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This week is about .

• Review the lecture on bacteria • Watch the video about bacteria: sisters bacteria • Complete resistance reading and questions • Complete the Prokaryotic and Eukaryotic worksheet

You will be graded you based on the rubric below. If you get below a 70% I will allow you to redo the assignment.

Bacteria and

SOPHOMORE CP LAB vs. Eu = do Pro = No ◦ Eukaryotes do have a nucleus ◦ Prokaryotes have no nucleus ◦ , , , fungi ◦ Bacteria ◦ Uni or multicellular ◦ Unicellular ◦ Membrane bound (ER, ◦ No membrane bound organelles Golgi, mitochondria) Bacterial Organization

Bacteria

Eubacteria Archaebacteria

Found Found in Everywhere harsh environments

Can Live in Live in Cause of illnesses Eukaryotic cells BACTERIA Type of – ◦ A single celled that lacks a nucleus and other membrane bound organelles Bacteria Example: ◦ E.coli ◦ pneumoniae – strep throat ◦ epidermidis - staph () ◦ Methicillin-resistant - MRSA BACTERIA 1. Has wall ◦ Thick outer covering made and sometimes of (combination of & proteins) ◦ Conduct a in order to determine if peptidoglycan is present ◦ Gram + contain peptidoglycan = has ◦ Gram – no peptidoglycan = no protein BACTERIA 2. Has Cell (plasma) membrane ◦ Protects cell, regulates what enters and

3. Has ◦ Make proteins

May Have: ◦ (Flagella) – whip like tail (s)

◦ Pili – shorter thinner hair like structures

◦ Both help bacteria cells move, ◦ Not all bacteria move, some stay in place BACTERIAL DNA Two Types: 1. Chromosomal - Single circular ◦ not x shaped like eukaryotes ◦ and some proteins form a ◦ Contains all the information a bacteria needs to survive and make proteins

2. – smaller circular DNA molecules ◦ Contain just a few that help bacteria overcome stressful situations ◦ Not in all bacteria ◦ Can easily be transferred between different bacteria cells ◦ Can replicate on its own ◦ Can have hundreds of copies in a single bacteria cell Bacteria Structure

Ribosome Peptidoglycan

Flagellum Pili DNA BACTERIAL REPLICATION ◦Asexual - One parent, No sex necessary ◦Includes bacterial reproduction and in eukaryotes ◦Produces two new identical daughter cells ◦each with half new and half old DNA BACTERIAL REPLICATION Binary – bacteria cell reproduction ◦Two stages: 1. DNA Replication – DNA is copied and each new cell will have a copy of the genetic information ◦ Limited error check and regulation – frequent 2. - Cell divides pinched into two independent cells. ◦Conjugation allows bacteria to exchange genetic material with nearby bacteria

◦Direct cell to cell contact or forms a bridge using pili

◦Allows for greater genetic diversity BACTERIAL EVOLUTION ◦Bacteria can evolve rapid – we can actually witness this evolution ◦Reproduce rapidly – many generation in short period ◦Not as complex – less error check leads to frequent mutations ◦Can easily exchange genetic material through conjugation

◦This means bacteria can easily adapt in just a few generations Getting Bacteria can be: • – can preform or chemosynthesis • – engulf other and nutrients, usually use endocytosis Controlling Bacteria ◦Chemicals that inactivate the infecting organism ◦Blocks the growth and reproduction of bacteria ◦Attacks cell wall = not effective against

Antibiotics: An Overview

Antibiotics are a type of which are used to treat bacterial . Every day we encounter thousands of bacterial cells. We are colonized with lots of different types of bacteria which live on us, and inside of us; everywhere from the grooves of your fingerprint, to the nooks and crannies of your intestines. If you count all of the bacteria, they actually outnumber us (by "us" we mean our human cells) about 10 to 1. To stay healthy, we need to maintain a healthy of bacteria, called normal (not all bacteria are bad!), while selectively getting rid of the harmful, “pathogenic” bacteria which can cause an infection.

Pathogenic bacteria is a relative term. Some bacteria can cause illness in you no what. Other bacteria cause illness when they wander from their normal location (e.g. intestines) and try to live in a new location (e.g. bladder), which is what happens when you develop a (UTI). The body’s responds to an infection by trying to fight and destroy the invading bacteria!

What are antibiotics? To help the immune system, we sometimes use antibiotics, which are chemicals (specifically a swarm of small molecules) that enter and stick to important parts (think of targets) of the bacterial cell, and interfere with its ability to survive and multiply. If the bacteria are susceptible to the antibiotic, then they will stop growing or simply die.

