Chapter 3: Intro to Prokaryotic Cells

Name two prokaryotic domains

archaea and bacteria

Do prokaryotic organisms contain membrane-bound organelles?

lack membrane bound organelles and nucleus

Are prokaryotes multicellular, unicellular, or can they be both?

unicellular

What does it mean if a bacterium is pleomorphic? What advantage does it give the microbe?

can take different forms/shapes, enhances survival and important for transmission to new human host

How do most prokaryotes obtain nutrients?

diffusion

Describe prokaryote shapes and arrangements

What reproduction process is used by most prokaryotes? Is the process sexual or asexual?

asexually through binary fission

Describe the basic structure of a cell’s plasma membrane (cytoplasmic membrane, cell membrane)? What is its main function?

outer boundary surrounding all cells, controls movements of nutrients, water, etc by being selectively permeable

Most prokaryotic cells possess a protective structure called a cell wall. In respective to prokaryote cell plasma membranes, where is the cell wall located?

lies just inside the plasma membrane

What is the core component of bacterial cell walls?

peptidoglycan(murein)

What is the core component of archaea cell walls?

one or more layers of pseudopeptidoglycan(pseudomurein)

Gram-negative bacteria have a thin layer of peptidoglycan that is surrounded by an outer membrane. What glycolipid enriches the outer membrane?

lipopolysaccharide

Which part of lipopolysaccharide is an endotoxin?

lipid portion

Where in the body would you find enteric bacteria?

intestinal tract of mammals

What is the physical reason why Gram-negative bacteria are not as susceptible to penicillin as Gram-positive organisms are?

penicillin targets peptidoglycan construction, gram-meg cells have thin later of peptidoglycan and the outer membrane adds protection they are less sensitive

Which two genera are the best-known examples of acid-fast bacteria?

Genera Nocardia and Mycobacterium

Even though the reaction is weak, are acid-fast organisms considered Gram-positive or Gram-negative?

Gram-positive

Which bacterial genus lacks cell walls?

Mycoplasma

What is the difference between L-forms and Mycoplasma?

Mycoplasma are wall-less through out their life cycle

L-forms are bacteria that had a cell wall then lost it

What is diffusion? Is it an active or passive process?

passive movement of substances from areas of high concentration to areas of low concentration

What is the difference between simple diffusion and facilitated diffusion?

simple diffusion - does not require assistance from transporters or carriers

facilitated diffusion - moves substances along their concentration gradient with the help of one more transport proteins in the plasma membrane, proteins are specific

What is osmosis? Is it an active or passive process?

water moves from area low solute concentration to an area of a higher solute concentration, passive

What is the function of flagella?

to help the bacteria move, motility

Define chemotaxis

movement of a cell in response to a chemical stimulus

Define phototaxis

movement of a cell in response to light

What is the function of fimbriae?

extrude from the cell surface to help prokaryote stuck to surfaces or each other

What is the function of pili?

used to adhere to surfaces, move, and aid in gene transfer through conjugation

What are two ways that a bacterial capsule increase pathogenicity of the bacteria?

promotes adhesion to host tissues and provides some protection against host immune cells by interfering with phagocytosis

What is the main molecule contained in the nucleoid region of a bacteria?

DNA

What is the function of ribosomes?

build proteins by linking amino acids together

How are prokaryotic ribosomes different than eukaryotic ribosomes?

prokaryotic ribosomes have lower overall mass and diameter than eukaruyotic

What is the sedimentation rate of complete prokaryotic and complete eukaryotic ribosomes?

prokaryotic - 70S

eukaryotic - 80S

With complete ribosome sedimentation in mind, what property of chloroplasts and mitochondria support the endosymbiotic theory?

the larger eukaryotic evolved from the smaller but similar prokaryote

What is the function of a prokaryotic cytoskeleton?

structure and support, organize cell division(binary fission), directs the construction of the cell wall, and provides an overall general organization for biochemical processes

What are inclusion bodies and what is their function

distinct collection of substances inside prokaryotic cells, storage reserves for nutrients, energy, or building blocks

How do endospores differ from vegetative cells?

endospores are inactive structures while vegetative cells are actively growing

Name three genera that contain the most medically relevant species that produce endospores

Bacillus, Clostridium, and Clostridioides