BIO124 Unit 5 Exam

Contrast eukaryotic vs. prokaryotic cells based on DNA location and size

- Eukaryotic: inside membrane-bound nucleus; larger in size - Prokaryotic: no membrane-bond nucleus...in toughly bound nucleoid ring, smaller in size

How does the host cell respond to infection?

- Harmful things enters the body - Antibodies "mark" harmful thing as bad - Immune cells attack harmful things

Describe an antibody's location, occurrence, shape, and producer

- In blood stream - Highly abundant - Y-shaped with variable and constant regions - Secreted by B cells

Explain the anatomy of a flu virus

- Nucleoprotein middle (RNA) - Capsid layer - Lipid bilayer envelope - Capsid proteins: hemagglutinin (Hx), neuraminidase (Nx)

Smooth ER

- Structure: attached to rough ER, vesicles budding, membranes - Function: protein sorting and production of lipids (including phospholipids for vesicles), steroids, and oils; creates phospholipids for membranes and vesicles

Peroxisome

- Structure: compartment with crystalline core, single membrane, sphere - Function: Break down harmful substances via oxidation, detoxifies the cell, break down fatty acids

Nuclear pore

- Structure: complex, multiple proteins, goes through nuclear envelope - Function: specific selective transport

Lysosome

- Structure: contains hydrolytic/digestive enzymes, lipid bilayer - Function: break down unwanted enzymes, glycolipids - If not there, cell would starve

Flagella

- Structure: contains pairs of microtubules arranged in a circle, long, tail-like projection - Function: cell motility, propel the cell through a substance

Chloroplast

- Structure: double layer membrane, stacks of thylakoids and stroma - Function: photosynthesis (CO2 and H2O to O2 and C6H12O6...glucose), makes plants green

Nucleus

- Structure: double lipid bilayer envelope with nucleolus and genetic material - Function: houses genetic material and site of DNA replication and RNA transcription

Cilia

- Structure: fingerlike projections from a cell - Function: beat rhythmically to transport something across a membrane (ex. oocyte across fallopian tube)

Golgi apparatus

- Structure: folded membraneous sacs that bud into vesicles - Function: sorts, modifies (finish folding, carbohydrate attachment), and packages proteins as they move from the cis face to the trans Golgi to be packed into vesicles

Rough ER

- Structure: folded membranes studded with ribosomes - Function: protein synthesis and folding of tertiary structure

Vacuole

- Structure: large, membrane-bound sac in cytoplasm of plant cell (takes up much volume) - Function: water storage, waste disposal, macromolecule storage, pigments nutrients stored, help in growth

Centrosome (cell division)

- Structure: nine bundles of microtubule triplets - Function: form the mitotic spindle and facilitate cell division

Mitochondria

- Structure: outer membrane and inner membrane with many folds (cristae) and matrix inside - Function: cellular respiration to produce ATP

Plasma membrane (PM)

- Structure: phospholipid bilayer studded with protein channels, carbohydrates, cholesterol - Function: forms a semi permeable barrier between the cell and outside environment; regulates the diffusion of substances in and out of cell

Vesicles

- Structure: round phospholipid bilayer - Function: creates a transportation vehicle to protect things from the aqueous solution of the cell environment; transported along microtubule tracks via kinesin

Ribosome

- Structure: two subunits with three holding sites - Function: where mRNA is translated into a polypeptide

Articulate the risk factors for pandemics

- Virus virulence - Population's overall health (i.e. when it was depleted post WWII) - Proximity

Prokaryotic, eukaryotic, or both: genetic information is DNA

Both

Prokaryotic, eukaryotic, or both: presence of an outer cell wall

Both

Prokaryotic, eukaryotic, or both: presence of cytoplasm

Both

Prokaryotic, eukaryotic, or both: presence of phospholipid plasma membrane

Both?

