram stain
stain interacts with cell walls to color purple (positive) or pink (negative)

9. Bacteria Features
flagella – Latin for “whip”; whip-like appendage that protrudes from the cell body and used for the propulsion or movement of the cell

10. Bacteria Features
pilli – Latin for “hair”; hair-like appendage found on the surface of many bacteria used for the transfer of DNA between bacteria

11. Bacteria Features
capsule –covering around cell wall; function is for protection or means of attachment
DRAW BACTERIA CELL AND LABEL 3 MAIN PARTS

12. Bacteria Importance
Beneficial (decomposition/recycling of nutrients; food chains; bioluminescence for animals)
Harmful (food poisoning; disease)

13. Heterotrophic Bacteria
get energy by consuming others
consume organic matter, make up part of a food chain
some are decomposers that break down dead matter which is important for recycling nutrients

14. Autotrophic Bacteria
bacteria that make their own energy (2 types: photosynthetic and chemosynthetic)
photosynthetic – uses sunlight
chemosynthetic – uses chemical compounds like hydrogen, ammonia, hydrogen sulfide

15. Photosynthetic Bacteria (cyanobacteria)
“blue-green algae”
have chlorophyll like plants as well as phycocyanin (blue pigment)
among the oldest living things
thought to have added oxygen to the atmosphere

16. Chemosynthetic Bacteria
were called “extremophiles” – lovers of the extreme
found along hydrothermal vents and can survive EXTREME temperatures
form part of the food chain and live inside animals like tube worms

17. Diatoms Eukaryotic single-celled photosynthetic algae
Divided into two major groups based on the structure and shape of the valves. (Centrics and Pennates)
do not propel themselves up and down in the water column, but are dependent on oceanic currents for transport

18. Diatoms
The presence of chlorophyll and accessory pigments give them a golden color and serves to harvest light energy from the sun

19. Diatoms
Cells are encased in transparent glass-like (silica) “container” called a frustule that resembles a petri-dish.
The frustules can be ornate and very beautiful, and due to the resistance of silica, they form an important part of the fossil record

20. Diatoms
Cells may form chains or colonies and may have distinctive shapes or structures which help them stay afloat.
Up to 100,000 species of diatoms have been recorded world-wide.

21. Dinoflagellates Eukaryotic single-celled algae
Many have two flagella, which allow the cells to have limited mobility
Cells are covered by a theca (sheath) that can be smooth or ornamented

22. Dinoflagellates
Some species are able to migrate vertically through the water column (vertical migration), seeking nutrients, prey, or protection from harmful UV rays.

23. Dinoflagellates
Nearly half of known species are capable of photosynthesis and contain light-harvesting pigments (autotrophs)
Some species survive by other nutritional modes, and may absorb organic matter or engulf prey (heterotrophs)

24. Dinoflagellates
Of the 2000 known species, about 60 are able to produce complex toxins