Concept Formation

•Student Generated Data

•Sorted Data- group words based on perceptions of how the terms fit

together

•Determine Concept Labels

Concept Formation

Infectious Agents

Group Formation•Separate based on the following:

▫I received some form of technology over the Holidays!

▫I received money over the Holidays!▫I didn’t get anything over the Holidays!▫I received something better over the

Holidays!

Bell Work

How does bacteria affect your everyday life? Does bacteria impact your life positively,

negatively, or both?

Objectives

•Explain how the two groups of prokaryotes differ.

•Describe how prokaryotes vary in structure and function.

•Explain the role of bacteria in the living world.

Bacteria- True or False?

1. There can be up to 25 species of bacteria living in a single mouth.

2. A milliliter of saliva can contain as many as 40 million bacterial cells.

3. 80% of pathogens (bacteria & viruses) are spread by touch.

4. 400 more germs are present on a desk than on a toilet.

5. There are an estimated 75 to 100 trillion cells in the human body.  There are more bacteria in your body than the number of cells in your body. 

Let’s Do LunchWhat are bacteria and

how are they different from other

organisms?

Let’s Do LunchWhy are most bacteria

unable to live in our bodies?

Let’s Do LunchWhere do beneficial bacteria live in our

bodies?

Let’s Do LunchWhat are some

examples of how we use bacteria for

commercial purposes?

Let’s Do LunchWhy do you think

better hygiene led to a decrease in child

mortality?

Let’s Do LunchWhat kinds of niches do you think bacteria might occupy in the

ecosystem?

Let’s Do LunchWhy do you think

bacteria are so successful at living almost anywhere on

earth?

Let’s Do LunchWhat are some ways your body prevents

against bacterial infection?

Let’s Do LunchBiologists can now manipulate

the genetic code of many bacteria, engineering them to perform tasks they might not otherwise be able to do; what are some useful purposes for theses “designer” bacteria?

Prokaryotic Characteristics•Classification & Ecology•Cell wall•Size & Shape•Structure•Reproduction & Conjugations•Mutations & Antibiotics•Metabolism•Survival

Infectious Agents•Pathogen- any substance that is able to

cause disease in an individual.▫Bacteria: prokaryote microorganism that

causes tuberculosis, pneumonia, strep throat, and staph infections

▫Viruses: non-living infectious agent that causes flu, HIV/AIDS, herpes, chicken pox, and measles

* Other infectious agents: fungus, protists and worms.

I. Prokaryote Classification

•Once classified into Kingdom Monera ▫Lack of nucleus & membrane- bound

organelles•Now divided into two domains:

a. Domain Archaeab. Domain Bacteria (most common/affect

humans)

a. Domain Archaea• Live in extreme environments (called

extremophiles)Thermoacidophiles

Halophiles Methanogens

Environment

Hot (above 80C), acidic (pH

of 1-2)

Salty Anaerobes (can’t live in presence of

oxygen)

Environment Examples

Sulfur hot springs, ocean floor thermal

vents, volcanoes

Great Salt Lake,

Dead Sea

Sewage treatment

plants, swamps,

bogs, GI tract

b. Domain Bacteria•Bacteria (Kingdom Eubacteria) •Found everywhere except in extreme

environments •Have strong cell walls w/ peptidoglycan

(sugars & amino acids)

Clostridium tetani

Corynebacterium acneClostridium

botulinum

Diplococcus pneumoniae

Bacteria & Archaea Differences

Similarities Differences• Size• Prokaryotes• Have cell walls

• Different cell wall components▫ Bacteria have

peptidoglycan▫ Archaea lack

peptidoglycan• Different lipids in cell

membrane• Different proteins &

nucleic acid

I. Ecology of Bacteria

•Nutrient Cycling▫Decomposers: return nutrients to

environment▫Nitrogen fixation

•Normal Flora▫Harmless bacteria living in & on you

•Foods & Medicine•Disease Causing Bacteria

Objectives

•Explain how the two groups of prokaryotes differ.

•Describe how prokaryotes vary in structure and function.

•Explain the role of bacteria in the living world.