These important parts in a bacteria include: • Proteins/sugars in the bacterial wall • Important that make new bacterial DNA or proteins

When an antibiotic molecule sticks to its target, it will disable or destroy that protein or . If enough of the antibiotic is present, the bacterial cell is crippled and either stops growing (bacterio-static effect) or simply dies (bacteri-cidal effect).

Just to be clear, antibiotics don’t affect viruses, fungi, or parasites - they only bind to bacterial cell targets so they only affect bacterial cells. In fact, they specifically target bacteria rather than human cells.

How do antibiotics work? Let's take a look at an example of one antibiotic called . Penicillin is a fabulous antibiotic because it isn't toxic to humans at concentrations that can kill bacteria and it can kill a lot of different types of bacteria. In short, penicillin causes the bacteria to weaken its own cell wall and prevents the bacteria from being able to repair itself. With a weak wall, water seeps in, and the bacteria swells up and explodes.

Antibiotic Development Over the years, several antibiotics have been discovered in or synthesized in the lab. Some antibiotics target only specific bacteria and are called “narrow spectrum” antibiotics, whereas other antibiotics target many types of bacteria and are called “broad spectrum” antibiotics. Developing completely new classes of antibiotics (as opposed to variations on existing antibiotics) is very difficult. It’s easy to find chemicals that kill bacteria, but not so easy to find substances that could be used as , even if researchers were given infinite resources! In fact, the most recent discovery of a novel antibiotic class was in 1987, more than 30 years ago (, L., 2011)! While there are a few new antibiotics currently in development, researchers don’t know if they’ll ever become usable as medicine. This void in the discovery of new antibiotics is problematic. When a bacteria becomes resistant to a specific drug within a drug class, it gains some level of resistance to drugs within the same class. For example, if a bacteria became resistant to ampicillin, it would also have some level of resistance to other penicillin-like antibiotics.

How does antibiotic resistance develop exactly? When a bacteria is exposed to antibiotics there are three possible outcomes - they will die, they will stagnate (not multiply), or they will multiply. Three main factors will predict which is more likely to happen; antibiotic concentration, bacterial , and bacterial genetic exchange.

• Antibiotic concentration Generally, the more antibiotic getting to a bacteria will cause it to stagnate/die, and less antibiotic will allow it to multiply. Some bacteria live within a “”, which is a jelly-like substance where thousands of bacterial cells are suspended inside (think raspberry in raspberry jelly). It’s sort of like a big, thick energy shield. The antibiotic has to move (diffuse) through the biofilm to reach all of the bacterial cells. Some cells that are buried deep within the biofilm are exposed to only a fraction of the antibiotic that reaches the surface. • Bacterial mutation When bacterial cells replicate, there is a small chance the new bacterial cell will not be exactly the same as the original bacterial cell. We call these errors in the copied cell a mutation. In one bacterial cell, the cell wall could be slightly different, in another an enzyme works poorly, and so on. Mutations are key to the idea of evolution, and all of the diversity you can see in nature came from a series of many mutations over hundreds of thousands of years. In , it can take centuries or millennia for a to adopt a mutation which helps it survive and reproduce. Bacteria on the other hand can multiply within hours, allowing for more mutations to occur over a shorter period of time. These mutations can make it difficult for the antibiotics to enter the bacteria or stick to it, making the antibiotic less effective at hurting or killing the bacteria. • Bacterial genetic exchange A curious of bacteria is that they love to share information when they meet. This happens even between two different bacterial species. As a result, once a single bacterial species has managed to resist antibiotics with a (s), that gene(s) can get copied and passed around to other bacteria. It’s like passing around a juicy bit of gossip - as more meetings occur, more and more bacteria learn how to resist an antibiotic! How do you prevent bacteria from developing antibiotic resistance? To limit antibiotic resistance, it’s important to limit the exposure that bacteria all over the planet (inside of us, within animals, and living in the environment) have to antibiotics. two ways you can help make sure bacteria are not getting overexposure to antibiotics are:

• Taking antibiotics responsibly: Take antibiotics only if you have a bacterial infection (not a ), and pick one that is narrow spectrum so that it doesn’t kill off your healthy bacterial ecosystem. • Trash antibiotics responsibly: Disposal of antibiotics should be done in a way that minimizes the exposure of bacteria living in the environment to the antibiotic. For example, you shouldn’t crush antibiotics or flush them down the toilet. That gives the antibiotics direct access to bacteria living in the soil and water. Instead, two options are to either give them back to a pharmacist for disposal or to put them into a sealed plastic bag and toss it into the trash.

