Compare and Contrast the Overall Cell Structure of Prokaryotes and Eukaryotes

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Facilitated diffusion: solute combines with a transporter protein in the membrane to facilitate movement

Active transport: requires a transported protein and ATP

Group translocation: requires a transporter protein and PEP; the substance being transported is chemically altered; occurs exclusively in prokaryotes

- What is the function of the nucleoid? ribosomes?

Nucleoid: contains bacterial chromosomes

Ribosomes: carry out protein synthesis

- What are inclusions (inclusion bodies)? Name four inclusions that have storage functions. Name and describe two inclusions that have functions other than storage.

Inclusions are usually used for storage.

- Metachromatic granules: phosphate reserves

- Polysaccharide granules: energy reserves

- Lipid inclusions: energy reserves

- Sulfur granules: energy reserves

Other functions include:

- Gas vacuoles: protein covered cylinders filled with gas that regulate depth in water

- Magnetosomes: iron oxide (destroys H2O2)

- What are endospores, and under what conditions do endospores form? Name two genera that are typical endospore-formers. What is sporulation? germination?

Endospores are spores formed within a bacterial cell that form under conditiond that are typically poor for growth i.e. limited nutrients.

Two genera that are typical endospore formers are bacillus and clostridium.

Sporulation is endospore formation

Germination is return to vegetative state (vegetative=growing)

- How does the structure of prokaryotic flagella differ from that of eukaryotic flagella? How do they differ in terms of their function (the way that they “work”)?

PROKARYOTIC

- Rotate like a propeller – like tiny motors

- Flagella composed of flagellin

- Attached to a protein hook, anchored to wall and membrane by basal body

EUKARYOTIC

- Whiplike motion

- 9+2 organization of microtubules

- Flagella composed of tubulin

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- What is the main component of cell walls in plants, algae, and fungi?

POLYSACCHARIDES (carbohydrates)!

Plants and algae- cellulose

Fungi- chitin

- What is the function of the eukaryotic glycocalyx?

Glue cells together and help cells recognize one another.

- How are eukaryotic plasma membranes different from bacterial plasma membranes in term of structure (what they are made of) and function (what they do)?

Both have phospholipid bilayer, peripheral proteins, integral proteins and transmembrane proteins.

Both function in transport and are selectively permeable: simple diffusion, facilitative diffusion, osmosis and active transport.

EUKARYOTIC PM

- Have sterols!

- Function in endocytosis! (phagocytosis and pinocytosis)

BACTERIAL PM

- Only some bacteria have sterols (mycoplasmas)

- Eukaryotic cells have both 70S and 80S ribosomes. Where are they located in the cell? The antibiotic erythromycin binds with the 50S portion of a ribosome. What effect does this have on a prokaryotic cell? On a eukaryotic cell?

80S ribosomes: attached to the ER or in the cytoplasm

70S ribosomes: in chloroplasts and mitochondria

The antibiotic erythromycin interferes with protein synthesis by attaching to the 50S subunit. Because of differences in prokaryotic and eukaryotic ribosomes, the microbial cell can be killed by the antibiotic while the eukaryotic host cell remains unaffected.

- Describe the functions of the nucleus, endoplasmic reticulum, Golgi complex, lysosomes, vacuoles, mitochondria, chloroplasts, peroxisomes, and centrosomes.

Nucleus: contains chromosomes; double membrane with pores for communication

Endoplasmic reticulum: transport network

Golgi complex: membrane formation and secretion; sorts proteins made in the ER

Lysosomes: digestive enzymes (hydrolytic enzymes that break things down)

Vacuoles: brings food into cells and provides support; water filled, membrane enclosed; only in animals

Mitochondria: cellular respiration; important for ATP synthesis

Chloroplasts: photosynthesis

Peroxisomes: oxidation of fatty acids; destroys H2O2

Centrosomes: consists of protein fibers and centrioles

- Compare the structure of the nucleus of a eukaryote and the nucleoid of a prokaryote.

The nucleus of a eukaryote is a double membrane with pores that allow for communication with the cytoplasm and encloses genetic material.

The nucleoid of a prokaryote contains the bacterial chromosomes, has double stranded, circular DNA. It is NOT surrounded by a membrane.

- How do rough and smooth ER compare structurally and functionally?

Rough ER has ribosomes on it where as smooth ER does not. The function of rough