II. Cell Walls (AKA Capsule)•Determines the bacteria’s shape•All bacterial cells have cell walls

▫Eubacteria- have peptidoglycan▫Archae- lack peptidoglycan; different lipids

•Dies added to bacteria to identify two types:

▫w/ outer layer of lipid▫w/o outer layer of lipid

Technique = Gram Stain

Gram Stain•Large amount of peptidoglycan= dark

purple▫Called gram positive

•W/ a lipid layer; less peptidoglycan= light pink▫Called gram negativeGram Positive Gram Negative

Why does it

matter?

Gram negative bacteria are protected against most antibiotics & chemicals by

their outer cell wall. Only certain antibiotics can work against them.

Bell WorkWhat is the difference between Gram

Positive and Gram Negative bacteria? Which one would you

rather be infected by (you can’t tell me neither)?

III. ShapeCocci

(Spherical/Round)

Bacilli (Rod-shaped)

Spirilli (Spiral-shaped)

Arrangements of Cocci

Arrangements of Bacilli

Arrangements of Spirilli

Check Your Understanding!!

Gram positiveStaphylococci

Gram negativeStaphylobacilli or diplobacilli

Gram positiveStreptobacilli

Gram positiveStaphylobacilli

Gram negative Diplococci or Coccus

Gram negativeSpirili

Gram positiveStaphlococci

IV. Size•1-10 micrometers long, .7-1.5

micrometers wide•Favorable surface area-to-volume ratio

▫Nutrients & other substances can diffuse to all parts of the cell easily

1 micrometer= 1,000,000 of a meter

3-2-1 Exit Slip

•What are 3 things you learned about bacteria classification and structure?

•What are 2 things you found interesting?

•What is 1 question you still have?

IV. Prokaryote Structure•Microscopic•Unicellular•Organelles

▫No Nucleus or nuclear membrane▫Contains circular DNA- nucleoid▫Has cytoplasm, cell membrane & cell wall▫Has ribosomes▫No mitochondria or chloroplasts

Chromosomes•Genes are found on a large, circular

chromosome in the area called the nucleoid

•Many prokaryotes also have a smaller piece of DNA called a plasmid

Capsule•Complex sugar

layer around cell wall

•Capsule Function:▫ Prevents cell from

drying out▫ Helps cell attach to

surfaces ▫ Shelters cell from

WBCs & antibiotics

CapsuleCell Wall

Cytoplasmic Membrane

Movement•Some are stationary

•Some have flagella▫Help bacteria move towards light, higher oxygen concentration, or chemicals to survive

Flagella

Pili•Hair-like structures made of protein

•Function:▫Helps cells attach to

surfaces▫Serves as a bridge

btw. cells Copies of plasmids can

be sent across this bridge giving bacteria new genetic characteristics

Pili

V. Metabolism- How they obtain energya. Heterotrophs “other feeder”- can’t

synthesize own food; take in organic nutrients from the environment or other organisms▫Called Saprotrophs or saprobes- obtain

energy by decomposing dead organisms

Metabolism- How they obtain energy

b. Photoautotroph “light self-feeder”-carry out photosynthesis ; uses inorganic molecules (CO2 and H2O) to create organic molecules for food▫Ie. Cyanobacteria

Metabolism- how they obtain energyc. Chemoautotrophs “Chemical self

feeder”- break down/release inorganic compounds containing N or S in chemosynthesis▫Ie. Nitrogen Fixing Bacteria

Bell Work

You collected bacteria on Friday, what are ideal growing

conditions for the bacteria you collected?

Outbreak, Epidemic or Pandemic?

Bacteria Collection!

1. Work in a group of 3.2. Use a wax pencil to create

3 separate sections on the bottom of your agar plate.

▫ Label the area of contamination

▫ Include your class period & initials

3. Swipe your Q-tip and smear over your agar plate.

4. Open the agar plate only when you have your sample ready.

5. Tape the top lid to the bottom.

Bell WorkWhy is it important that a bacteria has a capsule as

well as pili?

Bacteria “Wanted Poster”

•You will research one bacterial pathogen and produce a “wanted poster”

•You must follow the given parameters for the project (use your rubric).

