The cell

Question 1

Eukaryotic cells vs. prokaryotic

Answer 1

Eukaryotic:
-Has true nucleus
-Has membrane bound organelles
-Can be unicellular or multicellular

Prokaryotic:
-No real nucleus
-No membrane bound organelles
-Unicellular

Question 2

Nucleus

Answer 2

Contains chromosomal/genetic information
-Has double membrane called envelope, including pores that allow proteins in and out

Question 3

Where is the nucleolus found and what does it do?

Answer 3

Found within the nucleus

Site of rRNA formation

Question 4

What is the purpose and make-up of the mitochondria?

Answer 4

Produces ATP, also the site of electron transport chain and citric acid cycle, and can cause apoptosis

Has a double membrane that consists of an inner membrane (mitochondrial matrix), outer membrane, and intermembrane space

Question 5

What is special about the mitochondria’s DNA?

Answer 5

-It is circular and can replicate through binary fission, separate from nuclear DNA replication
-Double stranded
-Extranuclear inheritance- means it can transmit genetic info without the nucleus (all mitochondria inherited from maternal side)

Question 6

What purpose do lysosomes serve?

Answer 6

Hydrolyze cellular waste by engulfing foreign bodies
-Done through endocytosis or with waste already inside cell
-Can also cause apoptosis if they lyse and spread acidic material into cell

Question 7

What are the two sections of Endoplasmic Reticulum and what do they do?

Answer 7

Rough ER:
-Has ribosomes
-Site of protein synthesis

Smooth ER:
-Lacks ribosomes
-Lipid synthesis, detox, and transports proteins to Golgi body

Question 8

What role does the golgi body play?

Answer 8

“Mail room” of the cell

Receives proteins from ER, packages/modifies them, and sends them to correct location
-Also performs exocytosis (sending something outside the cell)

Question 9

What role do peroxisomes play?

Answer 9

Neutralize oxidizers in the cell
-breakdown of fatty acids through beta-oxidation

Question 10

What are the 3 components of the cytoskeleton?

Answer 10

Microfilaments, intermediate filaments, and microtubules

Question 11

What are microtubules made up of, and what structures can they create?

Answer 11

Tubulin

-Make paths for “walking proteins”
-Make up cilia and flagella
-Make up centrioles/mitotic spindles

Question 12

What are microfilaments made up of, and what structures can they create?

Answer 12

Actin

-Provides cellular protection
-Forms cleavage furrow
-Used in muscle contractions

Question 13

What are intermediate filaments made up of, and what structures can they create?

Answer 13

Made up of diverse # of proteins

-Cell-to-cell adhesions
-Cytoskeleton integrity
-Anchors organelles

Question 14

What is epithelial tissue and what role does it play?

Answer 14

The tissue that covers the body and lines cavities/the functional part of organs

Protects against pathogens

Question 15

What are the three types of epithelial tissues?

Answer 15

Simple –> one layer of cells
Stratified –> multiple layers of cells
Pseudo-stratified –> Appears as though there’s multiple layers, but there’s really only one

Question 16

What are the three shapes of epithelial tissues?

Answer 16

Cuboidal –> cubes
Columnar –> long and thin
Squamos –> flat and scale-like

Question 17

Connective tissue makes up the ____ and secretes materials to form the _____

Answer 17

Stroma

Forms the extracellular matrix

Attaches to epithelial tissue to support the body and create framework for epithelial cells

Question 18

What are the three shapes of bacteria?

Answer 18

Cocci –> spherical
Bacilli –> rod
Spirilli –> spiral

Question 19

What is the difference between obligate and facultative aerobes/anaerobes?

Answer 19

Obligate means the cell absolutely can or cannot have air

Facultative means the cell can switch between needing air or not needing air depending on the situation

Question 20

In prokaryotes, what is recombination?

Answer 20

Plasmids on the outside of the cell carry genetic information that can be transferred to other cells

Question 21

In prokaryotes, what is transformation?

Answer 21

The integration of foreign material into the host genome

Question 22

In prokaryotes, what is conjugation?

Answer 22

Sexual reproduction, where F+ cell will use its sex pillus to form a conjugation bridge and pass the material from the F+ male to F- female

-This can only occur between a F+ and F- cell, after which both cells will be F+

Question 23

In prokaryotes, what is transduction?

Answer 23

Requires a vector (virus that carries genes from one bacteria to another)
-usually occurs from accidental transfer from bacteriophages

Question 24

What are the bacteria growth phases?

Answer 24

Lag –> bacteria adapts to new environment
Log (exponential)–> bacteria begins to rapidly replicate
Stationary –> reducation of resources slows down replication
Death –> resources are depleted so cells cannot survive

Question 25

What kind of DNA do viruses have?

Answer 25

Any kind: double or single stranded, circular or linear, RNA or DNA

Question 26

What is the difference between positive and negative sense RNA?

Answer 26

Always single stranded

Positive sense is ready to be translated into proteins (think of it like mRNA)

Negative sense acts as a template for a complimentary strand, which is then used as a protein synthesis template
-Requires RNA replicase

Question 27

What is the life cycle of viruses?

Answer 27

Infection –> the virus binds to target cells by binding to receptors or fusing with plasma membrane

Translation/progeny assembly –> genetic material goes to the proper location where it is then translated into proteins, which in turn creates new viroids

Progeny release –> Can either be done through cell lysing (disadvantage –> kills cell so it can’t make any more viroids) or through extrusion where viroids pinch off membrane and enter the body

Question 28

What is the difference between the lytic and lysogenic phase for bacteriophages?

Answer 28

Lytic phase occurs when the bacteriophage harnesses the cell to continuously create new virons (virulent phase)

Lysogenic phase occurs when the bacteriophage’s genetic material is sitting dormant in the cell
-The genetic material fuses with the bacteria and is replicated with that bacteria
-Certain conditions cause return to lytic phase

Question 29

What are prions?

Answer 29

Implicated in the misfiling of proteins