Title: Chapter 10 Overview
1Chapter 10 Overview
- Section 1
- Bacteria
- Kingdom reference Archaebacteria and Eubacteria
- Section 2
- Bacterias role in the world
- Bacteria and plants
- Bacteria role in medicine
- Bacteria as poison producers
2Chapter 10 Overview
- Section 3
- Viruses
- The discovery of Viruses
- Vaccines
3Vocabulary for Section 1
4Section 1 Bacteria
- They are the smallest and simplest organisms on
earth. - They are also the must abundant.
- A gram of earth, which is about the size of your
pencil eraser, can contain as many as 2.5 million
bacteria. - All organisms fit into one of the six Kingdoms we
discussed last chapter.
5Section 1 continued
- The two Kingdoms that bacteria fall under are
Archaebacteria and Eubacteria. - These two Kingdoms contain the oldest forms of
life on earth, in fact for 2 billion years they
were the only life forms on earth. - Bacteria are single cell organisms and their
cells contain no nucleus. They are prokaryotic
cells which you should already know. - Prokaryotes are able to perform cellular
respiration, move around, and reproduce. Because
of these abilities they can function as
independent organisms.
6Section 1 continued
- Prokaryotes reproduce by a simple cell division
called - Binary Fission The process is the DNA
replicates before cell division. The DNA and its
copy attach to the inside of the cell membrane.
As the cell grows and the membrane grows longer,
the loops of DNA become separated. When the cell
is about double in size, the membrane pinches
inward. A new cell wall forms, separating the
two new cells and their DNA.
7Section 1 continued
- Endospores
- Bacteria that grow a thick protective membrane to
protect them from an unfavorable environment.
Once they are released from the harsh environment
the endospores will break open and become active
once again.
8Section 1 continued
- The most common shapes of Bacteria
- Bacilla
- Rod shaped bacteria. Have a large surface area,
which helps them absorb nutrients, but they can
also dry out easily - Cocci
- Spherical bacteria. They are more resistant to
drying out than rod shaped bacteria. - Spirilla
- Long spiral shaped bacteria. This is the least
common shape for bacterium. Spirilla move easily
in a corkscrew motion, using flagella at both
ends.
9This is a picture of the worlds larges bacteria
from the intestines of a surgeonfish. About the
size of a pin head.Its name is Epulopiscium.
10CocciSpherical bacteria. They are more
resistant to drying out than rod shaped bacteria.
11SpirillaLong spiral shaped bacteria. This is
the least common shape for bacterium. Spirilla
move easily in a corkscrew motion, using flagella
at both ends.
12Lactobacillus acidophilus (lack-toe-bah-sill-us
acid-off-ill-us) one of the bacteria gang wanted
for turning milk into yogurt.
13Saccharomyces cerevisiae (sack-arrow-my-seas
sair-uh-vis-ee-ay) a.k.a. baker's yeast. Wanted
for making bread rise.
14Streptomyces (strep-toe-my-seas) soil bacteria
wanted for making streptomycin, an antibiotic
used to treat infections.
15Pseudomonas putida (sue-doe-moan-us poo-tea-dah)
one of many microbes wanted for cleaning wastes
from sewage water at water treatment plants.
16Escherichia coli (Esh-er-ish-e-ah coal-eye) one
of many kinds of microbes that live in your gut.
Wanted for helping you digest your food every day.
17Section 1 continued
- Kingdom Eubacteria
- This Kingdom is the largest and contains more
different types of organisms than any of the
other five Kingdoms. - Eubacteria are classified by the way they obtain
food. - Consumers obtain nutrients from other organisms
- Parasites obtain food by invading other organisms
to obtain food. - Producers make their own food and some use the
process of photosynthesis. They contain
chlorophyll.
18Section 1 continued
- Kingdom Archaebacteria
- They thrive in places where no other living
things are found. - 3 types of Archaebacteria
- Methane Makers, excrete methane gas. Found in
swamps and landfills. - Heat lovers live in places like ocean rift vents
where the temperatures reach 360 degrees Celsius.
- Salt lovers live in places where the salt
concentration is very high like the Dead Sea.
19Section 1 Review
- Draw and label the three main shapes of bacteria.
- Describe the four steps of binary fission.
- How do eubacteria and archaebacteria differ?
- Many bacteria cannot reproduce in cooler
temperatures and are destroyed at high
temperatures. How do humans take advantage of
this when preparing and storing food?
20Section 1 Review Answers
- 1. The drawings should resemble the pictures on
page 226. - 2. The cell grows, the DNA replicates, the DNA
molecules separate as the cell grows, and the
cell splits in two. - 3. Eubacteria and archaebacteria are genetically
different. Their cell walls are also chemically
different. - 4. Humans store food in refrigerators and
freezers to slow bacterial growth. Humans also
cook food at high temperatures, which helps kill
many bacteria.