Grana, thykaloids, and stroma are components found in

Chloroplasts

Explain the subtypes of influenza virus and their origins

Different viruses evolve in the wild through reassortment of the capsid proteins; these form new symptoms and a new virus so the treatment will look different. To combat viral evolution, a new quadrivalent vaccine is made each year to hopefully target the predicted assortment of virus proteins in the next flu season

Cells of the pancreases will incorporate radioactively labeled amino acids into proteins. This "tagging" of newly synthesized proteins enables a researcher to track their location. In this case, we are tracking an enzyme secreted by pancreatic cells. What is the most likely pathway?

ER --> Golgi --> Vesicles that fuse with the PM

Prokaryotic, eukaryotic, or both: presence of a nucleus

Euk

Which organelle produces and modifies polysaccharides and proteins that will be secreted?

Golgi apparatus

Distinguish between the two types of influenza projected for 2019-2020.

H1N1: easily spread, rarely fatal, upper respiratory (nasopharynx) H3N2: slowly spread, often fatal, lower respiratory (lungs)

What are the two components of an antibody? What are they divided into?

Heavy chain and light chain; variable and constant regions

What is one way someone would not be affected by a virus?

Individuals with innate immunity lack receptors to even allow entry of H1N1 into the cell

Why is the not mitochondrion classified as part of the endomembrane system?

Its structure is not derived from the ER

Child experiences kidney failure due to Fabry's disease where the cells lining the inside of the kidney tubule accumulate abnormally large amounts of glycolipids that are usually degraded by enzymes. Which organelle was malfunctioning?

Lysosome

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition?

Lysosome

Which organelle contains hydrolytic enzymes?

Lysosome

In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which organelle functions in this compartmentalization?

Lysosomes

Eukaryote (basic definition)

Membrane-enclosed nucleus (animal and plant cells)

Cells can be described as having a cytoskeleton of internal structures that contribute to the shape, organization, and movement of the cell. What are the parts of the cytoskeleton?

Microfilaments (actin, microtubules, intermediate filaments)

Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide would be found within which organelle?

Mitochondria

Which organelle contains its own DNA?

Mitochondria

Which organelle is the main energy transformer of cells?

Mitochondria

List the semi-autonomous organelles

Mitochondria, chloroplast, peroxisome, cytoskeleton, glycocalyx, centrosome

The sperm of a man cannot swim thus rendering him infertile. Which organelle was malfunctioning?

Mitochondria--> flagella

Describe the trend between molecule size and polarity and membrane permeability

More polar and larger = less permeable (harder to get through the cell membrane)

Prokaryotic (basic definition)

No membrane-enclosed nucleus (bacteria)

A single cell in a smoker's lung has become cancerous. It doubles its DNA and divides much faster than a normal lung cell. The most likely change that would have caused this condition took place in the...

Nucleus or centrosome

List the organelles in the endomembrane system

Nucleus, rough ER (+ribosomes), smooth ER, Golgi, lysosomes, plasma membrane, vacuole

The liver is involved in detoxification of many poisons and drugs. Which structure is primarily involved int his process and therefore abundant in liver cells? (Hint: this organelle is a progenitor of the lysosome)

Peroxisome

Which organelle contains enzymes that transfer hydrogen from various substrates to oxygen?

Peroxisome

Compare and contrast cell structures between plant cells and animal cells: What major organelles/functions are unique to each?

Plant: photosynthesis (chloroplast)

What help overcome the hydrophobic barrier? Through what process?

Protein channels; facilitated diffusion

Why is a reassorted virus from bird or swine especially dangerous for humans? How might we come in contact with these viruses?

Reassortment of H and N (especially from other species) surprises our immune system. First farmers and people who come in direct contact with the animals get the virus then it spreads through other people

How doe scientists predict next season's flu strain to make a vaccine?

Reassortment... - Injecting two virus strains into a fertilized chick egg - Allowing the virus to undergo replication and new synthesis - Recombining their H and N capsid proteins. - Recombined viruses exit (resulting in quadrivalent vaccines to hopefully arm the immune system for multiple types)

What are the major components of an ideal prokaryotic cell? Typical size?

Ribosomes, cytoplasm, Pili, flagella, glycocalyx, plasma membrane, cell wall, nucleoid; 0.2-10 micrometers

Which structure is the site of protein synthesis that may be exported from the cell?