Multiple Choice Questions:

1. Antibiotics are a type of medicine used to treat what? a. Viruses b. Fungi c. Bacteria d. Parasites

2. All bacteria is bad. a. True b. False

3. All of these are important parts of bacteria except which of the following? a. Proteins/sugars in the bacterial wall b. Cell membranes c. Important enzymes d. None of the above

4. When an antibiotic molecule sticks to its target, it will disable or destroy that protein or enzyme. If enough of the antibiotic is present, what will happen to the bacterial cell? a. The bacteria is crippled b. The bacteria will stop growing c. The bacteria will simply die d. All of the above can happen

5. Antibiotics specifically target bacteria cells, so they don’t destroy human cells. a. True b. False

6. What does Penicillin do to the bacteria? a. Makes the bacteria stronger so that it becomes resistant to the antibiotics b. Weaken the bacteria’s cell wall and prevents it from being able to repair itself c. Creates a protective barrier around the bacteria so it cannot move d. Forces the bacteria to communicate with other cells 7. What type of antibiotics target only specific bacteria? a. Broad spectrum antibiotics b. Wide spectrum antibiotics c. Narrow spectrum antibiotics d. Simple spectrum antibiotics 8. What type of antibiotics target many types of bacteria? a. Broad spectrum antibiotics b. Wide spectrum antibiotics c. Narrow spectrum antibiotics d. Simple spectrum antibiotics

9. When was the most recent discovery of a novel antibiotic class? a. 2020 b. 1993 c. 1987 d. 1965

10. What does it mean for bacteria to become antibiotic resistant? a. Bacteria will take less time to die after exposure to the antibiotic b. Bacteria develops a level of resistance to the antibiotic so that it will not die c. Bacteria will react to the antibiotic faster making them less resilient d. Bacteria will join forces with the rebellion to defeat the Sith’s army

11. Which of the following is not a possible outcome when bacteria is exposed to antibiotics? a. they will die b. they will stagnate (not multiply) c. they will multiply d. the empire strikes back

12. What is antibiotic concentration? a. There is a chance the new bacterial cell will not be exactly the same as the original b. The bacteria will remain hidden from the antibiotic within a human cell c. Bacteria will share information with each other on how to resist an antibiotic d. Only some of the bacteria that is in the biofilm is exposed to the antibiotic

13. What is bacterial mutation? a. There is a chance the new bacterial cell will not be exactly the same as the original b. The bacteria will remain hidden from the antibiotic within a human cell c. Bacteria will share information with each other on how to resist an antibiotic d. Only some of the bacteria that is in the biofilm is exposed to the antibiotic

14. What is bacterial genetic exchange? a. There is a chance the new bacterial cell will not be exactly the same as the original b. The bacteria will remain hidden from the antibiotic within a human cell c. Bacteria will share information with each other on how to resist an antibiotic d. Only some of the bacteria that is in the biofilm is exposed to the antibiotic

15. What are the two ways you can help make sure bacteria are not getting overexposure to antibiotics are: a. Taking antibiotics responsibly b. Trash antibiotics responsibly c. Trading antibiotics responsibly d. Both A and B e. Both A and C Name______Date______Comparing Prokaryotic and Eukaryotic Cells Directions: Read through each statement below. Determine if the statement is true or false. If the statement is true, write the letter “T” in the provided. If the statement is false, write the letter “F” in the space provided.

_____1. Prokaryotic cells are the more complex of the two types of cells.

_____2. Bacteria are an example of prokaryotic cells.

_____3. You are made up of eukaryotic cells.

_____4. Prokaryotic cells do not have a nucleus.

_____5. Eukaryotic cells do not have a nucleus.

_____6. Eukaryotic cells are typically smaller than prokaryotic cells.

_____7. Both prokaryotic and eukaryotic cells have a cell membrane.

_____8. Only prokaryotic cells contain a .

_____9. Both prokaryotic and eukaryotic cells contain membrane bound organelles.

_____10. Organisms made up of eukaryotic cells may be unicellular or multicellular.

Directions: Identify the prokaryotic cell below. Write a P in the corresponding box. Identify the eukaryotic cell below. Write an E in the corresponding box.

Directions: Complete the paragraph below. All living things are made up of cells that can be classified as prokaryotic or eukaryotic. ______cells are simple cells while ______cells are more complex. Prokaryotic cells are like a small house while eukaryotic cells are like a mansion because ______.

© Science from the South 2018