21Section 2Bacterias Role In the World
- Vocabulary for Section 2
- Bioremediation
- Antibiotic
- Pathogenic Bacteria
22Section 2 Continued
- Some bacteria cause disease and because of this
they got a bad reputation. - Bacteria do many things that are important to us
humans. - Life as we know it could not exist without
bacteria. They are vital to our environment and
we benefit from them in several ways.
23Section 2 Continued
- Nitrogen-fixing(1st helpful use)
- Nitrogen is an essential element for all
organisms because it is a component of proteins
and DNA. - Plants must have nitrogen in order to grow
properly. - You would think this to be easy as 75 of our air
is made of nitrogen. - Plants, however, cannot take in nitrogen from the
air and must get it in a different form.
24Section 2 Continued
- Nitrogen-fixing bacteria consume nitrogen in the
air and change it into a form that plants can
use. - Recycling(2nd helpful use)
- Breaking down dead organic matter, decomposing
bacteria make nutrients available again to living
things. - Cleaning up(3rd helpful use)
- Bacteria are being used to combat pollution.
- Bioremediation is the use of bacteria and other
microorganisms to change pollution into harmless
chemicals. - It is used to clean industrial wastes, as well as
spills.
25Section 2 Continued
- Bacteria is good for people
- Genetically engineered bacteria is used for many
things such as medicines, insecticides,
cleansers, adhesives, foods. - Fighting bacteria with bacteria
- Although some bacteria cause disease, other
bacteria make chemicals that treat diseases. - Antibiotics are medicines used to kill bacteria
and other microoganisms. Many bacteria have been
genetically engineered to make antibiotics in
large quantities.
26Section 2 Continued
- Insulin
- Again, genetic engineering to the rescue in
making human insulin. Scientist put genes
carrying the genetic code for human insulin into
E. coli bacteria. The bacteria produce human
insulin, which can be separated from the bacteria
and given to diabetics.
27Section 2 Continued
- Feeding Time
- People breed bacteria for food!
- Every time you eat cheese, yogurt, buttermilk or
sour cream, you also eat a lot of lactic acid
bacteria. Lactic acid bacteria digest the milk
sugar lactose and convert it into lactic acid.
The lactic acid acts as a preservative and adds
flavor to the food.
28Section 2 Continued
- Harmful Bacteria
- Pathogenic Bacteria
- These bacteria invade the host and obtain
nutrients from the hosts cells. - Some diseases caused by bacteria are
- Dental cavities, ulcers, strep throat, food
poisoning, TB, etc. - Pathogenic Bacteria also attack plants, protists,
fungi, and even other bacteria.
29Section 3 Viruses
- Vocabulary for Section 3
- Virus
- Host
30Section 3
- Its a small world
- About 5 billion of them could fit into a drop of
blood - Because of size and ever changing nature,
scientist dont know how many types of viruses
exist. - There could be billions
31Section 3, Continued
- Alive or Not ?
- They dont eat, breath, grow, move, or perform
any biologic functions. - A virus cannot live on its own.
- It can however reproduce (in the host) and
control its host. - A host is an organism that supports a parasite.
- Using the hosts cell as a miniature factory,
viruses instruct the cell to produce viruses
rather than healthy new cells.
32Some of the more common Viruses-The flu virus
33Some of the more common Viruses-Ebola
34Some of the more common Viruses-Rota virus
35So Exactly what is a Virus
- Plain and simple
- It is some form of genetic material enclosed in a
protein coat.
36How Destructive
- HIV is a virus that causes AIDS.
- The one thing they share with living things is
that they reproduce. - Their reproductive cycle is called the lytic
cycle. - In this cycle stage 1 is to find a host cell.
- Stage 2, the virus enters the cell or injects
genes into the cell. - Stage 3, once the genes are injected into the
cell, the cell becomes a virus factory. - Stage 4, The new viruses break out of the host
cell ready to find a new host and repeat the
cycle.
37Is that all there is?
- No
- Some viruses dont go straight into the lytic
cycle. These viruses inject their genes into the
host cell, but no new viruses are made right
away. - So What?
- When the host cell divides, each new cell has a
copy of the viruss genes. - This is called the lysogenic cycle.
- The viral genes can remain inactive for a long
time until a change in the environment, or stress
to the organism causes the genes to launch into
the lytic cycle. - Just when you thought you were safe!!
38Section 3 Review
- What would happen if one generation of measles
viruses never found a host? - Describe the four stages of the lytic cycle.
- Do you think modern transportation has had an
effect on the way viruses are spread? Explain.
39Review Answers
- Measles would die out. Viruses cannot reproduce
themselves without a host. - See page 235 for 2
- People and livestock are much more mobile now,
and thus, able to bring viruses to new places.