Cell Structure & Function Bacteria and Archaea (MICROBIO UNIT 3)

Morphology means _____

Cell shape

What are 3 major cell morphology

Coccus
Bacillus
Spirilium

What is coccus

Spherical or ovoid

What is bacillus

Rod-shaped

What is spirilium

Loose spiral shape

True or false. Smaller cells also have smaller area to volume ratio compared to bigger cells

False

Why cells desire to have a high area to volume ratio (2)

To support greater nutrient exchange per unit cell volume
To grow faster

The cytoplasmic membrane functions as a _____, _____ membrane, allowing the cell to concentrate specific metabolites internally while effectively excreting waste products.

highly selective, permeable

The general structure of the membrane is a _____ bilayer composed of both _____ and _____ components.

phospholipid, hydrophilic, hydrophobic

The _____ is a thin structure, approximately _____ nm thick, that surrounds the cell and serves as a vital barrier separating the cytoplasm from the external environment.

cytoplasmic membrane, 6-8

True or false. Membrane structure is of fluid nature

True

True or false. Membranes are very rigid and immobile

False

True or false. Archaea feature ester linkages to its phospholipids

False

Bacteria and eukarya feature _____ linkage to its phospolipids

ester

True or false. Archaea are sterol and haponoid containing organism

False

Archaeal lipids lack _____, have _____ instead

fatty acids, isoprene

True or false. Bacterial lipid will always form bilayer

True

_____ arise when cocci divide and remain together to form pairs

Diplocci

_____ are comma-shaped organism

Vibrios

_____ are rigid, spiral shaped cells

Spirilla

_____ are flexible, spiral-shaped acteria

Spirochetes

True or false. Shape affects surface to volume ratio

True

What ions help stabilize membrane by binding with nagative phospholipid

Ca2+

Mg2+

______ proteins are embedded into the membrane

Integral

______ proteins have only one portion anchored to the membrane

Peripheral

______ are similar to sterols in structure

hopanoid

True or false. Archaea utilizes ether linkages in phospholipids

True

_____ and _____ utilizes ester phospholipid linkages

Bacteria, eukarya

True or false. Archaea posseses fatty acid

False

Why did archaea opt for ether bonds rather than ester

Because it is more stabler in extreme environment

Eukarya : Ester , Archaea : _____

Ether

Eukarya : Fatty acid , Archaea : _____

Isoprene

True or false. Ester bonds are preferred by archaea because its stronger than ethers in extreme conditions

False

What are 3 functions of cell membrane

Permeability regulator
Protein anchor
Energy conservation

What are 3 major classes

Simple transport
Group translocation
ABC transport

Simple transport is driven by _____

Proton motive force

During the simple transport, the solute remains _____

unchanged

Group translocation is predominantly driven by _____

PEP

PEP stands for _____

Phospoenolpyruvate

True or false. During group translocation, the solute undergoes chemical modification effectively trapping in the cell and cannot get out

True

During _____ energy gained from PEP or _____ is used to _____ the substance effectively _____ it in the cell

group translocation, phosphoenolpyruvate, phosphorylates, trapping

the ABC in ABC transport stands for _____

ATP-Binding Cassette

ABC transporters use _____ directly as a energy source

ATP

True or false. ABC transport processes strictly in this order of steps
1) Substrate specific periplasmic binding protein captures solute
2) Binding protein brings solute to membrane-integrated transporter
3) ATP hydrolysis fuels the change in conformation required to push the solute into cytoplasm

True

What are the 3 sequence of steps used by ABC transport

1) Substrate-specific binding protein attaches to a solute
2) Binding protein brings captured solute to integrated-protein in the membrane
3) ATP hydrolysis fuels the energy required to change conformation and push solute to cytoplasm

_____ is an example of a transporter than moves a single type of molecule like K+ across a membrane in one direction

Potassium uniport

_____ is an example of a symport who imports _____ and _____

Lac permease, lactose, H+

_____ is an example of a two-way transporter who exports _____ and imports _____

Sodium-proton antiport, sodium and H+

Phosphotransferase System in _____ transports the sugars _____, _____ and _____ using _____ as energy source

e.coli, mannose, fructose, glucose, PEP

What is order of enzyme in phosphotransferase system in e.coli

PEP
Enz I
hPR
Enz II a
Enz II b
Enz II c

What is product of phosphotransferase system in e.coli

Glucose-6-phosphate

What are 3 proteins that make up ABC transport

Binding protein
Integral transport proteins
ATP-hydrolyzing protein

_____ move synthesized proteins across or into the cytoplasmic membrane

Translocases

True or false. T3SS is common in non-pathogenic bacteria

False

What does T3SS stand for

Type 3 Secretion System

T3SS is most commonly found on _____ bacteria, allowing direct transport of proteins into host cells

pathogenic

Gram-positive cell walls is composed of high _____ content making up 90% of the G+ cell wall forming a thick cable-like mesh network

peptidoglycan

Gram-positive cell walls contain _____ and _____ acid

teichoic, lipoteichoic

_____ are _____ that spans the cell wall and covalently attached to the lipid membrane serving as anchor for the peptidoglycan layer

