Ch.2 Cellular Biology

Question 1

3 tenets of Cell Theory

Answer 1

All living organism are composed of one of more cells
Cells are the basic unit of life
All cells arise from preexisting cells

Question 2

Nuclear membrane (envelope) structure

Answer 2

double membrane/2 sets of phospholipid bilayers

Question 3

Nuclear pore function

Answer 3

protein complexes that allow selective transport of larger molecular across nuclear membrane (RNA, PT)

Question 4

Nucleolus

Answer 4

Within nucleus, assembles ribosomes

Question 5

Cytosol

Answer 5

gel-like aqueous solution that comprises the liquid found in cells

Question 6

Mitochondria genetic material

Answer 6

own circular DNA, inherited maternally, and undergoes binary fission

Question 7

How material enters Lysosome

Answer 7

material from outside cell enters lysosomes via endocytosis
material from inside cell enters through autophagy

At pH of 4.5-5.0 because enzymes function best in acid

Question 8

Endoplasmic Reticulum: smooth vs rough fucntion

Answer 8

Smooth ER: lipid metabolism (produces phospholipid components of membranes throughout cell), production of steroid hormones, and detoxification

Question 9

Golgi apparatus functions

Answer 9

Modifies its and packages proteins into membrane-bound vesicles that are sent to destination

Question 10

Peroxisomes

Answer 10

Where peroxides accumulate. Peroxisomes help metabolize very long chain lipids, breaking them down into medium-chain lipids that are transported to the mitochondria for further processing.
Also does detoxification of substances like ethanol

Question 11

Microfilaments

Answer 11

Composed of 2 stands of actin polymers. Responsible for cell mobility ends and exocytosis. Actin interacts with myosin for muscle contraction

Question 12

Microtubules

Answer 12

dimers of alpha and beta tubular. Helps maintain structure of cell, make up cilia and flagella, role in intracellular transport, and make up mitotic spindles (which sep chromosomes)

Question 13

Intermediate filaments

Answer 13

its that provide structural support and are involved in cellular adhesion process (e.g., keratin)

Question 14

Centrioles

Answer 14

made of tubulin; help organize mitotic spindle and are imp constituent of centrosome

Question 15

Centrosome

Answer 15

major microtubule organizing center within cell. Composed of two centrioles.

Question 16

Eukaryotic cilia and flagella structure

Answer 16

Cilia (moves subs along cell surface) and flagella (allow cell to move and can be sensory appendages) have 9+2 structure in eukaryotes—-9 pairs of microtubules in a ring that surround inner ring of two microtubules.

Question 17

Euk flagella vs Prok flagella

Answer 17

Euk flagella flap back and forth, with movement powered by ATP.
Pork flagella uses rotary motion and is powered by a proton gradient and composed of pt called flagellin

Question 18

Cholesterol and membrane fluidity

Answer 18

Cholesterol promotes fluidity at low temp by preventing crystal structures from being formed among phospholipid tails and promotes stability at high temp by inhibiting movement of phospholipids in lipid bilayer

Question 19

Shapes of bacterial

Answer 19

cocci = spherical
bacilli = rod
spirilli = spiral

Question 20

Obligate anaerobes

Answer 20

anaerobic metabolism and oxygen toxic

Question 21

aerotolerant anaerobes

Answer 21

anaerobic metabolism, but can live in oxygen envrionment

Question 22

facultative anaerobes

Answer 22

anaerobic or aerobic metabolism

Question 23

obligate aerobes

Answer 23

require oxygen for metabolism. Carry out aerobic metabolism within cell membrane

Question 24

Gram + vs Gram - bacterial cell walls

Answer 24

All bacterial cell walls contain peptidoglycan, a polysaccharid that gives rigidity to wall.
Gram + have a thick peptidoglycan cell wall that turns purple in gram staining
Gram - have a thin peptidoglycan cell wall with outer lipopolysaccharide layer. The lipopolysaccharide layer can induce innate immune response in humans causing inflammation.
Some antibiotics differ based on type of cell wall it targets

Question 25

Bacteria flagella structure

Answer 25

filament (made of flagellin), basal body (where rotation occurs), hook (connects the basal body of the filament)

Question 26

Virulence factors

Answer 26

coded for in plasmids and are anything that allows a bacterial infection to be more virulent or harmful to host

Question 27

Binary fission steps

Answer 27

realists in two daughter cells identical to parent | replication, segregation of DNA to opposite poles of bacterial, new cell wall grows, two daughter cells separate

Question 28

Horizontal gene transfer mechanisms

Answer 28

Increase genetic variability transformation: absorption of material directly from environment transduction: virus-mediated gene transfer. Viruses that infect bacteria (bacteriophages) and can incorporate part of bacterial genetic material into their genome and virus can then infect another bacterial cell and incorporate other bacterial cells genetic material conjugation: transfer of a plasmid through a bridge that is created when sex plus on one bacterium (F+ for fertility factor) attaches to another bacterium (F-). The fertility factor is duplicated and transferred creating a new F+ cell. This contributes to spread of antibiotic resistance

Question 29

Why are viruses called obligate intracellular parasites

Answer 29

because they must hijack host to replicate

Question 30

Viral capsid

Answer 30

protein coat

Question 31

Enveloped vs non-envelope viruses

Answer 31

enveloped are more sensitive to environment. E.g., HIV has to be transported vis bodily fluids because it has an envelope and thus cannot survive environment outside host

Question 32

Virion

Answer 32

fully-assembled infectious virus

Question 33

Types of single stranded viruses

Answer 33

+ sense: have mRNA that can be translated immediately by cell - sense: have RNA complementary to mRNA. It must by synthesized by RNA replicase that is carried in virion

Question 34

BACTERIOPHAGES

Answer 34

infect bacteria by injecting material into host via tail sheath instead of entering cell

Question 35

Retroviruses

Answer 35

single stranded. Use reverse transcriptase to synthesize DNA from RNA. Incorporates DNA into genome of host cell, where it replicates along host - cannot be killed without killing host

Question 36

Viral life cycle

Answer 36

Lytic cycle: bacteriophage replicates in host using host machinery. Eventually host cell bursts or lyses (host killed) and new virions spill into environment Lysogenic cycle: bacteriophage integrates itself into host genome--- now referred as prophage/provirus

Question 37

Prions

Answer 37

misfolded infectious proteins that cause other proteins to misfold

Question 38

Viroids

Answer 38

small infectious particles in plants that can silence gene expression by binding to specific RNA sequences

Question 39

Cell Cycle

Answer 39

``` Interphase G1: Cell Growth G0: non-dividing G1/S check point: has cell grown enough/ If so, committed to division S: DNA duplicates G2: cell prepares for mitosis G2/M checkpoint; is DNA duplicated? Can cell divide? M Phase/Mitosis: PMAT ```

Question 40

Prok vs Euk genetic info

Answer 40

Prok circular DNA usually in cytoplasm | Euk DNA linear, found in nucleus

Question 41

Prok vs Euk Ribosome size

Answer 41

Prok: 30s and 50s Euk: 40s and 60s