Bacteria and Protists

1
Bacteria and Protists

• Chapters 3 and 4
• Red Book

2
Characteristics of Bacteria

• Bacteria are living cells that carry on all the
  processes of life.
• Bacteria live everywhere
• On food and in drinks
• In the air
• On the surfaces of everything you touch
• 1000s of meters underground
• On your skin
• In your body

3
Structure of Bacteria

• 3 basic shapes
• Cocci round spheres
• Bacilli rod shaped
• Spirilla spiral shaped
• Contains cytoplasm surrounded by a cell membrane
  and a cell wall
• Genetic material in the cytoplasm
• Circular piece of DNA called Plasmid
• Ribosomes in the cytoplasm

4
Obtaining Food and Energy

• Producers - Some bacteria with chlorophyll make
  their own food. Other bacteria use energy from
  chemical reactions to make food.
• Consumers Do not make their own food. Can
  break down dead organisms to obtain energy or
  live as parasites and get energy from their hosts.

5
Classification of Bacteria

• Two kingdoms
• Eubacteria the larger of the 2 kingdoms,
  diverse organisms. Grouped according to cell
  shape and structure, the way they obtain food,
  type of food they eat and the wastes they
  produce.
• Archaebacteria contains bacteria that often is
  found in extreme conditions.

6
Beneficial Bacteria

• Most bacteria is helpful, only a few cause
  illness
• Bacteria in your intestines produce Vit. K, some
  produce antibiotics
• Some bacteria decompose dead material and help
  recycle nutrients
• Some change nitrogen in the air into nitrogen
  that plants can use.
• Some help clean up the environment
• Some are in food cheese, yogurt, vinegar,
  pickles

7
Harmful Bacteria

• Some bacteria are known as pathogens
• A pathogen is any organism that causes disease
• Enter body through cut in skin, inhaled, or
  various other ways
• Once inside the body, they multiply, damage
  normal cells, and cause illness and disease
• They may produce toxins as well

8
Pasteurization

• The process of heating food to a temperature that
  kills most harmful bacteria but causes little
  change to the taste of the food.

9
Treating Bacterial Diseases

• Antibiotics destroy bacteria in various ways
• Vaccines prevent bacterial diseases

10
Protists

• What exactly is a protist?
• Its a one- or many-celled organism that lives in
  moist or wet surroundings. They are all made of
  eukaryotic cells.
• They are divided into 3 groups plant-like,
  animal-like, and fungus-like.

11
Plant-Like Protists

• These protists contain chlorophyll in
  chloroplasts and can make their own food.
• Many have cell walls like plants.
• Some have structures that hold them in place.
• Also known as Algae. Maybe one or many celled.
• Not all are green!

12
Types of Plant-Like Protists

• Diatoms found in water, look yellow-brown,
  their cell walls contain silica. They are used
  in road paint.
• Dinoflagellates have 2 flagella which cause the
  cell to spin. Almost all live in salt water.
  Most have chlorophyll and make their own food,
  however some dont and must feed on other
  organisms.

13
More Types of Plant-Like Protists

• Euglenoids Have characteristics of both plants
  and animals. Many have chloroplasts, many move by
  whipping their flagella.
• Green algae about 7,000 species. The most
  plant-like of all the algae. Most live in water
  although others can survive in moist environments.

14
And Even More Types of Plant-Like Protists

• Brown Algae usually found in cool, salt-water
  environments. Many-celled and vary in size.
  Giant kelp is the largest organism in the protist
  kingdom and can grow to be 100m in length.
• Red algae sometimes called seaweed, it contains
  both chlorophyll and lots of red pigment. It
  lives up to 200 m deep in the ocean.

15
Importance of Algae

• Most animals that live in the ocean either eat
  algae themselves, or they eat an animal that eats
  algae. Algae is an important source of food.
• They produce oxygen
• Used in foods and products cosmetics,
  toothpastes, puddings, salad dressings, ice cream
  and marshmallows, rubber tires and hand lotion.

16
Animal-Like Protists

• Also known as protozoans
• Different types ciliates, flagellates,
  pseudopods, and non-movers
• They are classified by how they move

17
Ciliates

• Protists with cilia, or short threadlike
  structures that extend from the cell membrane
• These cilia beat in a coordinated way, causing
  the organism to swiftly move.
• They usually eat bacteria thats swept into the
  oral groove wastes are removed through the anal
  pore

18
Flagellates

• Move through their environment by whipping their
  long flagella (tail).
• Many live in fresh water, some are parasites that
  harm their hosts.

19
Pseudopods

• Pseudopod false foot
• Move through their environment by extending their
  cytoplasm in temporary extensions called
  pseudopods
• They also use their pseudopods to capture their
  prey.

20
Importance of Protozoans

• Important source of food for larger organisms
• Some cause diseases in humans

21
Fungus-like Protists

• Slime molds help dead things decay
• Water molds, downy mildews live in water or
  moist environments. Most are parasites that feed
  on plants and animals and kill them, some feed on
  dead organisms

22
Importance of Fungus-like Protists

• Help break down dead organisms
• Cause diseases in plants and animals
• Downy mildews can have huge effect on economics
  cause the Irish potato famine, still affects
  crops today