Lipoteichoic acid, teichoic acids

Peptidoglycan is composed of…. (4)

N-acetylglucosamine
N-acetylmuramic acid
Amino acids
Diaminopimelic acid (DAP)

_____ and _____ are types of prokaryotes that lack cell wall

Mycoplasma, thermoplasma

True or false. Peptidoglycans make up 90% of a gram negative bacteria

False

In cell wall, the outer membrane is also called _____ layer

lipopolysaccharide (LPS)

_____ are a _____ protein channel that permit the passage of hydrophilic, low-molecular-weight substances across the outer membrane.

Porins, transmembrane

True or false. Structural differences in cell wall composition and thickness between Gram-positive and Gram-negative bacteria indirectly dictate their differential Gram stain behavior.

False

True or false. Archaea also possess a peptidoglycan layer

False

Archaea do not have a _____ layer and typically do not possess an _____

peptidoglycan, outer membrane

Pseudomurein is found in _____ archaea

methanogenic

Archaeal Pseudomurein is made up of _____ and _____

N-acetylglucosamine, N-acetyltalosaminuronic acid

Bacterial peptidoglycan is made up of _____ and _____

N-acetylglucosamine, N-acetyltalosaminuronic

In archaea, the pseudomurein is linked via _____ bonds, while in bacteria the peptidoglycan is linked via _____ bonds

B1-3, B1-4

True or false. Archaea are incapable of resisting lysozome and penicillin

False

In archaea only _____ amino acids are found in the pseudomurein layer

L

_____ are complex structures made of _____ and protein that function as the sites of _____.

Ribosomes, RNA, protein synthesis

In ribosome, S stands for _____ unit

Svedberg

In prokaryotes such as _____ and _____, the ribosomes have a sedimentation coefficient of _____ while in eukaryotes the sedimentation coefficient is _____

bacteria, archaea, 70S, 80S

Prokaryotic rRNA is made up of a small subunit containing _____ and a large subunit containing _____, _____

16S, 25S, 3S

_____ is an irregularly shaped region within bacteria and archaea that is typically not bound by a membrane

Nucleoid

True or false. Capsules are dense and well-organized, slime layers are loose and flexible

True

What is function of capsule and slime layer to cell

Protects from desiccation
Protects from phagocyte
Anchors cell to surfaces

_____ are short, thin protein filaments spread across the cell surface. Acting like molecular velcro, they allow cells to adhere to host tissues or cluster together to form floating biofilms

fimbriae

What is fimbriae

Are short thin protein filament spread across cell surface that functions similar to velcro

_____ is the organelle that forms a physical bridge allowing two bacteria to transfer genes

Pili

_____ are hollow, tube-like networks exclusive to extreme _____

Cannulae, thermophiles

_____ are tube-like networks that connect groups of _____ together, potentially allowing them to share _____ or _____ in _____ environments

Cannulae, daughter cells, nutrients, signals, high-temperature

_____ is a tiny, specialized archaeal filaments that terminate in a distinct three-pronged "grappling hook" structure, enabling cells to anchor securely to environmental surfaces

Hami

Gas vesicles are _____ shaped, _____ sac that allows planktonic cells to _____ in water

spindle, gas-filled, float

True or false. Gas vesicles are easily permeable to water

False

True or false. Gas vesicles can decrease cell density

True

_____ is the dormant stage of bacterial life cycle

Endospores

Endosphores are highly differentiated cell resistant to _____, _____ and _____

heat, chemical degradation, radiation

What are 5 types of microbial taxes

Chemotaxi
Phototaxi
Aerotaxi
Osmotaxi
Hydrotaxi

What is chemotaxi

Microbial response to chemicals

What is phototaxi

Microbial response to light

What is aerotaxi

Microbial response to oxygen

What is hydrotaxi

Microbial response to water

What is osmotaxi

Microbial response to ionic strength

True or false. Endospore formation is limited only to gram-negative bacteria

False

Only _____ bacteria can truly form endospores

Gram-negative

What are 3 possible endospore location

Terminal
Subterminal
Central