MBIO 101 WSU- EXAM 1

Cell membranes are made up of what?

Phospholipid bilayer (hydrophillic heads, hydrophobic tails)

What is the function of the cell membrane?

To be a selective barrier between the intracellular fluid & extracellular fluid

List 3 types of movement through a cell membrane

-Simple diffusion
-Facilitated diffusion
-Active transport

Describe a gram (+) bacterial cell wall

-Stains purple
-Thick peptidoglycan layer
-Sensitive to heating, acids, & penicillin

Describe a gram (-) bacterial cell wall

-Stains pink
-Thin peptidoglycan layer
-Lipopolysaccharide layer

Which bacterial cell wall would an antibiotic NOT be used on & why?

Gram (-) cell wall because when bacteria w/ these cell walls die, they release an endotoxin, Lipid A, that causes full-body shutdown.

Which bacterial cell wall would an antibiotic be used on & why?

Gram (+) cell wall because the antibiotic can kill the bacteria w/out harming the host.

List a bacteria w/ an Atypical cell wall. What animal is a carrier of an atypical cell wall microbe?

Mycobacterium (leprosy, TB); armadillos

What is a biofilm? List 2 places a biofilm can be found

A group of microorganisms that stick together & adhere to surfaces; teeth & rocks in a river

List 3 unique anatomical structures that allow bacteria to produce biofilms

capsule, slime layer, & fimbriae

Give an example of a bacteria that could produce endocarditis

Streptococcus mutans

Why are endospores formed?

To protect the bacteria from environmental stress, allowing them to survive

List 3 unique structural features of an endospore

-double cell membrane
-thick, waxy overcoat
-thicker peptidoglycan layer

List 2 unique structures or characteristics of a bacterial flagella

-Rotates 360 degrees 100,000 times/minute
-If it breaks it grows back

List 2 functions of bacterial flagella

-Motility through tissue
-Anchors to tissue

Explain 2 control mechanisms that can stop bacterial flagella. What antibiotic can stop bacterial flagella?

-Heat & chemicals
-tetracycline

What microbe uses its flagella to travel through tissue? Why are we concerned w/this microbe?

Listeria sp; can travel from the intestine to uterus, cross placenta, and kill the fetus in the 1st trimester in pregnant women

What is the name of bacterial replication?

Binary fission

Explain 3 methods by which genetic variation occurs in a prokaryotic cell

-Transduction: a bacteriophage injects its DNA into a host bacteria
-Transformation: a capsule of a bacteria is destroyed and the DNA from this cell moves into a capsule-free cell; causing it to grow a capsule
-Sex pili: hollow tube grown from one bacterial cell to another in order to share genetic information

What is the structural shape of human DNA? What is it called?

Double helix w/ a phosphate backbone; Deoxyribonucleic acid

What is the structural shape of bacterial DNA? What is it called?

Circular; nucleoid

What is the name of the extra piece of DNA in bacterial cells? What is its function?

Plasmid; can carry info for antibiotic resistance and adaptations to environment

Where do transcription and translation occur in a bacteria?

Cytoplasm

Where does transcription and translation occur in a human/animal cell?

Ribosome & cytoplasm

Why is the ribosome size difference important in human vs. bacterial cells?

Because antibiotics can only treat bacterial-sized ribosomes so they do not shut down the protein synthesis of necessary cells in humans.

What is the function of an inclusion granule in a bacteria? What can be found in genetically altered bacteria?

Storage of material/nutrients/metals (Iron, lead, zinc, sulfur); can have numerous inclusion granules

List 3 minerals and their functions in a prokaryotic and eukaryotic cell.

-O2: ATP production
-H: Basis for water
-C: Base for everything!

List 3 vitamins and their functions in prokaryotic and eukaryotic cells

-Vitamin C: antioxidant
-All B vitamins (thiamin, riboflavin, niacin): ATP production

List 5 structures the are unique to prokaryotes, 5 that are unique to eukaryotes, and 5 that both cell types have

-Prokaryotes: unicellular, nucleoid, cell wall, plasmid, capsule -Eukaryotes: Multicellular, nucleus, mitochondria, double helix DNA, endoplasmic reticulum -Both: DNA, cell membrane, cytoplasm, ribosomes, flagella

2 benefits/applications of bacteria

-Making products such as yogurt
-Can protect from infection

2 bacteria that can cause disease

-Streptococcus mutans
-E. coli

List 2 non-bacterial microorganisms

-Fungi
-Protozoa

List 3 protein structures found in bacterial cells & 3 protein structures found in human cells

-Bacterial cells: slime layer, capsule, pillus
-Human cells: Hair, nails, sperm

How many ATPs are produced from a carbohydrate in prokaryotes? Eukaryotes? What is the function of a carbohydrate in these cells?

-Prokaryotes: 38 ATPs
-Eukaryotes: 36 ATPs
-Function: mechanical, transport, and chemical work (requires energy; ATP)

How many ATPs are produced from a triglyceride in prokaryotes? Eukaryotes? What is a function of a triglyceride in these cells?

-Prokaryotes: 129 ATPs
-Eukaryotes: 129 ATPs
-Function: ATP/energy

What is the function of phospholipids in prokaryotes & eukaryotes?

-Prokaryotes: cell membrane
-Eukaryotes: cell membrane

What are two functions of cholesterol in prokaryotes & eukaryotes?

-Prokaryotes: some of the cell wall, prevents melting/freezing of the cell
-Eukaryotes: Hormones, cell membrane

What structure protects a microbe from phagocytosis?

Capsule

Give 2 examples of bacteria that produce endospores

clostridium botulinum, clostridium tetani

What is "normal flora"?

Microorganisms that commonly live in/on you, protect you most times

What is the infection that occurs when the normal microbia of the intestinal tract is disturbed? How is it treated?

Clostridium difficle infection; treated by taking capsules full of fecal matter in order to replace crucial microbes

Penicillin originally came from what?

A fungus

Coccus is what shape?

Round

Bacillus is what shape?

Rod-shape

Vibrio is what shape?

Boomerang

Spirillum is what shape?

Wavy

Spirochete is what shape?

Corkscrew (found in water)

What is the microbe that causes pneumonia?

Streptococcus pneumoniae

What is the microbe that is commonly known as anthrax?

Bacillus anthracis

Difference between cytotoxins & endotoxins?

-Cytotoxins: attach to cells & destroy them
-Endotoxins: travel in blood & can shut down all organs

What microbe causes stomach ulcers?

Heliobacteria pylori (H. pylori)

What is Koch's postulate?

Culturing a microbe to find out what it is, infecting an organism with it again, isolating and culturing the microbe again to find out if it is the same microbe found in the beginning

What is an example of a Gram (+) cell wall bacteria?

Staphylococcus aureus

In prokaryotes, the flagella and the electron transport chain are embedded where?

Cell membrane

What are gas vesicles?

Small, rigid structures that allow buoyancy of the cell (floating up or down)