Think Pair ShareDiscuss the following questions with your

partner:1. What do you think is more dangerous to a developed

country: A viral epidemic or a bacterial epidemic? 2. Why do viral diseases spread more quickly than

bacterial diseases? 3. If a bacteria similar to the one that caused the

Bubonic Plague was introduced in downtown Dayton next week, how serious would it be? What would be done to combat the bacteria? What strategies would we use that weren’t available in the 14th century?

VI. Reproduction•Binary Fission- asexual reproduction▫Division of cell into two genetically identical cells

(Chromosome replicates)

(Original chromosome and new copy

separate)

(New plasma membrane and cell

wall form)

(two identical

cells)

Survival of Bacteria•Endospore- dormant bacterial cell

▫Protective capsule enclosing the cell’s DNA & cytoplasm

▫Cell stays inactive when conditions don’t favor growth

▫If conditions improve, the endospore become active & normal reproduction resumes

Activity on Bacteria Growth Rate

VII. Conjugation•Two cells attach

by a pili & exchange genetic info.▫Pili: acts as a “bridge”

transferring DNA from one cell to another

▫Plasmid: extra DNA molecule separate from nucleoid (circular DNA) that is transferred

1. Donor cell produces a pilus (singlular for pili)

2. Pilus attaches to recipient cell

3. An enzyme cuts the plasmid (break in the DNA strand)

4. Single DNA strand is transferred to the recipient cell & is incorporated into the nucleiod

5. Plasmids re-circle

VIII. Mutations

•Bacteria reproduce quickly & pop. grows rapidly ▫thus mutations can help bacteria survive

changing environments New gene combinations New bacteria characteristics Genetic diversity

Objectives1. SWBAT describe the steps in prokaryote

reproduction and conjugation.2. SWBAT explain how bacterial cells can

acquire new gene combinations through conjugation or from mutations as a result of rapid reproduction.

3. SWBAT describe how a population of bacteria can evolve to become antibiotic resistant.

Q: What are Antibiotics?A: Medicine that kills bacteria w/o

killing the human host

▫Some attack the cell wall (preventing it from forming properly)

▫Some target bacterial ribosomes Does not affect eukaryotic cells b/c antibiotics

don’t disrupt protein synthesis in human cells▫Some disrupt DNA reproduction

DNA can’t be reproduced/copied for new cells

Tracking the Spread of Antibiotic Resistance

Remember: the direct transfer of plasmids between bacterial cells can sometimes

transfer genes (via conjugation) for antibiotic resistance from one bacterium to another.

Represents a bacteria cell Represent plasmids

Round 11. You will simulate bacterial conjugation▫ w/o looking exchange plasmids (5 exchanges)

2. Count your yellow plasmids▫ Record data in “After Round 1 Exchanges” ▫ How many of you have yellow bands? tally▫ How many of you still don’t have any yellow bands? tally▫ Count how many yellow bands you have in your bag &

tally

Round 21. Repeat Bacterial Conjugation

▫ w/o looking exchange plasmids (5 exchanges)

2. Count your yellow plasmids▫ Record data in “After Round 2 Exchanges” ▫ How many of you have yellow bands? tally▫ How many of you still don’t have any yellow bands? tally▫ Count the number of bands you have in your bag & tally

Round 31. You will simulate antibiotic exposure ▫ Students w/o yellow plasmids will sit out of the round▫ w/o looking exchange plasmids (5 exchanges)

2. Count your yellow plasmids▫ Record data in “After Round 3 Exchange with Antibiotic

Exposure” ▫ How many of you have yellow discs? tally▫ How many of you still don’t have any yellow discs? tally▫ Count how many yellow discs you have in your bag &

tally

Let’s Do Lunch!•Proceed to

your next lunch date

•You will be given 5-7 min. to

answer the questions on your

worksheet

My Bacteria RapMy name is bacteria and I am prokaryotic

I don’t have a nucleus; it’s so chaoticI have a cell wall and I’m oh so small

A capsule, nucleoid, plasmid and THAT is allI replicate through binary fission; I start with one and go

through divisionCreating new offspring ensures my genetic provision

I come in spherical rod shaped and spiralNO I’m not Viral!

I go through metabolism to ensure my growthEither photo, chemo, or saprotrophAntibiotics might be the death of mebut if I mutate nothing stopping me!