Rough ER

Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?

Smooth ER

What determines a virus' virility?

The capsid proteins

How do vaccines assist the immune system?

They stimulate the secretion of antibodies so that any future viral entry is marked and attacked by immune cells

Which organelle is a compartment that often takes up much of the volume in a plant cell?

Vacuole

Endocytosis

When a substance is taken into the cell by a vesicle through being engulfed by the PM

Exocytosis

When a vesicle fuses with the PM from inside the cell and substance is released outside the cell

Which structure is not part of the end-membrane system? a) Nuclear envelope b) Chloroplast c) Golgi d) PM e) ER

b) Chloroplast

Which of the following is present in a prokaryotic cell? a) Mitochondria b) Ribosome c) Nuclear envelope d) Chloroplast e) ER

b) Ribosome

Which statement correctly characterizes bound ribosomes? a) Enclosed in their own membrane b) Bound and free ribosomes are structurally different c) Generally synthesize membrane proteins and secretory proteins d) Most common location is the cytoplasmic surface of the PM e) all of the above

c) Bound ribosomes generally synthesize membrane proteins and secretory proteins

A cell has the following molecules and structures: DNA, ribosomes, PM, and mitochondria. It could be a cell from... a) a bacterium b) an animal, not a plant c) a plant, not an animal d) a plant or animal e) any kind of organism

d) plant or animal

Identify organelles of the eukaryotic secretory pathway and explain their structure and function

(Also look at slides)

Describe the modes of transmission for influenza virus

- *Horizontal*: transmitted along members of the same generation - Vertical: transmitted from mothers to offspring

Cytoskeleton (cell motility)

- Actin, microtubules, intermediate filaments - Provide support, give shape, cell motility, transport throughout the cell

What two factors are similar between plant and animal cells?

- DNA: housed in nucleus - Contains membrane-bound organelles - Large in size

Describe the interplay between viral components and eukaryotic components

1. Cell receptors recognize H1N1 epitopes 2a. Viral particle is engulfed in vesicle (endocytosis) and disassembles 2b. Vesicle is transported to nucleus via kinesin and microtubule track 2c. Capsid disassembles; viral and vesicle membranes merge; viral RNA released and guided to nucleus 3. Viral RNA is transcribed, processed (mature RNA...cap, splice, tail; capsid proteins) 4. Matures viral RNA (capsid protein) is exported from nucleus 5a. Translated by ribosomes 5b. Folded in ER, modified, sorted, and packaged in Golgi 5c. Capsid proteins embed in the host membrane 6. (Meanwhile, viral RNA is replicated, exported by vesicles to PM) 7a. Capsid proteins (w/ host membrane) self assemble with viral RNA 7b. New viral particle buds and infects another cell

How does vaccination work?

1. Injected with a universal flu vaccine 2. Virus is taken up by healthy cells 3. Cells containing vaccine attract immune cells which then multiply (cause the body to make specific antibodies) 4. Immune cells now primed to recognize proteins inside flu virus 5. Immune cells recognize future flu-infected cells and kill them along with the virus

Trace an antibody's cellular pathway for secretion by B cells by organelle (and function/structure)

1. Nuclear envelope (double bilayer for protection) 2. Nuclear pore (selective, regulated, mRNA exit) 3. Rough ER (polypeptide folded into Y) 3a. Ribosome (mRNA translated to polypeptide) 4. Smooth ER (lipid synthesis, packaged into vesicles) 5. Vesicle on microtubule track (hitching a ride with kinesin for transport) 6. Golgi (sort, modify, package, antibodies into vesicles, folding finalized) 7. Vesicle (transport along microtubule track) 8. PM (exocytosis, antibody secreted)

Typical size of a eukaryotic cell

5-100 micrometers

Compare and contrast plant vs. animal cell organelles

Animal: lysosome, centrosome Plant: Chloroplast, cell wall, central vacuole Same: all others

What does an antibody bind to? Where?

Antigen (epitope); H1N1 bind at the tips of the Y