final exam

Question 1

where is mitochondria located within the cell?

Answer 1

cytoplasm of both plant and animal cells

Question 2

how are mitochondrial disease inherited?

Answer 2

maternally
- mitochondria transferred from oocyte
- cytoplasmic inheritance (non-mendelian inheritance)
- all offspring from affected mother will have disease

Question 3

list mitochondrial disorders

Answer 3

• leber hereditary optic neuropathy
• kearns-sayre syndrome
• myoclonic epilepsy with ragged red fibers

Question 4

what is the main function of mitochondria?

Answer 4

conducts krebs cycle and ETC to generate ATP via oxidative phosphorylation

Question 5

where would you find chloroplasts?

Answer 5

plant cells

Question 6

what are the three filaments of the cytoskeleton?

Answer 6

actin (microfilaments)
intermediate
microtubules

Question 7

what makes up microtubules?

Answer 7

alpha and beta tubulin

Question 8

what makes up actin filaments?

Answer 8

globular proteins that can assemble and disassemble within the cell (through polymerization and depolymerization

Question 9

what makes up intermediate filaments?

Answer 9

bunch of different size polypeptides (fibrous protein subunits), makes a trimer and is more stable than actin and microtubules

Question 10

what cells and cell structures would you find microfilaments in?

Answer 10

muscle fibers (skeletal muscle cell)
sarcomere (A and I band)

Question 11

what is the energy source required for the polymerization of tubulin and actin?

Answer 11

tubulin- GTP
actin- ATP

Question 12

describe the structure of cilia

Answer 12

• bundles of microtubules
• core=axoneme
• 9+2 pattern at axoneme
• basal body where microtubules can grow 9+0 pattern
• dynein present on 9+2 arrangement

Question 13

explain Kartagener’s syndrome

Answer 13

• autosomal recessive disorder that affects the motor protein dynein in the individuals body.
• recurrent upper respiratory tract infections, chronic sinusitis, and infertility in males (due to the inability of the sperm to travel, situs inversus with dextrocardia

Question 14

colchicine

Answer 14

• prevents polymerization of microtubules by binding to a tubulin dimer
• halts cell division -> anti-mitotic and anti cancer drug

Question 15

vincristine and vinblastine

Answer 15

anti-mitotic drug used as anti-cancer cells since they can preferentially kill rapidly dividing cells found in cancer
- affects microtubules

Question 16

taxol

Answer 16

• prevents depolymerization of microtubules by increasing polymerization by depleting cytoplasmic pool of tubulin
• stabilizes microtubule
• anti-mitotic

Question 17

cytochalasins

Answer 17

• prevent polymerization of actin by binding specifically to one end of actin filament and preventing addition of more actin molecules to that end
• metabolites released by different molds

Question 18

phalloidin

Answer 18

• death cap mushrooms
• prevents depolymerization of actin by stabilizing actin filaments
• commonly used as cytoskeletal stain

Question 19

describe interphase

Answer 19

where the cell grows and spends the most time in to prepare itself to divide

Question 20

describe G1 phase

Answer 20

• occurs right after mitosis
• acts a gap for cell before needing to replicate its DNA to prepare again for cell division

Question 21

describe S phase

Answer 21

synthesizes DNA
- cell replicates its DNA in preparation for division

Question 22

describe G2 phase

Answer 22

second gap of interphase

Question 23

describe M phase

Answer 23

mitosis

Question 24

what is G0 phase

Answer 24

becomes senescent during G1 phase

Question 25

what is the purpose of p53?

Answer 25

- tumor suppressor gene - caretaker protein "guardian of the genome" - 50% human cancers have mutations of it *ensures DNA's integrity is maintained* - if it notices any DNA damage, arrests cell in G1/S checkpoint and activates DNA repair mechanisms - arrests cell through CDK inhibitor p21 - if damage can't be repaired, activates apoptosis via BAX

Question 26

what is retinoblastoma?

Answer 26

- childhood cancer that occurs due to a mutation in the Rb gene which is located on chromosome 13 - In order to develop a cancer in this mechanism, both genes must have a loss of function. - “familial cancer” because most children inherit one defective Rb allele from a parent who is a carrier. - symptoms of retinoblastoma are leukocoria — which is the abnormal white appearance of the retina upon examination, loss of vision, glaucoma, or cross-eyed vision.

Question 27

what is mitosis and its purpose?

Answer 27

cell division to create identical daughter cell

Question 28

prophase

Answer 28

nucleoli breakdown and DNA condenses into chromosomes

Question 29

prometaphase

Answer 29

nuclear envelopes breaks down and kinetochores attach to microtubules

Question 30

metaphase

Answer 30

chromosomes lined up on equator of cell

Question 31

anaphase

Answer 31

chromosomes split into chromatids that travel to opposite ends of cell

Question 32

telophase

Answer 32

sister chromatids are separated and have arrived at opposite poles and kinetochore microtubules begin to disappear

Question 33

cytokinesis

Answer 33

cleavage furrow along with contractile rings causes cell to separate into two identical daughter cells

Question 34

define chemotaxis

Answer 34

directed motion of organism towards chemical signal

Question 35

define adhering junctions

Answer 35

mechanically hold cell together typically through desmosomes (belt, spot, hemi)

Question 36

define impermeable junctions

Answer 36

hold cells together and also make seal so molecules can't pass in between them typically through tight junction

Question 37

define communicating junctions

Answer 37

allow cells to communicate with each other most commonly through gap junctions and chemical synapses

Question 38

what is bullous pemphigoid?

Answer 38

- disease characterized by blister formation causing the epithelium to detach from the basal lamina - caused by an autoimmune attack on different protein components of the hemidesmosome - pruritic (itchy) skin disease that is common in people over the age of 60. - presence of bullous pemphigoid blisters can be a side effect of certain drugs like furosemide (Lasix) which is a loop diuretic or Vildagliptin, an antidiabetic drug

Question 39

What are the fibers and proteins that make up the extracellular matrix?

Answer 39

fibroblasts collagen glycosaminoglycans elastin

Question 40

what is osteogenesis imperfecta type I?

Answer 40

- caused by a mutation in either of the type I collagen genes: COL1A1 and COL1A2 - long bone fractures in their childhood which occur after minor trauma, mistaken for abuse - possibility of hearing loss, and will have blue sclera

Question 41

what is marfan syndrome?

Answer 41

- autosomal dominant disorder that is caused by a mutation in the fibrillin-1 (FBN1) gene on chromosome 16. - long limbs, arachnodactyly, pectus excavatum, lens dislocation, aortic aneurysm, and abnormal formation of the rib cage.

Question 42

merocrine secretion

Answer 42

cell secretes signal without damage to itself - sweat and mammary glands

Question 43

holocrine secretion

Answer 43

whole cell expelled during secretion and ruptured cell becomes part of secretory product - sebaceous glands

Question 44

apocrine secretion

Answer 44

only apical part of cell shed in secretory product - sweat glands in armpit